Abstract
Background
The global Study of Monitoring Antimicrobial Resistance Trends (SMART) is a surveillance program for evaluation of antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) from different regions including Gulf countries.
Objectives
To evaluate AMR in GNB from various clinical specimens including microbiological and genetic characteristics for existing and novel antimicrobials.
Methods
A prospective study was conducted on clinical specimens from Hamad Medical Corporation, Qatar, between 2017 and 2019 according to the SMART protocol. Consecutive GNB from different sites were evaluated including lower respiratory, urinary tract, intrabdominal and bloodstream infections.
Results
Over the 3 years study period, 748 isolates were evaluated from the specified sites comprising 37 different GNB outlining four key pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia.
For the two major pathogens E. coli and K. pneumoniae, phenotypic ESBL was identified in 55.77% (116/208) compared to 39% (73/187), while meropenem resistance was 3.8% compared to 12.8% and imipenem/relebactam resistance was 2.97% compared to 11.76%, respectively. The overall ceftolozane/tazobactam resistance for E. coli was 9.6% (20/208) compared to 14.97% (28/187) for K. pneumoniae while resistance for ceftazidime/avibactam was 3.65% (5/137) and 5.98% (10/117), respectively. Genomic characteristics of 70 Enterobacterales including 48 carbapenem-resistant, revealed prevalence of β-lactamases from all classes, predominated by blaCXM-15 while carbapenem resistance revealed paucity of blaKPC and dominance of blaOXA-48 and blaNDM resistance genes.
Conclusions
Surveillance of GNB from Qatar showed prevalence of key pathogens similar to other regions but demonstrated significant resistance patterns to existing and novel antimicrobials with different underlying resistance mechanisms.
Background
In modern healthcare, challenges of antimicrobial resistance (AMR) have a major impact on public health, with significant morbidity and mortality as well as escalating costs of management.1 The consequences of AMR are particularly witnessed in Gram-negative bacteria (GNB) where the pathogens are responsible for a wide spectrum of community and healthcare-associated infections (HAIs), ranging from mild to severe that require critical care and frequently fatal outcomes. Over the last decades, the accumulation of diverse resistance mechanisms in GNB, led to the development of the notorious multidrug resistant organisms (MDROs) with critical consequences.1,2 The emergence of MDROs with limited therapeutic alternatives, has been associated with detrimental patient outcomes leading to prolonged length of hospital stay that necessitates urgent prevention and control strategies that include the development of novel antimicrobials options.3 Globally GNB encompassing MDROs, are the leading cause of human infections for all age groups, as they are the principal cause of urinary tract infections (UTIs) as well as hospital-acquired respiratory tract infections (RTIs).4,5 Similarly, they are amongst the leading causes of nosocomial bacteraemia as well as complicated or uncomplicated intra-abdominal infections (IAIs).6–9
When examining the global problem of AMR, it is clear it has regional variations attributed to pathogens and host factors as well as variance in local settings including antimicrobial prescribing choices and consumption, dominance of highly resistant clones as well as variable adherence to infection control and prevention measures.10 Furthermore, regional epidemiology does not only differ in prevalence, but also in microbiological characteristics and underlying resistance mechanisms. While extended-spectrum β-lactamases (ESBLs) are the most observed global resistance mechanism in GNB including Enterobacterales, other advanced mechanisms such as those observed in carbapenem-resistant Enterobacterales (CREs) have a different disease spectrum and are predicted to pose significant future challenges.1 In CREs, the underlying mechanisms of AMR are diverse, for example, while class A blaKPC is the dominant mechanism in North America and Europe, class B such as blaNDM, blaVIM as well as class D blaOXA type CREs are dominant in the Middle East and Gulf countries.11 Similarly, for Pseudomonas aeruginosa and Acinetobacter baumannii, resistance mechanisms are dominated by ESBLs and class C cephalosporinases in addition to other antimicrobial permeability resistance mechanisms such as efflux pumps and porins mutations that are unique in the study of the evolution resistance in GNB.12,13 Furthermore, antimicrobial characteristics for existing and novel antimicrobials therapy demonstrate regional variations that merit further evaluation to enhance clinical experience as well as aid research and development of future antimicrobial therapy.14
The high rate of AMR calls for accurate regional and global surveillance to assess pathogens epidemiology, microbiological and genomic characteristics that remains of paramount importance at all levels particularly for guidance of appropriate antimicrobial therapy. Consequently, in 2015, the World Health Organization developed a global AMR action plan that advocates regional and national monitoring strategies including implementing viable surveillance concepts.15
This study is part of the global surveillance of AMR in collaboration with the International Health Management Associates, Inc (IHMA), examining microbiological and genomic characteristics of selected GNB between 2017 and 2019 from Qatar. It includes the evaluation of in vitro susceptibility of GNB to the novel antimicrobial agents: imipenem/relebactam, ceftolozane/tazobactam, ceftazidime-avibactam and meropenem-vaborbactam compared to existing comparators from clinical practice, as well as molecular characterization of ESBLs, carbapenemases, plasmid and chromosomally encoded AmpC β-lactamases from specific aerobic Gram-negative species.
Materials and methods
Bacterial strains
All isolates were collected from specimens received at the central microbiology laboratory in Qatar according to the criteria in the SMART protocol as outlined. The laboratory receives specimens from 10 general and specialized facilities within Hamad Medical Corporation, which is the main provider of hospital services within the State of Qatar.
Specimens were collected from hospitalized patients from designated facilities. For each year of the study, consecutive clinically relevant isolates of aerobic GNB were collected from patients with lower RTIs (100 isolates), UTIs, (50 isolates) and IAIs (50 isolates) as well as from bloodstream infections (BSIs) (50 isolates). Only one isolate per patient per species was allowed. Isolate demographic information was documented on provided worksheets as per the study protocol. Following local identification using automated BD Phoenix™ Microbiology System (BD Diagnostics, Durham, NC, USA), isolates were transferred to IHMA for further analysis. Identification of all isolates received at each testing facility were confirmed using MALDI-TOF spectrometry (Bruker Daltonics, Billerica, MA, USA). Organism collection, transport, identification and confirmation, quality assurance and centralized database development and management were coordinated by IHMA (Schaumburg, IL, USA). Results were extracted and analysed from the central database by the study reporting group: https://globalsmartsite.com
Antimicrobials susceptibility testing (ASTs)
Minimum inhibitory concentrations (MICs) were determined at IHMA’s US and European laboratories using frozen in-house custom or commercially available broth microdilution panels. Separate custom panel configurations were made for isolates of Enterobacterales and Gram-negative non-fermenter species (Acinetobacter species, Pseudomonas species and Burkholderia species). All broth microdilution tests were set up according to the Clinical and Laboratory Standards Institute (CLSI) guidelines and MIC interpretive criteria used were those published in 2020 M100 guidelines by CLSI.16 Because not all GNB are tested against standard antimicrobial panels as well as some protocol changes during collection period that allowed incremental introduction of novel antimicrobials, not all isolates were uniformly tested against designated antimicrobials, which explains the non-congruent figures. Additionally, interpretive criteria for imipenem/relebactam were those assigned by CLSI, EUCAST and the United States Food and Drug Administration (US FDA).
