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Archives of Industrial Hygiene and Toxicology logoLink to Archives of Industrial Hygiene and Toxicology
. 2021 Dec 30;72(4):305–314. doi: 10.2478/aiht-2021-72-3560

Detection and characterisation of extended-spectrum and plasmid-mediated AmpC β-lactamase produced by Escherichia coli isolates found at poultry farms in Bosnia and Herzegovina

Detekcija i karakterizacija beta laktamaza proširenog spektra i plazmidnih AmpC beta-laktamaza u izolatima Escherichia coli s peradarskih farmi u Bosni i Hercegovini

Majda Fetahagić 1, Amir Ibrahimagić 2,, Selma Uzunović 3, Nataša Beader 4,5, Vesna Elveđi-Gašparović 4,5, Josefa Luxner 6, Muhamed Gladan 1, Branka Bedenić 4,5
PMCID: PMC8785107  PMID: 34985844

Abstract

Extended-spectrum β-lactamases (ESBLs) hydrolyse extended-spectrum cephalosporins (ESC) and aztreonam. As ESBL-producing organisms have been identified in food producing animals, the aim of our study was to detect and analyse such Escherichia coli isolates from poultry. Antibiotic susceptibility of the isolates was determined with disk-diffusion and broth microdilution methods. ESBLs were detected with the double-disk synergy and inhibitor-based test with clavulanic acid. The transferability of cefotaxime resistance was determined with conjugation experiments, and genes encoding ESBLs, plasmid-mediated AmpC β-lactamases, and quinolone resistance determinants identified by polymerase chain reaction. The study included 108 faecal samples (cloacal swabs) from 25 different poultry farms in the Zenica-Doboj Canton, Bosnia and Herzegovina. Of these, 75 (69.4 %) were positive for E. coli, of which 27 were resistant to cefotaxime, amoxicillin, cefazoline, and cefriaxone, and susceptible to imipenem, meropenem, ertapenem, and amikacin. All 27 cefotaxime-resistant isolates were positive in double-disk synergy and combined disk tests. Eighteen isolates transferred cefotaxime resistance to E. coli recipient. Twenty-one isolates were positive for the blaCTX-M-1 cluster genes and seven for blaCTX-M-15. Fourteen were positive for the blaTEM genes. The most frequent plasmid incompatibility group was IncFIB, whereas IncFIA and Inc HI1 were present in only a few isolates. Two different sequence types (STs) were identified: ST117 and ST155. The emergence of ESBL-producing E. coli in farm animals presents a public health threat, as they can colonise the intestine and cause infections in humans.

KEY WORDS: antimicrobial resistance, chicken, CTX-M, ESBL, public health, ST117, ST155


Extended-spectrum beta-lactamases (ESBLs) produced by bacteria raise public health concern as they mediate the hydrolysis of important antibiotics, including cephalosporins, and aztreonam (1). Recent reports of ESBL-producing bacteria include Klebsiella pneumoniae, Escherichia coli, other Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa (24). Of the three major ESBL families, CTX-M β-lactamases are the most common and, unlike the TEM and SHV families found in hospital pathogens, prevail in community acquired infections (5, 6) and have become a global problem, CTX-M-15 in particular (7).

As ESBL-encoding genes are located on transferable plasmids, other bacterial species can also get them and become resistant to antibiotics to which they are otherwise susceptible. They are most often found in K. pneumoniae (40 %) and E. coli (4 %), but their prevalence depends on local epidemiology (8, 9). Unlike ESBLs, plasmid-mediated AmpC β-lactamases are derived from chromosomal β-lactamases of the Enterobacter, Serratia, Citrobacter, Pseudomonas, and Acinetobacter genera by the escape of the chromosomal gene to the plasmid. They hydrolyse extended-spectrum cephalosporins (ESC), monobactams, and cephamycins and are not susceptible to clavulanic acid, sulbactam, or tazobactam (10).

However, what prompted our research had been recent reports of the global spread of ESBL-producing E. coli among livestock (including poultry and pigs) with positive findings of CTX-M-9, 14, 15, 27, and 32 β-lactamases (1115). Farm animals were also found to harbour inhibitor-resistant TEM (IRT) β-lactamases IRT-2, 6, and 15 (16).

Considering that reports from Eastern Europe are scarce and there are none from Bosnia and Herzegovina, we carried out this study with the aim to identify and analyse E. coli isolates capable of producing ESBLs in poultry raised in our country, as these bacteria can colonise human intestines, especially if the meat is undercooked.

MATERIAL AND METHODS

Bacterial isolates

Between September and October 2019, we took 108 faecal samples (cloacal swabs) from 25 poultry farms located in the Zenica-Doboj Canton (Bosnia and Herzegovina) for diagnostic laboratory investigations, including bacterial isolation and identification. Samples were cultured on blood and MacConkey agar supplemented with 3 mg/L of cefotaxime (Oxoid, Besingstoke, UK) to detect cefotaxime-resistant isolates (17). Using the standard microbiological methods and observing colony morphology and biochemical reactions with indole, Kligler Iron Agar (KIA), citrate agar, phenyl-alanine agar, and urease agar (18) all 27 non-copy isolates were identified as E. coli. They were further evaluated at the University Hospital Centre Zagreb, Department for Clinical and Molecular Microbiology using molecular methods.

Antimicrobial susceptibility testing

Antimicrobial susceptibility of the 27 cefotaxime-resistant E. coli isolates was established with the Kirby-Bauer disk-diffusion and broth microdilution methods according to the Clinical and Laboratory Standards Institute (CLSI) recommendations (19). The same antibiotics were used for both disk-diffusion and broth dilution test, except that some antibiotics such as sulphamethoxazole/trimethoprim, ertapenem, and cefoxitin were tested only with the disk method.

Minimum inhibitory concentrations (MICs) of amoxicillin alone and in combination with clavulanate, piperacillin/tazobactam, cefazoline, extended-spectrum cephalosporins (ESCs; ceftazidime, cefotaxime, and ceftriaxone), cefepime, imipenem, meropenem, gentamicin, or ciprofloxacin were determined with the broth dilution test. The range of tested concentrations was 0.06 to 128 μg/mL. E. coli ATCC 25922 and K. pneumoniae ATCC 700603 were used as quality control strains.

ESBLs were screened for using the double-disk synergy test (DDST) as described elsewhere (20). Briefly, a disk containing amoxicillin with clavulanic acid is placed in the centre of the plate, and disks containing ceftazidime, cefotaxime, ceftriaxone, and cefepime 25 mm apart from the central disk. The test is considered positive if, after overnight incubation at 37 °C, the inhibition zone around cephalosporin disks extends towards the central disk with clavulanic acid.

ESBL production was confirmed with the combined disk test with cephalosporins and clavulanic acid according to CLSI (19). Briefly, the overnight broth culture of the test isolate was diluted to McFarland 0.5 turbidity and swabbed on Mueller-Hinton agar. Disks containing ceftazidime (30 μg), cefotaxime (30 μg), ceftriaxone (30 μg), and cefepime (30 μg) were placed on the surface of the agar plate, and 10 μL of clavulanic acid (10 g/L) was dropped on the disks. The control disks contained the same antibiotics but without clavulanate. ESBL production was confirmed if the inhibition zones around ceftazidime, cefotaxime, ceftriaxone, and cefepime disks with clavulanic acid were at least 5 mm wider in diameter than around control disks without it.

Cefotaxime hydrolysis by ESBL was tested with the cephalosporin inactivation method (CIM) as originally described for carbapenem inactivation testing (21). Briefly, disks containing cefotaxime (10 mg) were placed in a heavy suspension of the test strains and the samples were incubated at 37 °C for 2 h. Disks were then taken out and placed on the Mueller-Hinton agar previously inoculated with E. coli ATCC 25922 susceptible to cefotaxime. The test was considered positive if there was no inhibition zone, if it was <14 mm in diameter, or if the colonies grew within the inhibition zone.