Using CLSI guidelines, Escherichia coli, Klebsiella pneumoniae, K. oxytoca and Proteus mirabilis were classified as ESBL producers if there was at least an 8-fold reduction (i.e. three doubling dilutions) of the MIC for ceftazidime or cefotaxime tested in combination with clavulanic acid versus their MIC values when tested alone.16 Quality control (QC) of broth microdilution panels followed the manufacturer’s instructions and CLSI guidelines, using the following ATCC strains: E. coli ATCC 25922, P. aeruginosa ATCC 27853, K. pneumoniae ATCC 700603 and K. pneumoniae BAA-2814. Results were included in the analysis only when corresponding QC values tested were within the acceptable ranges as specified by CLSI.
Molecular characterization of β-lactamase genes
Enterobacterales isolates that met one or more of the following criteria (based on CLSI breakpoints) were screened for the presence of β-lactamase genes: Enterobacterales non-susceptible to ceftolozane/tazobactam (MICs ≥4 mg/L) and non-Morganellaceae Enterobacterales, excluding Serratia species, non-susceptible to imipenem (MICs ≥2 mg/L) and/or imipenem/relebactam (MICs ≥2 mg/L). P. aeruginosa isolates that met one or more of the following criteria were screened for the presence of β-lactamase genes: isolates non-susceptible to ceftolozane/tazobactam (MICs ≥8 mg/L) and isolates non-susceptible to imipenem (MICs ≥4 mg/L) and/or imipenem/relebactam (MICs ≥4 mg/L). The proportion of isolates that met the testing criteria that were characterized was determined based on budgetary constraints which included 70 MDR-GNB and 48 CREs. Qualifying Enterobacterales isolates were screened for the presence of β-lactamase genes (bla) encoding class A ESΒLs blaTEM, blaSHV, blaCTX-M, blaVEB, blaPER, and blaGES; blaAmpC, class B metallo-β-lactamase (MBL) genes blaNDM, blaIMP, blaVIM, blaGIM and blaSPM, class C β-lactamase genes blaACC, blaACT, blaCMY, blaDHA, blaFOX, blaMIR and blaMOX; class A carbapenemases blaKPC and blaGES and class D blaOXA-48-like, by multiplex PCR as described previously.17
Data handling and statistical analysis
Summary of statistics were calculated using R software v.4.1.3. The total number of isolates (n), MIC50 (mg/L), MIC90 (mg/L) and MIC range (mg/L) were determined for all antimicrobial agents tested. The percentage of susceptibility (%) was calculated according to both CLSI and EUCAST where available. Direct comparisons were made between different interpretive criteria using published breakpoints for each drug.
Ethical considerations and data management
The study and collaboration were approved by the Medical Research Centre of Hamad Medical Corporation (HMC), which abides by local and international research standards (ref. 17248/17). The study also received approval from the Ethical Committee and Institution Review Board of HMC after demonstrating utmost commitment towards observing outlined standards for data management and sharing including limited access to nominated primary investigators, data anonymity and governance. All shared data with collaborators had no traced patients’ identification.
Results
Prevalence and distribution of aerobic GNB isolates
The frequency and distribution of all isolated GNB is shown in Table 1. Thirty-seven different GNB species were isolated, with predominance of four key species accounting for about 80% of infections: E. coli (27.9%), K. pneumoniae (25%), P. aeruginosa (21.9%) and Stenotrophomonas maltophilia (6%) while organisms from the order Enterobacterales constituted 67.25% (503/748) of infections. Identified pathogens were isolated from RTIs 39.84% (298/748), IAIs 23.80% (178/748), UTIs at 23.53% (176/748) and BSIs at 12.83% (96/748). P. aeruginosa was the most common cause of RTIs and E. coli was the most common cause of infections from the three other outlined sites.
Table 1.
Species | Year of isolation | Site of isolation | Frequency | % | ||||||
---|---|---|---|---|---|---|---|---|---|---|
2017 | 2018 | 2019 | RT | IA | UT | BS | Unknown | |||
Escherichia coli | 72 | 73 | 64 | 8 | 77 | 76 | 48 | 0 | 209 | 27.94% |
Klebsiella pneumoniae | 70 | 59 | 58 | 68 | 44 | 55 | 20 | 1 | 187 | 25% |
Pseudomonas aeruginosa | 53 | 46 | 65 | 108 | 25 | 18 | 13 | 0 | 164 | 21.93% |
Stenotrophomonas maltophilia | 10 | 22 | 13 | 39 | 5 | 0 | 1 | 0 | 45 | 6.02% |
Enterobacter cloacae | 10 | 9 | 7 | 14 | 7 | 3 | 2 | 0 | 26 | 3.48% |
Serratia marcescens | 7 | 3 | 10 | 15 | 2 | 2 | 1 | 0 | 20 | 2.67% |
Acinetobacter baumannii | 8 | 5 | 6 | 15 | 1 | 3 | 1 | 0 | 19 | 2.54% |
Klebsiella aerogenes | 5 | 4 | 2 | 6 | 1 | 3 | 1 | 0 | 11 | 1.47% |
Proteus mirabilis | 4 | 3 | 3 | 1 | 0 | 7 | 2 | 0 | 10 | 1.34% |
Klebsiella variicola | 1 | 3 | 4 | 3 | 3 | 0 | 2 | 0 | 8 | 1.07% |
Enterobacter non-speciated | 2 | 4 | 0 | 5 | 1 | 0 | 0 | 0 | 6 | 0.80% |
Morganella morganii | 2 | 1 | 2 | 0 | 1 | 3 | 1 | 0 | 5 | 0.67% |
Citrobacter freundii | 1 | 3 | 0 | 1 | 1 | 1 | 1 | 0 | 4 | 0.53% |
Salmonella non-speciated | 0 | 1 | 3 | 0 | 4 | 0 | 0 | 0 | 4 | 0.53% |
Acinetobacter non-speciated | 0 | 2 | 1 | 2 | 0 | 1 | 0 | 0 | 3 | 0.40% |
Achromobacter xylosoxidans | 1 | 1 | 0 | 2 | 0 | 0 | 0 | 0 | 2 | 0.27% |
Acinetobacter pittii | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 2 | 0.27% |
Aeromonas caviae | 1 | 1 | 0 | 0 | 2 | 0 | 0 | 0 | 2 | 0.27% |
Klebsiella oxytoca | 1 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 2 | 0.27% |
Proteus non-speciated | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 2 | 0.27% |
Aeromonas hydrophila | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0.13% |
Aeromonas veronii | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0.13% |
Burkholderia cenocepacia | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Burkholderia cepacia | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Burkholderia multivorans | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Citrobacter koseri | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Elizabethkingia miricola | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Enterobacter bugandensis | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Kluyvera ascorbata | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0.13% |
Pantoea non-speciated | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0.13% |
Proteus hauseri | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0.13% |
Proteus penneri | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0.13% |
Providencia stuartii | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0.13% |
Pseudomonas non-speciated | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Pseudomonas otitidis | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Ralstonia non-speciated | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0.13% |
Raoultella ornithinolytica | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | 0.13% |
Total (%) | 250 (33.42) | 250 (33.42) | 248b (33.16) | 298 (39.84) | 178 (23.80) | 176 (23.53) | 96 (12.83) | 1 (0.13) | 748 (100) | 100% |
BS, blood stream; IA, intra-abdominal; RT, respiratory tract; UT, urinary tract.
Demographic profile of study population
The 748 specimens were collected from all age groups (0–99 years), with male preponderance (64.17%). Specimens were from medical, surgical and paediatrics departments while 39.1% of samples were from intensive and critical care units (Supplementary Table S1, available as Supplementary data at JAC-AMR Online).
Antimicrobial susceptibility patterns of GNB isolates
Antimicrobial susceptibility test results for the top 10 species-comprising 699 isolates (93.4%) of the study organisms, are summarized in Table 2.
Table 2.
Species | No. of isolates | AST | Amikacin | Aztreonam | Cefepime | Cefotaxime | Cefoxitin | Ceftazidime | Ceftazidime-avibactam | Ceftolozane-tazobactam | Ceftriaxone | Ciprofloxacin | Colistin | Ertapenem | Imipenem | Imipenem-relebactam | Levofloxacin | Meropenem | Meropenem-vaborbactam | Piperacillin-tazobactam | Tobramycin |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Escherichia coli | 209 | No. of tested isolates | 209 | 209 | 209 | 72 | 209 | 209 | 137 | 209 | 209 | 145 | NA | 209 | 209 | 209 | 209 | 209 | 64 | 209 | NA |
Susceptible (%) | 205 (98.09%) | 104 (49.76%) | 107 (51.20%) | 28 (38.89%) | 143 (68.42%) | 107 (51.20%) | 132 (96.35%) | 188 (89.95%) | 92 (44.02%) | 52 (35.86%) | 198 (94.74%) | 201 (96.17%) | 203 (97.13%) | 55 (26.32%) | 201 (96.17%) | 62 (96.88%) | 179 (85.65%) | ||||
Klebsiella pneumoniae | 187 | No. of tested isolates | 187 | 187 | 187 | 70 | 187 | 187 | 117 | 187 | 187 | 129 | NA | 187 | 187 | 187 | 187 | 187 | 58 | 187 | NA |
Susceptible (%) | 179 (95.72%) | 124 (66.31%) | 122 (65.24%) | 45 (64.29%) | 144 (77.01%) | 120 (64.17%) | 110 (94.02%) | 159 (85.03%) | 114 (60.96%) | 77 (59.69%) | 160 (85.56%) | 161 (86.10%) | 165 (88.24%) | 77 (41.18%) | 163 (87.17%) | 50 (86.21%) | 140 (74.87%) | ||||
Pseudomonas aeruginosa | 164 | No. of tested isolates | 164 | 164 | 164 | NA | NA | 164 | 111 | 164 | NA | 99 | 164 | NA | 164 | 164 | 164 | 164 | NA | 164 | 111 |
Susceptible (%) | 160 (97.56%) | 105 (64.02%) | 126 (76.83%) | 120 (73.17%) | 104 (93.69%) | 156 (95.12%) | 51 (51.52%) | 0 (0.00%) | 115 (70.12%) | 150 (91.46%) | 125 (76.22%) | 120 (73.17%) | 112 (68.29%) | 108 (97.30%) | |||||||
Stenotrophomonas maltophilia | 45 | No. of tested isolates | NA | NA | NA | NA | NA | 45 | NA | NA | NA | NA | NA | NA | NA | NA | 45 | NA | NA | NA | NA |
Susceptible (%) | 15 (33.33%) | 34 (75.56%) | |||||||||||||||||||
Enterobacter cloacae | 26 | No. of tested isolates | 26 | 26 | 26 | 13 | 26 | 26 | 16 | 26 | 26 | 22 | NA | 26 | 26 | 26 | 26 | 26 | 7 | 26 | NA |
Susceptible (%) | 25 (96.15%) | 20 (76.92%) | 23 (88.46%) | 8 (80%) | 1 (4.35%) | 20 (76.92%) | 16 (100%) | 20 (76.92%) | 19 (27.08%) | 16 (84.21%) | 23 (88.46%) | 23 (88.46%) | 24 (92.31%) | 16 (61.54%) | 24 (92.31%) | 7 (100%) | 20 (76.92%) | ||||
Serratia marcescens | 20 | No. of tested isolates | 20 | 20 | 20 | 7 | 20 | 20 | 13 | 20 | 20 | 10 | 20 | 20 | 20 | 20 | 20 | 10 | 20 | NA | |
Susceptible (%) | 20 (100%) | 20 (100%) | 19 (95%) | 7 (100%) | 1 (5%) | 20 (100%) | 13 (100%) | 19 (95%) | 17 (85%) | 9 (90%) | NA | 19 (95%) | 14 (70%) | 17 (85%) | 11 (55%) | 19 (95%) | 9 (90%) | 18 (90%) | |||
Acinetobacter baumannii | 19 | No. of tested isolates | 19 | NA | 19 | 9 | NA | 19 | NA | NA | 9 | 19 | 19 | NA | 19 | NA | 19 | 19 | NA | 19 | 11 |
Susceptible (%) | 12 (63.16%) | 11 (57.89%) | 2 (25.00%) | 12 (63.16%) | 0 | 8 (61.54%) | 0 | 12 (63.16%) | 11 (57.89%) | 12 (63.16%) | 11 (57.89%) | 8 (72.73%) | |||||||||
Klebsiella aerogenes | 11 | No. of tested isolates | 11 | 11 | 11 | 5 | 11 | 11 | 6 | 11 | 11 | 9 | 11 | 11 | 11 | 11 | 11 | 11 | 2 | 11 | NA |
Susceptible (%) | 11 (100%) | 9 (81.82%) | 11 (100%) | 3 (60.00%) | 0 | 8 (72.73%) | 6 (100%) | 10 (90.91%) | 8 (72.73%) | 6 (66.67%) | 11 (100%) | 11 (100%) | 10 (90.91%) | 11 (100%) | 5 (45.45%) | 11 (100%) | 2 (100%) | 9 (81.82%) | |||
Proteus mirabilis | 10 | No. of tested isolates | 10 | 10 | 10 | 4 | 10 | 10 | 6 | 10 | 10 | 7 | NA | 10 | 10 | 10 | 10 | 10 | 3 | 10 | NA |
Susceptible (%) | 10 (100%) | 9 (90%) | 9 (90%) | 2 (50.00%) | 9 (90%) | 9 (90%) | 6 (100%) | 9 (90%) | 8 (80%) | 5 (71.43%) | 10 (100%) | 8 (80%) | 9 (90%) | 5 (50%) | 10 (100%) | 3 (100%) | 10 (100%) | ||||
Klebsiella variicola | 8 | No. of tested isolates | 8 | 8 | 8 | 1 | 8 | 8 | 7 | 8 | 8 | 4 | NA | 8 | 8 | 8 | 8 | 8 | 4 | 8 | NA |
Susceptible (%) | 8 (100%) | 8 (100%) | 8 (100%) | 1 (100%) | 8 (100%) | 8 (100%) | 7 (100%) | 8 (100%) | 8 (100%) | 4 (100%) | 6 (75%) | 6 (75%) | 6 (75%) | 7 (87.5%) | 7 (87.5%) | 4 (100%) | 6 (75%) |
Susceptibility tests were reported according to breakpoints of the CLSI 2020 Edition.
Assessment of the AST of the 503 clinical isolates of Enterobacterales demonstrated that the aminoglycoside amikacin was the most potent, ranging between 95.72% and 100%. E. coli demonstrated the highest phenotypic detection of extended-spectrum β-lactamases (ESBLs) at 55.77% (116/208) compared to 39.04% (73/187) for K. pneumoniae. Conversely, carbapenem susceptibility patterns of Enterobacterales isolates (E. coli, K. pneumoniae, E. cloacae, S. marcescens, P. mirabilis, K. varicola and K. aerogenes) were highly retained being lowest for K. pneumoniae (96.17%, 87.17%, 92.31%, 95%, and 100%, respectively). Additionally, further exploration for the new β-lactams/β-lactamase inhibitors (BLBLIs) combinations revealed highest activity for ceftazidime/avibactam with low level resistance (E. coli, 3.65%, K. pneumoniae 3.98% while for E. cloacae, S. marcescens and K. aerogenes at 0%), respectively.