Four cefoxitin-resistant isolates were tested for plasmid-mediated AmpC β-lactamases using the combined disk test with cephalosporin and 3-aminophenylboronic acid (PBA) disks as described elsewhere (22). Briefly, overnight broth culture of the test isolate was diluted to the 0.5 McFarland turbidity and swabbed on Mueller-Hinton agar. Disks containing ceftazidime (30 μg), cefotaxime (30 μg), ceftriaxone (30 μg), and cefepime (30 μg) were placed on the surface of the agar plate and 10 μL of pAmpC-inhibiting PBA was dropped on the disks. The control disks contained the same antibiotics without PBA. The test was considered positive if the inhibition zone around PBA was at least 5 mm longer in diameter than the respective control disk.

Conjugation

The conjugation experiment was performed by “mating” the experimental E. coli isolates (donors) with the J65 strain resistant to sodium azide (recipient) according to Elwel and Falkow (23). Overnight broth cultures of donor and recipient strains were mixed in the ratio of 1:2 v/v in Brainheart infusion broth (BHI) and incubated without shaking at 37 °C for another night. Mating mixtures were then placed on combined plates containing cefotaxime (2 mg/L) or ciprofloxacin (1 mg/L) to inhibit the growth of recipient strain and sodium azide (100 mg/L) to inhibit the donor strains. The frequency of conjugation was determined relative to the number of donor cells. The co-transfer of resistance to non β-lactam antibiotics such as tetracycline, chloramphenicol, sulphamethoxazole/trimethoprim and gentamicin was tested as well.

Molecular detection of resistance genes

The DNA was extracted using the heat lysis protocol as described elsewhere (24). Briefly a heavy suspension of the tested strains prepared in 500 μL of ultrapure water was boiled at 95 °C for 15 min and then spun at 6720 g for 2 min. The obtained clear supernatant was used as template DNA for polymerase chain reaction (PCR).

Genes coding for broad and extended-spectrum β-lactamases (blaSHV, blaTEM, blaCTX-M, and blaPER-1), plasmid-mediated AmpC β-lactamases, and quinolone resistance (qnr) were detected as described earlier (2529). Table 1 shows the primers used in this study. The CTX-M β-lactamase cluster was detected with multiplex PCR including five primer pairs: CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9, and CTX-M-25. For genes coding for CTX-M-8 and CTX-M-25 clusters we used the common reverse primer (30). Amplicons were visualised after electrophoresis in 1 % agarose by staining it with ethidium bromide (Sigma Aldrich, St. Louis, MO, USA). A 100 bp ladder was used as standard to determine the size of the products. The expected size of the amplicons is shown in Table 1. Amplicons were purified using the QIAquick PCR purification kit (Qiagen, Hilden, Germany) according to manufacturer’s instructions (31). DNA was sequenced on both strands by the Eurofins Genomics (Ebersberg, Germany) using the same primers that generated amplified products.

Table 1.

Primers for ESBL detection with PCR

Primer designation Target gene Sequence Amplicon size Ref.
OT 3 TEM 5’-ATG-AGT-ATT- CAA-CAT-TTC-CG-3’ 850 25
OT 4 TEM 5’-CCA-ATG-CTT-AAT-CAG-TGA-GG-3’ 850 25
SHV-F SHV 5’-TTC-GCC-TGT-GTA-TTA-TCT-CCC-3 1000 26
SHV-R SHV 5’-TTA-GCG-TTG-CCA-GTG-YTC-GAT-3’ 1000 26
MA-1 CTX-M 5’-SCS-ATG-TGC-AGY-ACC-AGT-AA-3’ 550 27
MA-2 CTX-M 5’-CGC-CRA-TAT-GRT-TGG-TGG-TG-3’ 550 27
M1-F CTX-M-1 cluster 5’-AAA-AAT-CAC-TGC-GCC-AGT--TC-3’ 415 30
M1-R CTX-M-1 cluster 5’-TTG-GTG-ACG-ATT-TTA-GCC-GC-3’ 415 30
M2-F CTX-M-2 cluster 5’-CGA-CGC-TAC-CCC-TGC-TAT-T--3’ 552 30
M2-R CTX-M-2 cluster 5’-CCA-GCG-TCA-GAT-TTT-TCA-GG-3’ 552 30
M8-F CTX-M-8 cluster 5-TCG-CGT-TAA-GCG-GAT-GAT-GC 666 30
M9-F CTX-M-9 cluster 5’-CAA-AGA-GAG-TGC-AAC-GGA-TG 205 30
M9-R CTX-M-9 cluster 5’ATT-GGA-AAG-CGT-TCA-TCA-CC 205 30
M25-F CTX-M-25 cluster 5’GCA-CGA-TGA-CAT-TCG-GG 327 30
M9/M25-R CTX-M-8/25 clusters 5’AAC-CCA-CGA-TGT-GGG-TAG-C 30
IS26-F IS26 5’-AAA-AAT-GAT-TGA-AAG-GTG-GT-3’ 31
IS26-R IS26 5’-ATT-CGG-CAA-GTT-TTT-GCT-GT-3 31
ISEcp-F ISEcp 5’-AAA-AAT-GAT-TGA-AAG-GTG-GT-3’ 31
ISEcp-R ISEcp 5’-AAT-ACT-ACC-TTG-CTT-TCT-GA-3’ 31
QNR A-F QNR A 5’-ATT-TCT-CAC-GCC-AGG-ATT-TG-3’ 29
QNR A-R QNR A 5’-GAT-CGG-CAA-AGG-TTA-GGT-CA-3’ 29
QNR B-F QNR B 5’-GAT-CGT-GAA-AGC-CAG-AAA-GG 29
QNR B-R QNR B 5’-ACG-ATG-CCT-GGT-AGT-TGT-CC 29
QNR S-F QNR S 5’-ACG-ACA-TTC-GTC-AAC-TGC-AA 29
QNR S-R QNR S 5’-TAA-ATT-GGC-ACC-CTG-TAG-GC 29

The genetic context of blaCTX-M genes was determined by PCR mapping with forward primer for insertion sequences ISEcp1 and IS26 combined with primer MA-3 (universal reverse primer for blaCTX-M genes) (32). Positive control strains producing TEM-1, TEM-2, SHV-1, and SHV-2 were kindly provided by Professor Adolf Bauernfeind (Max von Pettenkofer Institute, Munich, Germany), and those producing CTX-M-3 and CTX-M-15 by Professor Neil Woodford (Health Protection Agency, London, UK).

Characterisation of plasmids

Plasmids were extracted with the Qiagen Plasmid Mini Kit according to the manufacturer’s instructions (33). To identify plasmids coding for ESBLs we relied on PCR-based replicon typing (PBRT) as described by Carattoli et al. (34) updated to identify and distinguish between IncL and IncM plasmids (35). Five multiplex (I, II, III, IV, and V) and two simplex (B and K) reactions were used to determine the incompatibility group based on the size of the product after gel electrophoresis and staining with ethidium bromide. Plasmid extractions from donor and transconjugant strains were subjected to PCR for detection of blaESBL genes in order to determine their location. Positive control strains were kindly provided by Dr Alessandra Carattoli (Istituto Superiore di Sanità, Rome, Italy).

Genotyping

Two randomly selected isolates were genotyped with multilocus sequence typing (MLST) as described by Wirth et al. (36). Seven housekeeping genes were amplified with PCR, namely adk, fumC, gyrB, icd, mdh, purA, and recA (37).

PCR products were detected with agarose gel electrophoresis and then purified and sequenced using the Eurofins service. The obtained sequences were deposited by above mentioned online service to obtain sequence types (STs).

RESULTS

Of the 108 cloacal swabs taken from poultry farms, 75 (69.4 %) had E. coli, of which 27 were cefotaxime-resistant. All 27 cefotaxime-resistant E. coli isolates were also uniformly resistant to amoxicillin, cefazoline, cefotaxime, and cefriaxone. High resistance rates were observed for cefuroxime (n=26), moderate for ciprofloxacin (n=8), and low for ceftazidime (n=4) and cefepime (n=1). Only two isolates were resistant to gentamicin. There was no resistance to imipenem and meropenem (Table 2).