For the broad BLBLIs, imipenem/relebactam resistance rates were 2.97% for E. coli (5/208) compared to 11.76% (22/187) for K. pneumoniae. Similarly, for E. coli, the overall ceftolozane/tazobactam resistance was 9.62% (20/208) compared to 14.97% (28/187) for K. pneumoniae while resistance for ceftazidime/avibactam was 3.65% (5/137) and 5.98% (10/117), respectively (Table 2).
Furthermore, assessment of antibacterial activity of 164 P. aeruginosa isolates and 19 A. baumannii isolates are shown in Table 2. All P. aeruginosa isolates showed 100% susceptibility to colistin, with slightly reduced susceptibility to amikacin (97.56%) and tobramycin (97.30%). Unlike other BLBLIs combinations highest susceptibility was observed for ceftolozane/tazobactam (95.12%). All isolates of A. baumannii were 100% susceptible to colistin while susceptibility to tobramycin was (72.73%) and (63.16%) for both imipenem and ceftazidime.
The frequency and distribution of β-lactamase genes among Enterobacterales and P. aeruginosa
Genomic studies of 70 Enterobacterales (32 K. peumoniae, 22 E. coli, seven E. cloacae and nine others), revealed the presence of 157 different β-lactamases resistant genes representing all major classes; class A 71.42% (50/70), class B 24.29% (17/70), class C 25.71% (18/70) and class D 27.14% (19/70) with the overall dominance of the ESBLs blaTEM-OSBL. Combining microbiological and genetic characteristics, K. pneumoniae was more resistant with underlying class B MBLs blaNDM and class D OXA-48-like β-lactamases (specifically blaOXA-181 and blaOXA-232) when compared to E. coli that exhibit mainly class A β-lactamases (Table 3). Additionally, genomic studies of 49 carbapenem-resistant, P. aeruginosa isolates, Pseudomonas-derived cephalosporinases (PDCs) were the most prevalent resistance genes with predominance of blaPDC-3 (32.65%, 16/49), blaPDC-19A (10.2%, 5/49) and blaPDC-5 (8.16%, 4/49), while the MBL carbapenemase blaVIM-2 was detected in only four isolates (8.16%, 4/49), as shown in Table 4.
Table 3.
Organism name | No. of isolates | Class A β-lactamase | Class B β-lactamase | Class C β-lactamase | Class D β-lactamase | Total | |||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CTX-M-15 | CTX-M-1-240G | CTX-M-TYPE | CTX-M-14 | CTX-M-1-TYPE | CTX-M-9-240D | SHV-OSBL | SHV-31 | SHV-12 | SHV-ESBL | TEM-OSBL | KPC-2 | VEB-6 | NDM-1 | NDM-19 | NDM-5 | NDM-7 | NDM-TYPE | VIM-2 | VIM-4 | PDC-3 | PDC-19A | PDC-5 | PDC-1 | PDC-12 | PDC-14 | PDC-37 | PDC-35 | PDC-39 | PDC-TYPE | PDC-11 | PDC-117 | PDC-15 | PDC-16 | PDC-59 | PDC-60 | CMY-2-TYPE | CMY-TYPE | CMY-42 | CMY-59 | DHA-1 | DHA-TRUNC | DHA-TYPE | ACT-TYPE | MIR-TYPE | OXA-181 | OXA-232 | OXA-48 | OXA-TYPE | |||
Pseudomonas aeruginosa | 49 | 4 | 16 | 5 | 4 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 53 | ||||||||||||||||||||||||||||||||
Klebsiella pneumoniae | 32 | 16 | 4 | 1 | 1 | 1 | 26 | 3 | 2 | 21 | 1 | 5 | 1 | 3 | 1 | 1 | 2 | 13 | 2 | 104 | |||||||||||||||||||||||||||||||
Escherichia coli | 22 | 7 | 3 | 2 | 1 | 1 | 10 | 1 | 1 | 2 | 2 | 4 | 3 | 1 | 1 | 39 | |||||||||||||||||||||||||||||||||||
Enterobacter cloacae | 7 | 1 | 1 | 1 | 3 | 1 | 7 | ||||||||||||||||||||||||||||||||||||||||||||
Serratia marcescens | 3 | 1 | 1 | 2 | |||||||||||||||||||||||||||||||||||||||||||||||
Klebsiella variicola | 2 | 2 | 2 | ||||||||||||||||||||||||||||||||||||||||||||||||
Klebsiella aerogenes | 2 | 1 | 1 | ||||||||||||||||||||||||||||||||||||||||||||||||
Citrobacter freundii | 1 | 1 | 1 | ||||||||||||||||||||||||||||||||||||||||||||||||
Proteus mirabilis | 1 | 1 | 1 | ||||||||||||||||||||||||||||||||||||||||||||||||
Total | 119 | 23 | 7 | 3 | 1 | 1 | 1 | 26 | 3 | 1 | 2 | 31 | 1 | 1 | 8 | 1 | 3 | 3 | 2 | 4 | 1 | 16 | 5 | 4 | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 4 | 4 | 1 | 1 | 2 | 1 | 1 | 3 | 1 | 2 | 13 | 4 | 1 | 210 |
Subtotals | 101 | 22 | 67 | 20 | 210 |
Table 4.
Species | No. of isolates | Class A β-lactamase | Class B β-lactamase | Class C β-lactamase | Class D β-lactamase | |||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
CTX-M-15 | CTX-M-1-240G | CTX-M-TYPE | CTX-M-14 | CTX-M-1-TYPE | CTX-M-9-240D | SHV-OSBL | SHV-31 | SHV-ESBL | TEM-OSBL | KPC-2 | NDM-1 | NDM-19 | NDM-5 | NDM-7 | NDM-TYPE | VIM-2 | VIM-4 | PDC-3 | PDC-19A | PDC-5 | PDC-1 | PDC-12 | PDC-14 | PDC-37 | PDC-35 | PDC-39 | PDC-TYPE | PDC-11 | PDC-117 | PDC-16 | PDC-59 | PDC-60 | CMY-2-TYPE | CMY-42 | DHA-1 | DHA-TRUNC | ACT-TYPE | OXA-181 | OXA-232 | OXA-48 | OXA-TYPE | Total no. of genes | ||
Pseudomonas aeruginosa | 49 | 4 | 16 | 4 | 4 | 2 | 2 | 3 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 49 | ||||||||||||||||||||||||||
Klebsiella pneumoniae | 27 | 12 | 4 | 1 | 1 | 1 | 21 | 2 | 2 | 17 | 1 | 5 | 1 | 3 | 1 | 1 | 13 | 2 | 88 | |||||||||||||||||||||||||
Escherichia coli | 11 | 2 | 3 | 1 | 3 | 1 | 1 | 2 | 2 | 1 | 1 | 17 | ||||||||||||||||||||||||||||||||
Enterobacter cloacae | 4 | 1 | 1 | 1 | 1 | 4 | ||||||||||||||||||||||||||||||||||||||
Serratia marcescens | 3 | 1 | 1 | |||||||||||||||||||||||||||||||||||||||||
Klebsiella variicola | 2 | 2 | 2 | |||||||||||||||||||||||||||||||||||||||||
Klebsiella aerogenes | 1 | 1 | 1 | |||||||||||||||||||||||||||||||||||||||||
Total | 97 | 14 | 7 | 1 | 1 | 1 | 1 | 21 | 2 | 2 | 20 | 1 | 7 | 1 | 3 | 3 | 2 | 4 | 1 | 16 | 4 | 4 | 2 | 2 | 3 | 3 | 2 | 2 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 13 | 4 | 1 | 161 |
Subtotals | 71 | 21 | 50 | 19 | 161 |
Microbiological and genetic characteristics of carbapenem-resistant Enterobacterales and carbapenem-resistant P. aeruginosa
Microbiological and genetic characteristics of 48 studied CREs (27 K. pneumonias, 11 E. coli, four Enterobacter cloacae and six others) revealed prevalence of ertapenem resistance in 89.58% (43/48), imipenem at 87.5% (42/48) and meropenem at 72.91% (35/48) of clinical isolates with 70.83% (34/48) concordant resistance to all three agents (Table 5). Furthermore, genetic studies revealed extreme rarity of other types of carbapenem-resistance genes with predominance of class D (blaOXA-48-like type, specifically: 12 blaOXA-232, 4 blaOXA-48, 2 blaOXA-181, and 1 blaOXA-type) and class B MBL (7 blaNDM-1, 3 blaNDM-5, 3 blaNDM-7, 2 blaNDM-type, 1 blaNDM-19 and 1 blaVIM-4) (Table 4).