Table 2.

Antibiotic minimum inhibitory concentrations, genes, plasmids, and genotyping of E. coli isolates from poultry farms in Bosnia and Herzegovina

No. Protocol number Minimum inhibitory concentrations (mg/L) and resistance breakpoint (≥) of antibiotics Genes, plasmids, and genotypes
AMX >32 AMC 128/16 TZP >128/4 CZ >4 CXM >32 CAZ >32 CTX >4 CRO >4 FEP >32 IMI >4 MEM >4 GM >16 CIP >4 ESBL bla genes PBI and ST
1 31 >128 8 32 >128 >128 64 >128 >128 64 0.5 0.25 >128 >128 + TEM, CTX-M-15 FIA
2 32 >128 32 8 >128 32 0.5 32 32 0.25 0.12 0.06 2 0.25 + ND ND
3 35 >128 1 2 >128 >128 2 >128 >128 0.5 0.06 0.06 0.5 2 + CTX-M-1 cluster FIA
4 36 >128 4 8 >128 >128 2 64 64 1 0.06 0.06 1 0.25 + CTX-M-1 cluster FIB, ST 117
5 37 >128 8 16 >128 >128 1 >128 64 1 0.12 0.06 1 0.5 + ND FIB
6 39 >128 4 8 >128 >128 2 64 64 0.5 0.12 0.12 2 0.12 + TEM, CTX-M-15 ND
7 40 >128 8 4 >128 >128 0.5 >128 >128 0.5 0.06 0.06 1 0.25 + ND ND
8 41 >128 1 4 >128 32 1 64 32 1 0.25 0.12 2 0.25 + CTX-M-1 cluster ND
9 43 >128 16 16 >128 >128 8 >128 >128 1 0.25 0.06 4 0.06 + ND ND
10 44 >128 32 16 >128 >128 32 >128 >128 2 0.06 0.06 0.5 0.12 + ND FIB
11 45 >128 16 16 >128 >128 1 >128 >128 0.5 0.5 0.06 2 0.12 + CTX-M-1 cluster ND
12 46 >128 8 4 >128 >128 2 >128 64 1 0.12 0.12 4 0.06 + TEM, CTX-M-1 cluster ND
13 47 >128 8 8 >128 >128 16 64 64 1 0.06 0.06 1 0.25 + TEM, CTX-M-1 cluster I1
14 49 >128 4 16 >128 >128 4 >128 >128 16 0.25 0.06 0,5 16 + TEM, CTX-M-1 cluster I1
15 50 >128 8 16 >128 >128 8 >128 >128 16 0.25 0.12 2 64 + TEM, CTX-M-15 I1, FIB
16 51 >128 2 4 >128 >128 0.5 >128 >128 0.5 0.12 0.12 2 0.25 + ND FIB
17 53 >128 2 4 >128 >128 8 >128 >128 8 0.25 0.06 1 0.25 + TEM, CTX-M-15 ND
18 54 >128 4 2 >128 >128 1 >128 64 0.5 0.5 0.06 0.5 0.12 + TEM, CTX-M-15 I1, FIB
19 55 >128 1 2 >128 >128 1 >128 >128 2 0.06 0.06 0.5 0.5 + TEM, CTX-M-1 cluster I1
20 56 >128 4 32 >128 >128 16 >128 >128 16 0.5 0.25 2 4 + TEM, CTX-M-1 cluster I1, HI1
21 58 >128 2 2 >128 >128 2 >128 >128 8 0.25 0.25 1 0.25 + CTX-M-1 cluster ND
22 59 >128 32 4 >128 64 0.5 >128 64 0.5 0.12 0.12 16 32 + TEM, CTX-M-1 cluster I1
23 60 >128 32 16 >128 >128 16 >128 32 2 0.5 0.25 1 32 + CTX-M-1 cluster I1, HI1, ST155
24 64 >128 32 64 >128 16 >128 >128 32 4 1 0.5 2 >128 + TEM, CTX-M,-1 cluster I1, FIB
25 65 >128 4 8 >128 >128 2 64 32 2 0.06 0.06 0.25 0.12 + TEM, CTX-M-1 cluster I1
26 66 >128 32 4 >128 32 >128 >128 16 1 0.06 0.06 0.5 64 + TEM, CTX-M-1 cluster FIB
27 69 >128 8 2 >128 >128 2 >128 >128 2 0.25 0.12 0.25 0.12 + CTX-M-15 FIA

AMX – amoxicillin; AMC – amoxicillin/clavulanic; acid; TZP – piperacillin/tazobactam; CZ – cefazolin; CXM – cefuroxime; CAZ – ceftazidime; CTX – cefotaxime; CRO – ceftriaxone; FEP – cefepime; IMI – imipenem; MEM – meropenem; GM – gentamicin; CIP – ciprofloxacin; ESBL – inhibitor based test with clavulanic acid for detection of extended-spectrum beta-lactamases; BL – beta–lactamase content; PBI – plasmid incompatibility group, ST – sequence type; ND – not detected

Cefoxitin, amikacin, ertapenem, and cotrimoxazole showed good activity with the disk-diffusion method (Table 3).

Table 3.

Antibiotic susceptibility of E. coli isolates established with the disk-diffusion test

Isolate No. Protocol number Disk-diffusion method
FOX AMI ERT SXT
1 31 S S S R
2 32 S S S S
3 35 S S S S
4 36 S S S S
5 37 S S S S
6 39 S S S S
7 40 S S S S
8 41 S S S S
9 43 S S S S
10 44 S S S S
11 45 S S S S
12 46 S S S S
13 47 S S S S
14 49 S S S S
15 50 S S S S
16 51 S S S S
17 53 S S S S
18 54 S S S S
19 55 S S S S
20 56 S S S R
21 58 R S S S
22 59 S S S S
23 60 R S S S
24 64 R S S S
25 65 S S S S
26 66 R S S S
27 69 S S S S

AMI – amikacin; ERT – ertapenem; FOX – cefoxitin; R – resistant; S – susceptible; SXT – sulphametoxazole-trimethoprim

All cefotaxime-resistant isolates tested positive for ESBLs with both the DDST (Figure 1) and combined disk test (Figure 2), with the enlargement of the inhibition zones around cephalosporins ranging from 5 to 22 mm in the presence of clavulanic acid. The CIM test (Figure 3) confirmed production of ESBL in all tested organisms, with no inhibition zone around cefotaxime disks. Four isolates demonstrated resistance to cefoxitin and were positive in the combined disk test with cloxacillin, with inhibition zones ranging from 10 to 14 mm, which pointed to pAmpC (Figure 4).

Figure 1.

Figure 1

Phenotypic detection of ESBL producers with DDST. The elliptical inhibitory zone between cephalosporins and clavulanic acid (augmentin) indicates an ESBL-producing organism. AUG – augmentin; CAZ – ceftazidime; CPM – cefepime; CRO – ceftriaxone; CTX – cefotaxime

Figure 2.

Figure 2

Phenotypic detection of ESBL-producing organisms with the combined disk test. Positive results are those with visible inhibition zones (>5 mm in diameter) around CAZ, CTX, and CRO disks in combination with clavulanate vs those without clavulanate. CAZ – ceftazidime; CRO – ceftriaxone; CTX – cefotaxime

Figure 3.

Figure 3

Cephalosporin inactivation method (CIM) with the control E. coli ATCC 25922 strain. Left: cefotaxime disk (10 mg) was placed in a heavy suspension of test strains. Right: cefotaxime disk on the surface of the plate as negative control

Figure 4.

Figure 4

Combined disk test for the detection of plasmid-mediated AmpC β-lactamases with the cefotaxime disk alone (left) and in combination with 3-aminophenylboronic acid (right)

Conjugation

Eighteen of the 27 isolates transferred cefotaxime resistance to the E. coli recipient strain with the frequency ranging from 5.6×10-6 to 5×10-4. Alongside cefotaxime, tetracycline resistance was cotransferred from six, cotrimoxazole from two, and gentamicin resistance from one isolate (Table 4). Ciprofloxacin resistance was not transferred from any of the tested strains.

Table 4.

Conjugation frequency and cotransferred resistance markers

Isolate No. Protocol number Frequency Cotransferred resistance markers
1 31 8×10-5 Gm, Smx
2 32 5.5×10-4
3 35 3.5×10-5
4 36 1.2×10-4
5 37 1.4×10-5
6 39 8.4×10-5
7 40 4.5×10-5
8 41 0
9 43 10-4 Tet
10 44 5×10-4 Tet
11 45 1.6×10-6 Tet
12 46 4.5×10-6 Tet
13 47 1.6×10-4 Tet
14 49 0
15 50 0
16 51 7.2×10-6 Smx
17 53 1.57×10-5
18 54 0
19 55 5.6×10-6
20 56 0
21 58 0
22 59 0
23 60 0
24 64 1.5×10-4
25 65 1.2×10-4
26 66 3.1×10-5 Tet
27 69 0

Gm – gentamicin; Smx – sulphamethoxazole-trimetoprim; Tet – tetracycline

Molecular detection of resistance genes

PCR identified blaCTX-M-1 cluster genes in 21 isolates, of which seven tested positive for blaCTX-M-15. Fourteen isolates tested positive for blaTEM and none for blaSHV genes. ISEcp was found in only one isolate, whereas IS26 tested negative. The same bla genes were found in donor isolates and their respective transconjugants. Six isolates did not harbour any bla genes in spite of being phenotypically positive for ESBLs, as shown in Table 2. All but six isolates harboured blaCTX-ML genes, and 14 harboured additional blaTEM gene. Since blaTEM genes were not sequenced, it was not possible to distinguish between broad spectrum TEM-1 and TEM-2 β-lactamases and their ESBL variants. PCR for qnr genes yielded no amplicons.

Plasmid incompatibility groups

The most frequent plasmid incompatibility group was IncFIB, identified in eight isolates, followed by IncFIA (n=3) and Inc HI1 (n=2) (Table 2). Plasmids were not found in nine isolates.

Genotypes

Two different STs were identified: ST117 (E. coli 4) and ST155 (E. coli 23) (Table 2).

DISCUSSION

Unlike some other studies (11, 12), we found only the CTX-M-1 cluster β-lactamases, which corresponds to those found in E. coli isolates identified in humans in this geographic region and highlights the One Health concept of interdependence between human and animal health and the health of their environment. SHV and TEM variants, prevailing in the early 2000s, gave way to the CTX-M family, with blaCTX-M-15 being the most frequent allelic in clinical isolates of human origin in Bosnia and Herzegovina over the last decade (38). This indicates the possibility that farm animals get colonised with ESBL isolates from farm workers handling the animals, although there are no bibliographical references to support that mode of transmission. Previous studies have demonstrated the opposite direction of transmission, that is, from broilers to farm workers (39, 40).

Whichever the direction, transmission between humans and broilers can occur at any point, even without antibiotic pressure, and therefore presents a serious public health issue (41).

Even though the CTX-M-1 cluster was dominant in our poultry isolates, similar to the report in broilers and humans working on the farms in the Netherlands (42, 43) and Hungary (44), the MICs of ceftazidime much lower than those reported in human isolates, and resistance to non-β-lactam antibiotics, usually mediated by the same plasmids coding for ESBLs, was rare.

Six isolates were phenotypically positive for ESBLs, but yielded no product with primers specific for common types of ESBLs, as they produced either rare ESBL types (like VEB, GES, or IBC) not analysed in our study or false positive results.

To our surprise, we found ISEcp in only one isolate, in spite of high blaCTX-M gene transfer and the fact that this insertion sequence promotes CTX-M mobility and expression. However, its lack is in line with low ceftazidime and cefepime MICs.

Four isolates in our study exhibited cefoxitin resistance and tested positive in inhibitor-based test with PBA, which points to the production of pAmpC, but the PCR for common AmpC β-lactamases was negative. This points to the low specificity of phenotypic tests. Similarly, nine isolates exhibited resistance to ciprofloxacin, but the PCR for qnr genes yielded no products. A likely explanation is that this resistance was due to chromosomal mutations of the gyrA and parC genes as previously reported in other Enterobacterales (45). This is in line with the fact that quinolone resistance was not transferable.

Five isolates were resistant to a combination of amoxicillin and clavulanic acid, but we found no inhibitor-resistant TEMs. This resistance may therefore be owed to ESBL overexpression reported in human CTX-M producing E. coli isolates (46).

IncI1 plasmid identified in some of the isolates and their transconjugants was previously identified in TEM-52-producing Salmonella enterica in Belgian and French poultry (47). This proves the ability of plasmids to acquire various resistance genes and spread them among different Enterobacterales. IncFIA plasmid was found to carry the blaCTX-M-15 gene in human E. coli isolates from Croatia (48).

The same plasmid showed co-transfer of tetracycline resistance. This warrants for caution in the application of tetracycline in chicken food, as it can exert selection pressure for the transfer of ESBL-encoding plasmids.

In this study, two different STs were found: ST117 and ST155.

CONCLUSION

This study showed that chickens act as a reservoir of ESBL-producing strains and pose a health risk to humans. Interestingly, the isolates possessed the same ESBLs as previously reported in humans from the same region. Although epidemiological links are likely to exist between livestock and farm workers, one limitation of our study is that it did not look for human ESBL-producing E. coli to investigate their transfer to/from farm workers. Other limitations include a relatively small number of isolates and genotyping of only two isolates instead of all 27 that would include methods such as pulsed-field gel electrophoresis or rep-PCR. Moreover, we did not sequence the blaTEM genes and therefore could not distinguish between the broad-spectrum TEM-1 and TEM-2 β-lactamases and TEM ESBLs.

Even with these limitations, however, our study provides a detailed molecular analysis of resistance determinants from a lot of farms, and therefore an insightful overview of ESBL distribution in Bosnian and Herzegovinian poultry. It also highlights the need for parallel studies of antimicrobial resistance in humans and animals. With that in mind, our future research will involve human subjects working with livestock to compare human and animal isolates and gauge the threat for public health.

Footnotes

Conflicts of interest: None to declare.