Table 5.
Species | Pseudomonas aeruginosa | Klebsiella pneumoniae | Escherichia coli | Enterobacter cloacae | Serratia marcescens | Klebsiella variicola | Klebsiella aerogenes | Total (%) |
---|---|---|---|---|---|---|---|---|
Gender | Number (%) | |||||||
Male | 37 (75.51) | 20 (74.07) | 5 (44.45) | 1 (25) | 3 (100) | 2 (100) | 1 (100) | 69 (71.13) |
Female | 12 (24.49) | 7 (25.93) | 6 (54.55) | 3 (75) | 0 | 0 | 0 | 28 (28.87) |
Location | ||||||||
In-patient | 27 (55.1) | 21 (77.78) | 8 (72.73) | 3 (75) | 0 | 0 | 0 | 59 (60.82) |
Intensive care unit | 22 (44.9) | 6 (22.22) | 3 (27.27) | 1 (25) | 3 (100) | 2 (100) | 1 (100) | 38 (39.18) |
Age | ||||||||
Paediatric < 14 years | 2 (4.08) | 1 (3.7) | 0 | 0 | 0 | 0 | 0 | 3 (3.09) |
Adult 14-65 years | 31 (63.27) | 15 (55.56) | 8 (72.73) | 3 (75) | 3 (100) | 2 (100) | 1 (100) | 63 (64.95) |
Geriatric > 65 | 16 (32.65) | 8 (29.63) | 3 (27.27) | 1 (25) | 0 | 0 | 0 | 28 (28.87) |
Site of isolation | ||||||||
RT | 36 (73.47) | 11 (40.74) | 0 | 1 (25) | 3 (100) | 1 (50) | 1 (100) | 53 (54.64) |
IA | 5 (10.2) | 5 (18.52) | 6 (54.55) | 1 (25) | 0 | 1 (50) | 0 | 18 (18.56) |
UT | 2 (4.08) | 7 (25.93) | 5 (45.45) | 2 (50) | 0 | 0 | 0 | 16 (16.49) |
BS | 6 (12.24) | 4 (14.81) | 0 | 0 | 0 | 0 | 0 | 10 (10.31) |
No. of isolates susceptible to | ||||||||
Aztreonam | 14 (28.57) | 9 (33.33) | 0 | 1 (25) | 3 (100) | 2 (100) | 1 (100) | |
Cefepime | 28 (57.14) | 5 (18.52) | 0 | 2 (50) | 2 (66.67) | 2 (100) | 1 (100) | |
Cefotaxime | NA | 10 (37.04) | 0 | 2 (50) | 3 (100) | 2 (100) | 1 (100) | |
Ceftazidime | 24 (48.98) | 6 (22.22) | 0 | 1 (25) | 3 (100) | 2 (100) | 0 | |
Ceftriaxone | NA | 5 (18.52) | 0 | 1 (25) | 2 (66.67) | 2 (100) | 0 | |
Colistin | 49 (100) | NA | NA | NA | NA | NA | NA | |
Meropenem | 8 (16.33) | 4 (14.81) | 3 (27.27) | 2 (50) | 2 (66.67) | 1 (50) | 1 (100) | |
Ertapenem | NA | 1 (3.7) | 0 | 1 (25) | 2 (66.67) | 0 | 1 (100) | |
Imipenem | 0 | 2 (7.41) | 3 (27.27) | 1 (25) | 0 | 0 | 0 | |
Ceftolozane/tazobactam | 41 (83.67) | 5 (18.52) | 1 (9.09) | 1 (25) | 2 (66.67) | 2 (100) | 1 (100) | |
Imipenem/relebactam | 35 (71.43) | 6 (22.22) | 5 (45.45) | 2 (50) | 0 | 0 | 1 (100) | |
Pipracillin/tazobactam | 19 (38.78) | 2 (7.41) | 0 | 1 (25) | 2 (66.67) | 0 | 1 (100) | |
Total (%) | 49 (100) | 27 (100) | 11 (100) | 4 (100) | 3 (100) | 2 (100) | 1 (100) | 97 (100) |
Microbiological evaluation of the 49 carbapenems-resistant P. aeruginosa isolates against imipenem and imipenem/relebactam, revealed that 14 isolates were resistant to both (concordant resistance), while 35 P. aeruginosa isolates were resistant to imipenem but susceptible to imipenem/relebactam (discordant resistant group) indicating relebactam restored 71.4% (35/49) of imipenem activity. Four of the concordant resistant isolates harboured class B MBL blaVIM2 while the rest were AmpC-type β-lactamases in the form of PDCs speared by blaPDC-3. Conversely, the discordant group although showed embedded PDCs including blaPDC-3 (eight isolates), were of diverse types including blaPDC-19A, blaPDC-1, blaPDC-5, blaPDC-14 and blaPDC-37 (five then three isolates each respectively). Furthermore, the eight P. aeruginosa isolates that were resistant to ceftolozane/tazobactam harboured the following β-lactamase genes: four blaVIM-2, four blaPDC-3, two blaPDC-5 and two blaPDC-35 Supplementary Table S2).
Discussion
The impact of AMR is a major global threat to humanity because of direct clinical as well as indirect economic and social consequences.12 To overcome AMR challenges, the widely adopted recommendation is to implement cornerstone concepts of basic and advanced surveillance studies to assess pathogens evolving microbiological characteristics as well as examine dynamic resistance mechanisms.18 Furthermore, following the implementation of conventional practices in modern healthcare such as regular bacterial phenotypic analysis, genotypic and molecular epidemiology has been advocated as crucial advanced concept to face unexpected challenges particularly at different regional healthcare settings.19
The SMART is an international research collaboration for the study of AMR in GNB focusing on four key infections: RTIs and UTIs together with IAIs and BSIs. The study started about two decades ago on a small scale then expanded as an ongoing global surveillance study.17 In the Middle East and Africa regions, 24 medical centres participated in the study detailed as follows (arranged alphabetically): Israel, Jordan, Kenya, Kuwait, Lebanon, Morocco, Qatar, Saudi Arabia, South Africa, Tunisia and the United Arab Emirates.