REFERENCES

  • 1.Kliebe C, Nies B, Meyer J, Tolxdorf-Neutzling R, Wiedemann B. Evolution of plasmid encoded resistance to broad-spectrum cephalosporins. Antimicrob Agents Chemother 1985;8:302–7. doi: 10.1128/aac.28.2.302 [DOI] [PMC free article] [PubMed]; Kliebe C, Nies B, Meyer J, Tolxdorf-Neutzling R, Wiedemann B.. Evolution of plasmid encoded resistance to broad-spectrum cephalosporins. Antimicrob Agents Chemother. 1985;8:302–7. doi: 10.1128/aac.28.2.302. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Bradford PA. Extended-spectrum β-lactamases in the 21st Century: Characterization, epidemiology, and detection of this important resistance threat. Clin Microbiol Rev 2001;14:933–51. doi: 10.1128/CMR.14.4.933-951.2001 [DOI] [PMC free article] [PubMed]; Bradford PA.. Extended-spectrum β-lactamases in the 21st Century: Characterization, epidemiology, and detection of this important resistance threat. Clin Microbiol Rev. 2001;14:933–51. doi: 10.1128/CMR.14.4.933-951.2001. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Bonnin RA, Nordmann P, Potron A, Lecuyer H, Zahar JR, Poirel L. Carbapenem-hydrolyzing GES-type extended-spectrum β-lactamase in Acinetobacter baumannii. Antimicrob Agents Chemother 2011;55:349–54. doi: 10.1128/AAC.00773-10 [DOI] [PMC free article] [PubMed]; Bonnin RA, Nordmann P, Potron A, Lecuyer H, Zahar JR, Poirel L.. Carbapenem-hydrolyzing GES-type extended-spectrum β-lactamase in Acinetobacter baumannii. Antimicrob Agents Chemother. 2011;55:349–54. doi: 10.1128/AAC.00773-10. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Nordmann P, Guibert M. Extended-spectrum β-lactamases in Pseudomonas aeruginosa. J Antimicrob Chemother 1998;42:128–31. doi: 10.1093/jac/42.2.128 [DOI] [PubMed]; Nordmann P, Guibert M.. Extended-spectrum β-lactamases in Pseudomonas aeruginosa. J Antimicrob Chemother. 1998;42:128–31. doi: 10.1093/jac/42.2.128. doi: [DOI] [PubMed] [Google Scholar]
  • 5.Rossolini GM, D’Andrea MM, Mugnaioli C. The spread of CTX-M-type extended-spectrum β-lactamases. Clin Microbiol Infect 2008;14:33–41. doi: 10.1111/j.1469-0691.2007.01867.x [DOI] [PubMed]; Rossolini GM, D’Andrea MM, Mugnaioli C.. The spread of CTX-M-type extended-spectrum β-lactamases. Clin Microbiol Infect. 2008;14:33–41. doi: 10.1111/j.1469-0691.2007.01867.x. doi: [DOI] [PubMed] [Google Scholar]
  • 6.Bonnet R. Growing group of extended-spectrum β-lactamases: the CTX-M enzymes. Antimicrob Agents Chemother 2004;48:1–14. doi: 10.1128/AAC.48.1.1-14.2004 [DOI] [PMC free article] [PubMed]; Bonnet R.. Growing group of extended-spectrum β-lactamases: the CTX-M enzymes. Antimicrob Agents Chemother. 2004;48:1–14. doi: 10.1128/AAC.48.1.1-14.2004. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Livermore DM, Canton R, Gniadkowski M, Nordmann P, Rossolini GM, Arlet G, Ayala J, Coque TM, Kern-Zdanowicz I, Luzzaro F, Poirel L, Woodford N. CTX-M: changing the face of ESBLs in Europe. J Antimicrob Chemother 2007;59:165–74. doi: 10.1093/jac/dkl483 [DOI] [PubMed]; Livermore DM, Canton R, Gniadkowski M, Nordmann P, Rossolini GM, Arlet G, Ayala J, Coque TM, Kern-Zdanowicz I, Luzzaro F, Poirel L, Woodford N.. CTX-M: changing the face of ESBLs in Europe. J Antimicrob Chemother. 2007;59:165–74. doi: 10.1093/jac/dkl483. doi: [DOI] [PubMed] [Google Scholar]
  • 8.Pitout JD, Nordmann P, Laupland KB, Poirel L. Emergence of Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs) in the community. J Antimicrob Chemother 2005;56:52–9. doi: 10.1093/jac/dki166 [DOI] [PubMed]; Pitout JD, Nordmann P, Laupland KB, Poirel L.. Emergence of Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs) in the community. J Antimicrob Chemother. 2005;56:52–9. doi: 10.1093/jac/dki166. doi: [DOI] [PubMed] [Google Scholar]
  • 9.Poirel L, Madec JY, Lupo A, Schink AK, Kieffer N, Nordmann P, Schwarz S. Antimicrobial Resistance in Escherichia coli. Microbiol Spectr 2018;6(4). doi: 10.1128/microbiolspec. ARBA-0026-2017 [DOI] [PMC free article] [PubMed]; Poirel L, Madec JY, Lupo A, Schink AK, Kieffer N, Nordmann P, Schwarz S.. Antimicrobial Resistance in Escherichia coli. Microbiol Spectr. 2018;6(4) doi: 10.1128/microbiolspec.ARBA-0026-2017. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Jacoby GA. AmpC β-lactamases. J Clin Microbiol 2009;22:161–82. doi: 10.1128/CMR.00036-08 [DOI] [PMC free article] [PubMed]; Jacoby GA.. AmpC β-lactamases. J Clin Microbiol. 2009;22:161–82. doi: 10.1128/CMR.00036-08. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Liu JH, Wei SY, Ma JY, Zeng ZL, Lü DH, Yang GX, Chen ZL. Detection and characterisation of CTX-M and CMY-2 beta-lactamases among Escherichia coli isolates from farm animals in Guangdong Province of China. Int J Antimicrob Agents 2007;29:576–81. doi: 10.1016/j.ijantimicag.2006.12.015 [DOI] [PubMed]; Liu JH, Wei SY, Ma JY, Zeng ZL, Lü DH, Yang GX, Chen ZL.. Detection and characterisation of CTX-M and CMY-2 beta-lactamases among Escherichia coli isolates from farm animals in Guangdong Province of China. Int J Antimicrob Agents. 2007;29:576–81. doi: 10.1016/j.ijantimicag.2006.12.015. doi: [DOI] [PubMed] [Google Scholar]
  • 12.Cortés P, Blanc V, Mora A, Dahbi G, Blanco JE, Blanco M, López C, Andreu A, Navarro F, Alonso MP, Bou G, Blanco J, Llagostera M. Isolation and characterization of potentially pathogenic antimicrobial-resistant Escherichia coli strains from chicken and pig farms in Spain. Appl Environ Microbiol 2010;76:2799–805. doi: 10.1128/AEM.02421-09 [DOI] [PMC free article] [PubMed]; Cortés P, Blanc V, Mora A, Dahbi G, Blanco JE, Blanco M, López C, Andreu A, Navarro F, Alonso MP, Bou G, Blanco J, Llagostera M.. Isolation and characterization of potentially pathogenic antimicrobial-resistant Escherichia coli strains from chicken and pig farms in Spain. Appl Environ Microbiol. 2010;76:2799–805. doi: 10.1128/AEM.02421-09. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Ewers C, Bethe A, Semmler T, Guenther S, Wieler LH. Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals, and their putative impact on public health: a global perspective. Clin Microbiol Infect 2012;18:646–55. doi: 10.1111/j.1469-0691.2012.03850 [DOI] [PubMed]; Ewers C, Bethe A, Semmler T, Guenther S, Wieler LH.. Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals, and their putative impact on public health: a global perspective. Clin Microbiol Infect. 2012;18:646–55. doi: 10.1111/j.1469-0691.2012.03850. doi: [DOI] [PubMed] [Google Scholar]