The results of surveillance of GNB from secondary and tertiary healthcare from Qatar with emphasis on the four specified sites of infections demonstrated dominance of four key pathogens namely, E coli, K. pneumoniae, P. aeruginosa and S. maltophiila, which are in line with published regional surveillance studies.6,20–23 Of note, E. coli remains the main pathogen for UTIs in contrast to K. pneuminae that were isolated mainly from RTIs followed by UTIs and IAIs but with established higher AMR (Table 2). This reflects that K. pneumoniae isolates from HAIs are mainly secondary to hospital or ventilation-associated pneumonia, which probably explains the high observed resistance rates. Similar epidemiological studies highlighted escalating MDR-GNB at critical care settings particularly rising trends of extremely-drug resistant K. pneumoniae.21,24,25
The presented results are the first comprehensive surveillance study in the country, and it reflects an alarmingly high-level AMR profile since for E. coli, the prevalence of phenotypic resistance pattern for ESBLs was higher than half of isolates (55.7%) while for K. pneumoniae was 39%. Almost a decade earlier, limited studies from Qatar at the existed but smaller healthcare settings focusing on 452 episodes of BSIs, established almost half ESBL prevalence (27.8% for E. coli and 17.9% for K. pneumoniae respectively) while a surveillance study of 629 consecutive Enterobacterales from critical care settings between 2012 and 2013 revealed the overall prevalence of 17.3%.26,27
In the Middle East region, focusing on GNB, the escalating problem of AMR is predominated by ESBL production with multifactorial explanations mainly from existing diverse population, frequent influx of seasonal international travellers together with the widely practised inappropriate and high antimicrobial consumption.28–30
Although E. coli exhibited higher ESBLs phenotypic resistance patterns compared to K. pneumoniae, detailed microbiological and genetic characteristics points towards the opposite where E. coli demonstrated lower-level resistance to carbapenems when compared to K. pneumoniae (meropenem resistance of 3.83% and 12.83%, respectively), which has not changed even for novel agents not currently available at the hospital formulary such as imipenem/relebactam (2.83% and 11.76%, respectively). Similarly, regarding newer agents of BLBLIs such as ceftazidime/avibactam and ceftolozane/tazobactam, in E. coli the overall resistance rates for the two agents were 3.65% and 10.05%, while for K. pneumoniae these were 5.98% and 14.97%, respectively. Again, this is showing rising trends for the two agents since between 2012 and 2013, when 109 ESBL producing Enterobacterales isolated from critical care were tested against ceftazidime/avibactam and ceftolozane/tazobactam, it demonstrated AMR rates of 0.9%.31
Distinctively when 49 carbapenem-resistant P. aeruginosa were tested against imipenem and imipenem/relebactam, all isolates were resistant to imipenem. Whereas relebactam restored in vitro imipemen activity in 71.4% (35/49) of isolates. Four of these isolates resistant to imipenem/relebactam harboured the MBL blaVIM-2 while the rest harboured different class C AmpC-type β-lactamases in the form of PDCs. Intriguingly, none of the resistant isolates harboured blaIMP as observed elsewhere.32 Comparatively, avibactam, which is a potent BLBLI capable of inhibiting class A, C and D β-lactamases but is overwhelmed by class B MBL such as blaNDM and blaVIM whereas the closely related relebactam has similar inhibition spectrum albeit with absent activity against class D OXA-type carbapenemases, demonstrated supplementary antimicrobial potency.33 Of note, for P. aeruginosa the classic pearl of wisdom that genotypic resistance patterns does not always equate phenotypic ones because there are other complex resistance mechanisms involving diverse membrane pathways such as the loss of porin channels and overproduction efflux pumps.34 While imipenem is more resistant to GNB ejecting efflux pumps when compared to meropenem, it remains susceptible to porin channel mutations that hinder its inward penetration conferring phenotypic resistance.33,35 In P. aeruginosa, the loss of OprD porin channels together with class C ESBLs and AmpC such as PDC is the hallmark of imipenem resistance.36
Among carbapenem-resistant P. aeruginosa, eight isolates that were resistant to ceftolozane/tazobactam harboured different β-lactamase genes: class B blaVIM-2; class C blaPDC-3, blaPDC-5 and blaPDC-35 and class B blaVIM-2 and blaPDC-35, which have been associated with high-level resistance to ceftolozane/tazobactam.37,38 When comparing discordant results of the in vitro activity for the novel BLBLIs for most Enterobacterales, it favours ceftazidime/avibactam over ceftolozane/tazobactam but not for P. aeruginosa where the latter demonstrated superior activity. Nevertheless, antimicrobials activity cannot be reliably extrapolated to clinical practice since evaluation for the two agents, demonstrated similar efficacy with no noticeable significant clinical differences.31,39–41
Genetic characterization of 70 Enterobacterales including 48 isolates that were CREs revealed the presence of all major β-lactamase classes with a predominance of blaCXM-15 ESBLs in conjunction with other historic resistant genes such as blaTEM and blaSHV distributed in K. pneumoniae and E. coli when compared to other GNB (Tables 3 and 4). The plasmid-mediated ESBL gene, blaCXM-15 has a global distribution with a direct link to advanced cephalosporins resistance being the most widely reported resistant gene from all global regions including the Middle East and Gulf countries.27,28,42,43 Noticeably, E. coli resistant genes were mainly class A ESBLs while K. pneumonia demonstrated more divergent pattern with the presence of a multitude of class D OXA-type ESBLs as well as carbapenemases such as blaNMD and blaOXA-48 and its closely related blaOXA-181 and blaOXA-232. These mutated resistant genes are derivatives from their parent carbapenemase blaOXA-48 with few point mutations.44 Locally, our PCR-based molecular techniques will report these different resistant genes grouped as blaOXA-48. Distinctively, among the 70 Enterobacterales and 48 CREs only a single K. pneumoniae isolate harboured blaKPC-2, which was probably imported as shown in similar local CREs studies.45 The plasmid-mediated KPCs serine carbapenemases are historically linked to the West, particularly North America and Southern Europe, although they have been reported in some other distant countries such as Israel and China but this has been extremely rare in our region.42,45,46 Furthermore, current molecular epidemiology, affirms reported and observed dominance of the carbapenemase blaOXA types and blaNDM in the region.28,45,47
Despite the diverse microbiological and genomic outcomes of the study, there are some noticeable limitations. The prospective study collected representative pathogens from specific infection sites that have changed over the study period, which might lessen the overall epidemiological accuracy. Furthermore, for microbiological and genetic testing, although the defined protocol was followed, it did change over time. For example, as novel antibiotics were introduced into clinical practice, they were evaluated but against fewer isolates. Therefore, a true comparison cannot be accurately reported. Last, the methods for genetic and molecular characterization of resistance followed the central study protocol, which is more detailed when compared to local practice. That might generate more elaborative results that are difficult to benchmark at local levels.
In conclusion, the SMART surveillance study from Qatar between 2017 and 2019 encompassed a sizeable collection of 748 isolates comprising 37 different GNB dominated by E. coli, K. pneumoniae, P. aeruginosa and S. maltophilia showing significant microbiological and genetic characteristics with a prevalence of divergent types of ARGs particularly blaCXM-15 whereas K. pneumonia isolates collected mainly from respiratory specimens were more resistant to existing as well as novel antimicrobials with a distinct overall dominance of blaOXA type and blaNDM carbapenemases.
Supplementary Material
Acknowledgements
We would like to express our gratitude to all involved staff at the division of microbiology of the department of laboratory medicine and pathology at Hamad Medical Corporation who were pivotal in adhering to the study protocol through timely processing of isolates, logging of details as well as facilitating collaborative links throughout the study period. The publication of the academic research is facilitated through collaboration and agreement with Qatar National Library (QNL).