  • 14.Ilyas S, Rasool MH, Arshed MJ, Qamar MU, Aslam B, Almatroudi A, Khurshid M. The Escherichia coli sequence type 131 harboring extended-spectrum beta-lactamases and carbapenemases genes from poultry birds. Infect Drug Resist 2021;14:805–13. doi: 10.2147/IDR.S296219 [DOI] [PMC free article] [PubMed]; Ilyas S, Rasool MH, Arshed MJ, Qamar MU, Aslam B, Almatroudi A, Khurshid M.. The Escherichia coli sequence type 131 harboring extended-spectrum beta-lactamases and carbapenemases genes from poultry birds. Infect Drug Resist. 2021;14:805–13. doi: 10.2147/IDR.S296219. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Schink AK, Kadlec K, Kaspar H, Mankertz J, Schwarz S. Analysis of extended-spectrum-β-lactamase-producing Escherichia coli isolates collected in the GERM-Vet monitoring programme. J Antimicrob Chemother 2013;68:1741–9. doi: 10.1093/jac/dkt123 [DOI] [PubMed]; Schink AK, Kadlec K, Kaspar H, Mankertz J, Schwarz S.. Analysis of extended-spectrum-β-lactamase-producing Escherichia coli isolates collected in the GERM-Vet monitoring programme. J Antimicrob Chemother. 2013;68:1741–9. doi: 10.1093/jac/dkt123. doi: [DOI] [PubMed] [Google Scholar]
  • 16.Briñas L, Zarazaga M, Sáenz Y, Ruiz-Larrea F, Torres C. Beta-lactamases in ampicillin-resistant Escherichia coli isolates from foods, humans, and healthy animals. Antimicrob Agents Chemother 2002;46:3156–63. doi: 10.1128/aac.46.10.3156-3163.2002 [DOI] [PMC free article] [PubMed]; Briñas L, Zarazaga M, Sáenz Y, Ruiz-Larrea F, Torres C.. Beta-lactamases in ampicillin-resistant Escherichia coli isolates from foods, humans, and healthy animals. Antimicrob Agents Chemother. 2002;46:3156–63. doi: 10.1128/aac.46.10.3156-3163.2002. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Vinueza-Burgos C, Ortega-Paredes D, Narváez C, De Zutter L, Zurita J. Characterization of cefotaxime resistant Escherichia coli isolated from broiler farms in Ecuador. PLoS One 2019;14:e0207567. doi: 10.1371/journal.pone.0207567 [DOI] [PMC free article] [PubMed]; Vinueza-Burgos C, Ortega-Paredes D, Narváez C, De Zutter L, Zurita J.. Characterization of cefotaxime resistant Escherichia coli isolated from broiler farms in Ecuador. PLoS One. 2019;14:e0207567. doi: 10.1371/journal.pone.0207567. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Tonu MS, Sufian S, Sarker, Kamal MM, Rahman MH, Hossain MM. Pathological study on Colibacillosis in chickens and detection of Escherichia coli by PCR. Bangl J Vet Med 2011;9:17–25. doi: 10.3329/bjvm.v9i1.11205 [DOI]; Tonu MS, Sufian S, Sarker, Kamal MM, Rahman MH, Hossain MM.. Pathological study on Colibacillosis in chickens and detection of Escherichia coli by PCR. Bangl J Vet Med. 2011;9:17–25. doi: 10.3329/bjvm.v9i1.11205. doi: [DOI] [Google Scholar]
  • 19.The Clinical and Laboratory Standard Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 22nd Informational Supplement. Approved standard M100-S22. Wayne (PA): CLSI; 2016.; The Clinical and Laboratory Standard Institute (CLSI) Performance Standards for Antimicrobial Susceptibility Testing. 22nd Informational Supplement. Approved standard M100-S22. Wayne (PA): CLSI; 2016. [Google Scholar]
  • 20.Jarlier V, Nicolas MH, Fournier G, Philippon A. Extended broad-spectrum β-lactamases conferring transferable resistance to newer β-lactam agents in Enterobacteriaceae: hospital prevalence and susceptibility patterns. Rev Infect Dis 1988;10:867–78. doi: 10.1093/clinids/10.4.867 [DOI] [PubMed]; Jarlier V, Nicolas MH, Fournier G, Philippon A.. Extended broad-spectrum β-lactamases conferring transferable resistance to newer β-lactam agents in Enterobacteriaceae: hospital prevalence and susceptibility patterns. Rev Infect Dis. 1988;10:867–78. doi: 10.1093/clinids/10.4.867. doi: [DOI] [PubMed] [Google Scholar]
  • 21.Van der Zwaluw K, de Haan A, Pluister GN, Bootsma HJ, de Neeling AJ, Schouls LM. The carbapenem-inacitvation method (CIM) a simple and low-cost alternative for the Carba NP test to assess phenotypic carbapenemase activity in Gram-negative rods. PloS One 2015;10(3):e0123690. doi: 10.1371/journal. pone.0123690 [DOI] [PMC free article] [PubMed]; Van der Zwaluw K, de Haan A, Pluister GN, Bootsma HJ, de Neeling AJ, Schouls LM.. The carbapenem-inacitvation method (CIM) a simple and low-cost alternative for the Carba NP test to assess phenotypic carbapenemase activity in Gram-negative rods. PloS One. 2015;10(3):e0123690. doi: 10.1371/journal.pone.0123690. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 22.Coudron PE. Inhibitor-based methods for detection of plasmid-mediated AmpC β-lactamases in Klebsiella spp., Escherichia coli and Proteus mirabilis. J Clin Microbiol 2005;43:4163–7. doi: 10.1128/JCM.43.8.4163-4167.2005 [DOI] [PMC free article] [PubMed]; Coudron PE.. Inhibitor-based methods for detection of plasmid-mediated AmpC β-lactamases in Klebsiella spp., Escherichia coli and Proteus mirabilis. J Clin Microbiol. 2005;43:4163–7. doi: 10.1128/JCM.43.8.4163-4167.2005. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Elwell LP, Falkow S. The characterization of R plasmids and the detection of plasmid-specified genes. U: Lorian V, editor. Antibiotics in laboratory medicine. 2nd ed. Baltimore (MD): Williams and Wilkins; 1986. p. 683–721.; Elwell LP, Falkow S. Lorian V. Antibiotics in laboratory medicine. 2nd ed. Baltimore (MD): Williams and Wilkins; 1986. The characterization of R plasmids and the detection of plasmid-specified genes; pp. 683–721. U: editor. [Google Scholar]
  • 24.Dashti AA, Jadaon MM, Abdulsamad AM, Dashti HM. Heat treatment of bacteria: A simple method of DNA extraction for molecular techniques. Kuwait Med J 2009;41:117–22.; Dashti AA, Jadaon MM, Abdulsamad AM, Dashti HM.. Heat treatment of bacteria: A simple method of DNA extraction for molecular techniques. Kuwait Med J. 2009;41:117–22. [Google Scholar]
  • 25.Arlet G, Brami G, Décrè D, Flippo A, Gaillot O, Lagrange PH, Philippon A. Molecular characterization by PCR restriction fragment polymorphism of TEM β-lactamases. FEMS Microbiol Lett 1995;134:203–8. doi: 10.1111/j.1574-6968.1995.tb07938.x [DOI] [PubMed]; Arlet G, Brami G, Décrè D, Flippo A, Gaillot O, Lagrange PH, Philippon A.. Molecular characterization by PCR restriction fragment polymorphism of TEM β-lactamases. FEMS Microbiol Lett. 1995;134:203–8. doi: 10.1111/j.1574-6968.1995.tb07938.x. doi: [DOI] [PubMed] [Google Scholar]
  • 26.Nüesch-Inderbinen MT, Hächler H, Kayser FH. Detection of genes coding for extended-spectrum SHV β-lactamases in clinical isolates by a molecular genetic method, and comparison with the E test. Eur J Clin Microbiol Infect Dis 1996;15:398–402. doi: 10.1007/BF01690097 [DOI] [PubMed]; Nüesch-Inderbinen MT, Hächler H, Kayser FH.. Detection of genes coding for extended-spectrum SHV β-lactamases in clinical isolates by a molecular genetic method, and comparison with the E test. Eur J Clin Microbiol Infect Dis. 1996;15:398–402. doi: 10.1007/BF01690097. doi: [DOI] [PubMed] [Google Scholar]