Contributor Information
Mazen A Sid Ahmed, Philadelphia Department of Public Health, Laboratory Services, Philadelphia, USA.
Hawabibee Mahir Petkar, Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar.
Thoraya M Saleh, Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar.
Mohamed Albirair, Department of Global Health, University of Washington, Seattle, USA.
Lolita A Arisgado, Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar.
Faiha K Eltayeb, Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar.
Manal Mahmoud Hamed, Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar.
Muna A Al-Maslamani, Division of Infectious Diseases, Communicable Diseases Centre, Hamad Medical Corporation, Doha, Qatar.
Abdul Latif Al Khal, Division of Infectious Diseases, Communicable Diseases Centre, Hamad Medical Corporation, Doha, Qatar.
Hussam Alsoub, Division of Infectious Diseases, Communicable Diseases Centre, Hamad Medical Corporation, Doha, Qatar.
Emad Bashir Ibrahim, Division of Microbiology, Department of Laboratory Medicine and Pathology, Hamad Medical Corporation, Doha, Qatar; Biomedical Research Centre, Qatar University, Doha, Qatar.
Hamad Abdel Hadi, Division of Infectious Diseases, Communicable Diseases Centre, Hamad Medical Corporation, Doha, Qatar.
Funding
The SMART surveillance program is sponsored by MSD. We thank MSD and International Health Management Associates, S.A., Schaumburg, Illinois, USA (IHMA) for providing access to the database of the SMART epidemiological surveillance study for the purpose of analysis and evaluation. We must emphasize that there were no pharmaceutical influences during the interpretation of analysed results.
Transparency declarations
H.A.H. and E.B.I. disclose honorarium for collaboration in educational meetings sponsored by MSD. The rest of the authors have no conflicts of interest related to this academic publication.
Supplementary data
Tables S1 and S2 are available as Supplementary data at JAC-AMR Online.
References
- 1. Bassetti M, Poulakou G, Ruppe Eet al. . Antimicrobial resistance in the next 30 years, humankind, bugs and drugs: a visionary approach. Intensive Care Med 2017; 43: 1464–75. 10.1007/s00134-017-4878-x [DOI] [PubMed] [Google Scholar]
- 2. Livermore DM. Fourteen years in resistance. Int J Antimicrob Agents 2012; 39: 283–94. 10.1016/j.ijantimicag.2011.12.012 [DOI] [PubMed] [Google Scholar]
- 3. Naylor NR, Atun R, Zhu Net al. . Estimating the burden of antimicrobial resistance: a systematic literature review. Antimicrob Resist Infect Control 2018; 7: 58. 10.1186/s13756-018-0336-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Mazzariol A, Bazaj A, Cornaglia G. Multi-drug-resistant gram-negative bacteria causing urinary tract infections: a review. J Chemother 2017; 29: 2–9. 10.1080/1120009X.2017.1380395 [DOI] [PubMed] [Google Scholar]
- 5. Martin-Loeches I, Rodriguez AH, Torres A. New guidelines for hospital-acquired pneumonia/ventilator-associated pneumonia: USA vs. Europe. Curr Opin Crit Care 2018; 24: 347–52. 10.1097/MCC.0000000000000535 [DOI] [PubMed] [Google Scholar]
- 6. Hawser S, Hoban DJ, Badal REet al. . Epidemiology and antimicrobial susceptibility of gram-negative aerobic bacteria causing intra-abdominal infections during 2010-2011. J Chemother 2015; 27: 67–73. 10.1179/1973947814Y.0000000164 [DOI] [PubMed] [Google Scholar]
- 7. Bassetti M, Eckmann C, Giacobbe DRet al. . Post-operative abdominal infections: epidemiology, operational definitions, and outcomes. Intensive Care Med 2020; 46: 163–72. 10.1007/s00134-019-05841-5 [DOI] [PubMed] [Google Scholar]
- 8. Sartelli M, Coccolini F, Kluger Yet al. . WSES/GAIS/SIS-E/WSIS/AAST global clinical pathways for patients with intra-abdominal infections. World J Emerg Surg 2021; 16: 49. 10.1186/s13017-021-00387-8 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9. Kern WV, Rieg S. Burden of bacterial bloodstream infection-a brief update on epidemiology and significance of multidrug-resistant pathogens. Clin Microbiol Infect 2020; 26: 151–7. 10.1016/j.cmi.2019.10.031 [DOI] [PubMed] [Google Scholar]
- 10. Hay SI, Rao PC, Dolecek Cet al. . Measuring and mapping the global burden of antimicrobial resistance. BMC Med 2018; 16: 78. 10.1186/s12916-018-1073-z [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11. Cui X, Zhang H, Du H. Carbapenemases in enterobacteriaceae: detection and antimicrobial therapy. Front Microbiol 2019; 10: 1823. 10.3389/fmicb.2019.01823 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Eichenberger EM, Thaden JT. Epidemiology and mechanisms of resistance of extensively drug resistant gram-negative bacteria. Antibiotics (Basel) 2019; 8: 37. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13. Sid Ahmed MA, Khan FA, Sultan AAet al. . β-lactamase-mediated resistance in MDR-Pseudomonas aeruginosa from Qatar. Antimicrob Resist Infect Control 2020; 9: 170. 10.1186/s13756-020-00838-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Bonomo RA, Burd EM, Conly Jet al. . Carbapenemase-producing organisms: a global scourge. Clin Infect Dis 2018; 66: 1290–7. 10.1093/cid/cix893 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15. Inoue H. Strategic approach for combating antimicrobial resistance (AMR). Glob Health Med 2019; 1: 61–4. 10.35772/ghm.2019.01026 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. CLSI . Performance Standards for Antimicrobial Susceptibility Testing. 30th edn. CLSI Supplement M100. Clinical Laboratory Standards Institute, 2020 [cited 2020 Jan 21]. Available from: https://www.nih.org.pk/wp-content/uploads/2021/02/CLSI-2020.pdf.