  • 27.Woodford N, Ward ME, Kaufmann ME, Turton J, Fagan EJ, James D, Johnson AP, Pike R, Warner M, Cheasty T, Pearson A, Harry S, Leach JB, Loughrey A, Lowes JA, Warren RE, Livermore DM. Community and hospital spread of Escherichia coli producing CTX-M extended-spectrum β-lactamases in the UK. J Antimicrob Chemother 2004;54:735–43. doi: 10.1093/jac/dkh424 [DOI] [PubMed]; Woodford N, Ward ME, Kaufmann ME, Turton J, Fagan EJ, James D, Johnson AP, Pike R, Warner M, Cheasty T, Pearson A, Harry S, Leach JB, Loughrey A, Lowes JA, Warren RE, Livermore DM.. Community and hospital spread of Escherichia coli producing CTX-M extended-spectrum β-lactamases in the UK. J Antimicrob Chemother. 2004;54:735–43. doi: 10.1093/jac/dkh424. doi: [DOI] [PubMed] [Google Scholar]
  • 28.Pagani L, Mantengoli E, Migliavacca R, Nucleo E, Pollini S, Spalla M, Daturi R, Romero E, Rossolini GM. Multifocal detection of multidrug-resistant Pseudomonas aeruginosa producing PER-1 extended-spectrum β-lactamase in Northern Italy. J Clin Microbiol 2004;42:2523–9. doi: 10.1128/JCM.42.6.2523-2529.2004 [DOI] [PMC free article] [PubMed]; Pagani L, Mantengoli E, Migliavacca R, Nucleo E, Pollini S, Spalla M, Daturi R, Romero E, Rossolini GM.. Multifocal detection of multidrug-resistant Pseudomonas aeruginosa producing PER-1 extended-spectrum β-lactamase in Northern Italy. J Clin Microbiol. 2004;42:2523–9. doi: 10.1128/JCM.42.6.2523-2529.2004. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Robicsek A, Strahilevitz J, Sahm DF, Jacoby GA, Hooper DC. The world wide emergence of plasmid-mediated quinolone resistance. Lancet Infect Dis 2006;6:629–40. doi: 10.1016/S1473-3099(06)70599-0 [DOI] [PubMed]; Robicsek A, Strahilevitz J, Sahm DF, Jacoby GA, Hooper DC.. The world wide emergence of plasmid-mediated quinolone resistance. Lancet Infect Dis. 2006;6:629–40. doi: 10.1016/S1473-3099(06)70599-0. doi: [DOI] [PubMed] [Google Scholar]
  • 30.Woodford N, Fagan EJ, Ellington MJ. Multiplex PCR for rapid detection of genes encoding CTX-M extended-spectrum β-lactamases. J Antimicrob Chemother 2006;57:154–5. doi: 10.1093/jac/dki412 [DOI] [PubMed]; Woodford N, Fagan EJ, Ellington MJ.. Multiplex PCR for rapid detection of genes encoding CTX-M extended-spectrum β-lactamases. J Antimicrob Chemother. 2006;57:154–5. doi: 10.1093/jac/dki412. doi: [DOI] [PubMed] [Google Scholar]
  • 31.Qiagen. QIAquick® Spin Handbook [displayed 26 October 2021]. Available at https://www.qiagen.com/us/resources/resourcedetail?id=95f10677-aa29-453d-a222-0e19f01ebe17&lang=en
  • 32.Saladin M, Cao VT, Lambert T, Donay JL, Herrmann JL, Ould-Hocine Z, Verdet C, Delisle F, Philippon A, Arlet G. Diversity of CTX-M β-lactamases and their promoter regions from Enterobacteriaceae isolated in three Parisian hospitals. FEMS Microbiol Lett 2002;209:161–8. doi: 10.1111/j.1574-6968.2002.tb11126.x [DOI] [PubMed]; Saladin M, Cao VT, Lambert T, Donay JL, Herrmann JL, Ould-Hocine Z, Verdet C, Delisle F, Philippon A, Arlet G.. Diversity of CTX-M β-lactamases and their promoter regions from Enterobacteriaceae isolated in three Parisian hospitals. FEMS Microbiol Lett. 2002;209:161–8. doi: 10.1111/j.1574-6968.2002.tb11126.x. doi: [DOI] [PubMed] [Google Scholar]
  • 33.Qiagen. QIAGEN® Plasmid Purification Handbook (February 2021) [displayed 26 October 2021]. Available at https://www.qiagen.com/us/resources/download.aspx?id=0bd0c5fb-c271-43e7-af43-32d539374fa9&lang=en; Qiagen. QIAGEN® Plasmid Purification Handbook (February 2021) [displayed 26 October 2021]. Available at https://www.qiagen.com/us/resources/download.aspx?id=0bd0c5fb-c271-43e7-af43-32d539374fa9&lang=en .
  • 34.Carattoli A, Bertini A, Villa L, Falbo V, Hopkins KL, Threlfall EJ. Identification of plasmids by PCR-based replicon typing. J Microbiol Methods 2005;63:219–28. doi: 10.1016/j. mimet.2005.03.018 [DOI] [PubMed]; Carattoli A, Bertini A, Villa L, Falbo V, Hopkins KL, Threlfall EJ.. Identification of plasmids by PCR-based replicon typing. J Microbiol Methods. 2005;63:219–28. doi: 10.1016/j.mimet.2005.03.018. doi: [DOI] [PubMed] [Google Scholar]
  • 35.Carattoli A, Sieffert S, Schwendener S, Perreten V, Endimiani A. Differentiation of IncL and IncM plasmids associated with the spread of clinically relevant antimicrobial resistance. PloS One 2015;10(5):e0123063. doi: 10.1371/journal.pone.0123063 [DOI] [PMC free article] [PubMed]; Carattoli A, Sieffert S, Schwendener S, Perreten V, Endimiani A.. Differentiation of IncL and IncM plasmids associated with the spread of clinically relevant antimicrobial resistance. PloS One. 2015;10(5):e0123063. doi: 10.1371/journal.pone.0123063. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Wirth T, Falush D, Lan R, Colles F, Mensa P, Wieler LH, Karch H, Reeves PR, Maiden MC, Ochman H, Achtman M. Sex and virulence in Escherichia coli: an evolutionary perspective. Mol Microbiol 2006;60:5:1136–51. doi: 10.1111/j.1365-2958.2006.05172.x [DOI] [PMC free article] [PubMed]; Wirth T, Falush D, Lan R, Colles F, Mensa P, Wieler LH, Karch H, Reeves PR, Maiden MC, Ochman H, Achtman M.. Sex and virulence in Escherichia coli: an evolutionary perspective. Mol Microbiol. 2006;60:5, 1136–51. doi: 10.1111/j.1365-2958.2006.05172.x. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Seo KW, Lee YJ. The occurrence of CTX-M-producing E. coli in the broiler parent stock in Korea. Poult Sci 2021;100:1008–15. doi: 10.1016/j.psj.2020.09.005 [DOI] [PMC free article] [PubMed]; Seo KW, Lee YJ.. The occurrence of CTX-M-producing E. coli in the broiler parent stock in Korea. Poult Sci. 2021;100:1008–15. doi: 10.1016/j.psj.2020.09.005. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38.Ibrahimagić A, Bedenić B, Kamberović F, Uzunović S. High prevalence of CTX-M-15 and first report of CTX-M-3, CTX-M-22, CTX-M-28 and plasmid-mediated AmpC beta-lactamase producing Enterobacteriaceae causing urinary tract infections in Bosnia and Herzegovina in hospital and community settings. J Jnfect Chemot 2015;21:363–9. doi: 10.1016/j.jiac.2015.01.003 [DOI] [PubMed]; Ibrahimagić A, Bedenić B, Kamberović F, Uzunović S.. High prevalence of CTX-M-15 and first report of CTX-M-3, CTX-M-22, CTX-M-28 and plasmid-mediated AmpC beta-lactamase producing Enterobacteriaceae causing urinary tract infections in Bosnia and Herzegovina in hospital and community settings. J Jnfect Chemot. 2015;21:363–9. doi: 10.1016/j.jiac.2015.01.003. doi: [DOI] [PubMed] [Google Scholar]
  • 39.Huijbers PMC, Graat EAM, Haenen APJ, van Santen MG, van Essen-Zandbergen A, Mevius DJ, van Duijkeren E, van Hoek AHAM. Extended-spectrum and AmpC β-lactamase-producing Escherichia coli in broilers and people living and/or working on broiler farms: prevalence, risk factors and molecular characteristics. J Antimicrob Chemother 2014;69:2669–75. doi: 10.1093/jac/dku178 [DOI] [PubMed]; Huijbers PMC, Graat EAM, Haenen APJ, van Santen MG, van Essen-Zandbergen A, Mevius DJ, van Duijkeren E, van Hoek AHAM.. Extended-spectrum and AmpC β-lactamase-producing Escherichia coli in broilers and people living and/or working on broiler farms: prevalence, risk factors and molecular characteristics. J Antimicrob Chemother. 2014;69:2669–75. doi: 10.1093/jac/dku178. doi: [DOI] [PubMed] [Google Scholar]