- 17. Morrissey I, Hackel M, Badal Ret al. . A review of ten years of the study for monitoring antimicrobial resistance trends (SMART) from 2002 to 2011. Pharmaceuticals (Basel) 2013; 6: 1335–46. 10.3390/ph6111335 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. Tacconelli E, Sifakis F, Harbarth Set al. . Surveillance for control of antimicrobial resistance. Lancet Infect Dis 2018; 18: e99–e106. 10.1016/S1473-3099(17)30485-1 [DOI] [PubMed] [Google Scholar]
- 19. Tacconelli E, Cataldo MA, Dancer SJet al. . ESCMID Guidelines for the management of the infection control measures to reduce transmission of multidrug-resistant gram-negative bacteria in hospitalized patients. Clin Microbiol Infect 2014; 20Suppl 1: 1–55. 10.1111/1469-0691.12427 [DOI] [PubMed] [Google Scholar]
- 20. Gales AC, Castanheira M, Jones RNet al. . Antimicrobial resistance among gram-negative bacilli isolated from Latin America: results from SENTRY antimicrobial surveillance program (Latin America, 2008–2010). Diagn Microbiol Infect Dis 2012; 73: 354–60. 10.1016/j.diagmicrobio.2012.04.007 [DOI] [PubMed] [Google Scholar]
- 21. Morris S, Cerceo E. Trends, epidemiology, and management of multi-drug resistant gram-negative bacterial infections in the hospitalized setting. Antibiotics (Basel, Switzerland) 2020; 9: 196. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22. Hawser SP, Bouchillon SK, Hoban DJet al. . Incidence and antimicrobial susceptibility of Escherichia coli and Klebsiella pneumoniae with extended-spectrum beta-lactamases in community- and hospital-associated intra-abdominal infections in Europe: results of the 2008 Study for Monitoring Antimicrobial Resistance Trends (SMART). Antimicrob Agents Chemother 2010; 54: 3043–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Sid Ahmed MA, Abdel Hadi H, Abu Jarir Set al. . Prevalence and microbiological and genetic characteristics of multidrug-resistant Pseudomonas aeruginosa over three years in Qatar. Antimicrob Steward Healthc Epidemiol 2022; 2: e96. 10.1017/ash.2022.226 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24. Jean SS, Chang YC, Lin WCet al. . Epidemiology, treatment, and prevention of nosocomial bacterial pneumonia. J Clin Med 2020; 9: 275. 10.3390/jcm9010275 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25. Teerawattanapong N, Kengkla K, Dilokthornsakul Pet al. . Prevention and control of multidrug-resistant Gram-negative bacteria in adult intensive care units: a systematic review and network meta-analysis. Clin Infect Dis 2017; 64: S51–60. 10.1093/cid/cix112 [DOI] [PubMed] [Google Scholar]
- 26. Khan FY, Elshafie SS, Almaslamani Met al. . Epidemiology of bacteraemia in Hamad General Hospital, Qatar: a one year hospital-based study. Travel Med Infect Dis 2010; 8: 377–87. 10.1016/j.tmaid.2010.10.004 [DOI] [PubMed] [Google Scholar]
- 27. Sid Ahmed MA, Bansal D, Acharya Aet al. . Antimicrobial susceptibility and molecular epidemiology of extended-spectrum beta-lactamase-producing Enterobacteriaceae from intensive care units at Hamad medical corporation, Qatar. Antimicrob Resist Infect Control 2016; 5: 4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28. Dandachi I, Chaddad A, Hanna Jet al. . Understanding the epidemiology of multi-drug resistant Gram-negative bacilli in the Middle East using a one health approach. Front Microbiol 2019; 10: 1941. 10.3389/fmicb.2019.01941 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29. Zowawi HM, Balkhy HH, Walsh TRet al. . β-Lactamase production in key gram-negative pathogen isolates from the Arabian Peninsula. Clin Microbiol Rev 2013; 26: 361–80. 10.1128/CMR.00096-12 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30. Sid Ahmed MA, Abdel Hadi H, Abu Jarir Set al. . Impact of an antimicrobial stewardship programme on antimicrobial utilization and the prevalence of MDR Pseudomonas aeruginosa in an acute care hospital in Qatar. JAC-Antimicrobial Resistance 2020; 2: dlaa050. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31. Ahmed MAS, Ibrahim EB, Hamid JMet al. . Evaluation of in vitro activity of ceftazidime/avibactam and ceftolozane/tazobactam against ESBL-producing enterobacterales isolated from intensive care units from Qatar. Oman Med J 2022; 37: e422. 10.5001/omj.2022.89 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32. Tenover FC, Nicolau DP, Gill CM. Carbapenemase-producing pseudomonas aeruginosa—an emerging challenge. Emerg Microbes Infect 2022; 11: 811–4. 10.1080/22221751.2022.2048972 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33. Wright H, Bonomo RA, Paterson DL. New agents for the treatment of infections with gram-negative bacteria: restoring the miracle or false dawn? Clin Microbiol Infect 2017; 23: 704–12. 10.1016/j.cmi.2017.09.001 [DOI] [PubMed] [Google Scholar]
- 34. Livermore DM. Multiple mechanisms of antimicrobial resistance in Pseudomonas aeruginosa: our worst nightmare? Clin Infect Dis 2002; 34: 634–40. 10.1086/338782 [DOI] [PubMed] [Google Scholar]
- 35. Horcajada JP, Montero M, Oliver Aet al. . Epidemiology and treatment of multidrug-resistant and extensively drug-resistant Pseudomonas aeruginosa infections. Clin Microbiol Rev 2019; 32: e00031-19. 10.1128/CMR.00031-19 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36. Codjoe FS, Donkor ES. Carbapenem resistance: a review. Med Sci (Basel) 2017; 6: 1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37. Rotondo CM, Wright GD. Inhibitors of metallo-β-lactamases. Curr Opin Microbiol 2017; 39: 96–105. 10.1016/j.mib.2017.10.026 [DOI] [PubMed] [Google Scholar]
- 38. Sid Ahmed MA, Khan FA, Hadi HAet al. . Association of bla(VIM-2), bla(PDC-35), bla(OXA-10, ) bla(OXA-488) and bla(VEB-9) β-lactamase genes with resistance to ceftazidime-avibactam and ceftolozane-tazobactam in multidrug-resistant Pseudomonas aeruginosa. Antibiotics (Basel) 2022; 11: 130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39. Wilson GM, Fitzpatrick M, Walding Ket al. . Meta-analysis of clinical outcomes using ceftazidime/avibactam, ceftolozane/tazobactam, and meropenem/vaborbactam for the treatment of multidrug-resistant gram-negative infections. Open Forum Infect Dis 2021; 8: ofaa651–ofaa. 10.1093/ofid/ofaa651 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40. Nguyen CP, Dan Do TN, Bruggemann Ret al. . Clinical cure rate and cost-effectiveness of carbapenem-sparing beta-lactams vs. Meropenem for Gram-negative infections: a systematic review, meta-analysis, and cost-effectiveness analysis. Int J Antimicrob Agents 2019; 54: 790–7. 10.1016/j.ijantimicag.2019.07.003 [DOI] [PubMed] [Google Scholar]
- 41. Sid Ahmed MA, Abdel Hadi H, Hassan AAIet al. . Evaluation of in vitro activity of ceftazidime/avibactam and ceftolozane/tazobactam against MDR Pseudomonas aeruginosa isolates from Qatar. J Antimicrob Chemother 2019; 74: 3497–504. 10.1093/jac/dkz379 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42. Bush K, Bradford PA. Epidemiology of β-lactamase-producing pathogens. Clin Microbiol Rev 2020; 33: e00047-19. 10.1128/CMR.00047-19 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 43. Perez-Lopez A, Sundararaju S, Al-Mana Het al. . Molecular characterization of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae among the pediatric population in Qatar. Front Microbiol 2020; 11: 581711. 10.3389/fmicb.2020.581711 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44. Shu L, Dong N, Lu Jet al. . Emergence of OXA-232 carbapenemase-producing Klebsiella pneumoniae that carries a pLVPK-like virulence plasmid among elderly patients in China. Antimicrob Agents Chemother 2019; 63: e02246-18. 10.1128/AAC.02246-18 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45. Abid FB, Tsui CKM, Doi Yet al. . Molecular characterization of clinical carbapenem-resistant enterobacterales from Qatar. Eur J Clin Microbiol Infect Dis 2021; 40: 1779–85. 10.1007/s10096-021-04185-7 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46. Higgins PG, Hagen RM, Kreikemeyer Bet al. . Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii isolates from Northern Africa and the Middle East. Antibiotics (Basel) 2021; 10: 291. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 47. Alotaibi F. Carbapenem-resistant enterobacteriaceae: an update narrative review from Saudi Arabia. J Infect Public Health 2019; 12: 465–71. 10.1016/j.jiph.2019.03.024 [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.