  • 40.Aworh MK, Kwaga J, Okolocha E, Harden L, Hull D, Hendriksen RS, Thakur S. Extended-spectrum ß-lactamase-producing Escherichia coli among humans, chickens and poultry environments in Abuja, Nigeria. One Health Outlook 2020;2:8. doi: 10.1186/s42522-020-00014-7 [DOI] [PMC free article] [PubMed]; Aworh MK, Kwaga J, Okolocha E, Harden L, Hull D, Hendriksen RS, Thakur S.. Extended-spectrum ß-lactamase-producing Escherichia coli among humans, chickens and poultry environments in Abuja, Nigeria. One Health Outlook. 2020;2:8. doi: 10.1186/s42522-020-00014-7. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 41.Cardozo MV, Liakopoulos A, Brouwer M, Kant A, Pizauro LJL, Borzi MM, Mevius D, de Ávila FA. Occurrence and molecular characteristics of extended-spectrum beta-lactamase-producing Enterobacterales recovered from chicken, chicken meat, and human infections in Sao Paulo State, Brazil. Front Microbiol 2021;12:628738. doi: 10.3389/fmicb.2021.628738 [DOI] [PMC free article] [PubMed]; Cardozo MV, Liakopoulos A, Brouwer M, Kant A, Pizauro LJL, Borzi MM, Mevius D, de Ávila FA.. Occurrence and molecular characteristics of extended-spectrum beta-lactamase-producing Enterobacterales recovered from chicken, chicken meat, and human infections in Sao Paulo State, Brazil. Front Microbiol. 2021;12:628738. doi: 10.3389/fmicb.2021.628738. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 42.Huijbers PMC, Graat EAM, van Hoek AHAM, Veenman C, de Jong MCM, van Duijkeren E. Transmission dynamics of extended-spectrum β-lactamase and AmpC β-lactamase-producing Escherichia coli in a broiler flock without antibiotic use. Prev Vet Med 2016;131:12–9. doi: 10.1016/j. prevetmed.2016.07.001 [DOI] [PubMed]; Huijbers PMC, Graat EAM, van Hoek AHAM, Veenman C, de Jong MCM, van Duijkeren E.. Transmission dynamics of extended-spectrum β-lactamase and AmpC β-lactamase-producing Escherichia coli in a broiler flock without antibiotic use. Prev Vet Med. 2016;131:12–9. doi: 10.1016/j.prevetmed.2016.07.001. doi: [DOI] [PubMed] [Google Scholar]
  • 43.Huijbers PM, van Hoek AH, Graat EA, Haenen AP, Florijn A, Hengeveld PD, van Duijkeren E. Methicillin-resistant Staphylococcus aureus and extended-spectrum and AmpC β-lactamase-producing Escherichia coli in broilers and in people living and/or working on organic broiler farms. Vet Microbiol 2015;176:120–5. doi: 10.1016/j.vetmic.2014.12.010 [DOI] [PubMed]; Huijbers PM, van Hoek AH, Graat EA, Haenen AP, Florijn A, Hengeveld PD, van Duijkeren E.. Methicillin-resistant Staphylococcus aureus and extended-spectrum and AmpC β-lactamase-producing Escherichia coli in broilers and in people living and/or working on organic broiler farms. Vet Microbiol. 2015;176:120–5. doi: 10.1016/j.vetmic.2014.12.010. doi: [DOI] [PubMed] [Google Scholar]
  • 44.Balázs B, Nagy JB, Tóth Z, Nagy F, Károlyi S, Turcsányi I, Bistyák A, Kálmán A, Sárközi R, Kardos G. Occurrence of Escherichia coli producing extended spectrum β-lactamases in food-producing animals. Acta Vet Hung 2021;69:211–5. doi: 10.1556/004.2021.00036 [DOI] [PubMed]; Balázs B, Nagy JB, Tóth Z, Nagy F, Károlyi S, Turcsányi I, Bistyák A, Kálmán A, Sárközi R, Kardos G.. Occurrence of Escherichia coli producing extended spectrum β-lactamases in food-producing animals. Acta Vet Hung. 2021;69:211–5. doi: 10.1556/004.2021.00036. doi: [DOI] [PubMed] [Google Scholar]
  • 45.Damjanova I, Tóth A, Pászti J, Hajbel-Vékony G, Jakab M, Berta J, Milch H, Füzi M. Expansion and countrywide dissemination of ST11, ST15 and ST147 ciprofloxacin-resistant CTX-M-15-type beta-lactamase-producing Klebsiella pneumoniae epidemic clones in Hungary in 2005-the new ‘MRSAs’? J Antimicrob Chemother 2008;62:978–85. doi: 10.1093/jac/dkn287 [DOI] [PubMed]; Damjanova I, Tóth A, Pászti J, Hajbel-Vékony G, Jakab M, Berta J, Milch H, Füzi M.. Expansion and countrywide dissemination of ST11, ST15 and ST147 ciprofloxacin-resistant CTX-M-15-type beta-lactamase-producing Klebsiella pneumoniae epidemic clones in Hungary in 2005-the new ‘MRSAs’? J Antimicrob Chemother. 2008;62:978–85. doi: 10.1093/jac/dkn287. doi: [DOI] [PubMed] [Google Scholar]
  • 46.Edelstein M, Pimkin M, Palagin I, Edelstein I, Stratchounski L. Prevalence and molecular epidemiology of CTX-M extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in Russian hospitals. Antimicrob Agents Chemother 2003;47:3724–32. doi: 10.1128/AAC.47.12.3724-3732.2003 [DOI] [PMC free article] [PubMed]; Edelstein M, Pimkin M, Palagin I, Edelstein I, Stratchounski L.. Prevalence and molecular epidemiology of CTX-M extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in Russian hospitals. Antimicrob Agents Chemother. 2003;47:3724–32. doi: 10.1128/AAC.47.12.3724-3732.2003. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 47.Cloeckaert A, Praud K, Doublet B, Bertini A, Carattoli A, Butaye P, Imberechts H, Bertrand S, Collard JM, Arlet G, Weill FX. Dissemination of an extended-spectrum-beta-lactamase blaTEM-52 gene-carrying IncI1 plasmid in various Salmonella enterica serovars isolated from poultry and humans in Belgium and France between 2001 and 2005. Antimicrob Agents Chemother 2007;51:1872–5. doi: 10.1128/AAC.01514-06 [DOI] [PMC free article] [PubMed]; Cloeckaert A, Praud K, Doublet B, Bertini A, Carattoli A, Butaye P, Imberechts H, Bertrand S, Collard JM, Arlet G, Weill FX.. Dissemination of an extended-spectrum-beta-lactamase blaTEM-52 gene-carrying IncI1 plasmid in various Salmonella enterica serovars isolated from poultry and humans in Belgium and France between 2001 and 2005. Antimicrob Agents Chemother. 2007;51:1872–5. doi: 10.1128/AAC.01514-06. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 48.Literacka E, Bedenić B, Baraniak A, Fiett J, Tonkić M, Jajić-Benčić I, Gniadkowski M. blaCTX-M genes in Escherichia coli from Croatian hospitals are located in new (blaCTX-M-3) and widely spread (blaCTX-M-3a, blaCTX-M-15) genetic structures. Antimicrob Agents Chemother 2009;53:1630–5. doi: 10.1128/AAC.01431-08 [DOI] [PMC free article] [PubMed]; Literacka E, Bedenić B, Baraniak A, Fiett J, Tonkić M, Jajić-Benčić I, Gniadkowski M.. blaCTX-M genes in Escherichia coli from Croatian hospitals are located in new (blaCTX-M-3) and widely spread (blaCTX-M-3a, blaCTX-M-15) genetic structures. Antimicrob Agents Chemother. 2009;53:1630–5. doi: 10.1128/AAC.01431-08. doi: [DOI] [PMC free article] [PubMed] [Google Scholar]

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