Bacterial Species Causing Secondary Pneumonia Infection in Pregnant Women with COVID-19

ABSTRACT

Sputum samples were taken from pregnant women infected with the COVID-19, where the study was conducted on 112 cases, and the results showed that 87 cases developed secondary bacterial infections at a rate of 78% and 25 cases were negative by 22%. The samples were cultured on solid media and incubated at 37°C. Then the samples were diagnosed by biochemical tests and using the API system. Six species of bcteria have been isolated (S. aureus, K.pneumonia P. auroginosa, H. influenza, S. pneumonia S. pyogens) by 31, 29, 12, 10, 7, and 5 isolates, respectively, where the result showed that the most common types of pneumonia were S. aureus with a percentage of 34%, followed by K. pneumonia with a percentage of 29%. The sensitivity of the isolates to eight types of common antibiotics was tested (Erythromycin, Trimethoprim, Ampicillin, Tetracycline, Augmentin, Nitrofurantoin, Meropenem, and Amikacin), where the isolates showed a high resistance to antibiotics (Erythromycin, Trimethoprim, Ampicillin), a high sensitivity of 100% to the Nitrofurantoin, and an average sensitivity to other antibiotics

INTRODUCTION

Coronavirus is containing RNA and belongs to the Coronaviridae family of Nidovirales order.[1] It is one of the families that infects respiratory system, as this species was isolated for the first time in 1937 and was classified with coronaviruses because its shape resembles a crown under a microscope.[2] The known types so far are as follows: beta coronaviruses HCoV-OC43 and HCoV-HKU1; HCoV-229E and HCoV-NL63 alpha coronaviruses and a new coronavirus reported in China that was described in late 2019 which causes COVID-19.[3]

Pneumonia occurs when the lungs become infected with infections of bacterial, fungal, viral, or sometimes parasitic sources, which negatively affect the air sacs in the lung, which are called air sacs.[4,5] Symptoms of pneumonia include dry cough, chest pain, difficulty breathing, fever, and sputum discharge with coughing.[6] Diagnosis of pneumonia is based on external symptoms, physical examination, and chest X-ray.[7] Disease can be classified according to where the person was infected, such as HCP, community-acquired pneumonia, or hospital-acquired pneumonia.[7,8] Secondary infection occurs after a person has been infected with the primary infection, as some infections lead to a weakening of the immune system,[9,10] and this in turn increases the possibility of infection with other bacterial diseases. Some diseases reduce the ability of the immune system to resist harmful invaders from bacteria and viruses, and this facilitates the process of entering pathogenic germs and causing secondary infection,[11] for example, people infected with the AIDS virus reduce the ability of the immune system which leads to infection with opportunistic types because the body was not able to fight germs that the immune system can resist.[12]

MATERIALS AND METHOD

Sampling

Sputum samples were collected from pregnant women infected with COVID-19 by using sterile cotton swabs, where 112 samples were collected and then the samples were cultured on solid media by Streak plate cultures method then incubated for 24 h at 37°C, after incubation the isolates were initially diagnosed based on the phenotypic characteristics of the colonies, which included the size, edge, height, and color of the colonies, then the cells were stained with gram stain, and the phenotypic characteristics of the cells were observed under the compound light microscope, which included the shape, cell size, method of aggregation, and result of gram stain reaction, and after conducting biochemical diagnostic tests, the diagnosis was confirmed by API system.

Antibiotic susceptibility test

Eight types of common antibiotics (Erythromycin, Trimethoprim, Ampicillin, Tetracycline, Augmentin, Nitrofurantoin, Meropenem, and Amikacin) were used, and sensitivity of bacterial isolates was tested according to the standard (Kirby-Bauer method) as follows:

1. The bacterial suspension was prepared by taking (four—five) young colonies (16–24 h old) grown on agar plate and planted in 5 ml of physiological solution with good shaking to make the solution homogeneous.

2. The density of the bacterial suspension was compared with the MacFarland turbidity standard.

3. Spread the bacterial suspension on the surface of Muller–Hinton agar using a cotton swab, the disks were placed with sterile forceps on the surface of the culture plate, the dishes were incubated in the incubator for 24 h at 37°C, and after the incubation period, the diameters of the damping zones were recorded in mm around the disks and results compared with standard specifications.

RESULTS AND DISCUSSION

Sputum samples were taken from pregnant women infected with COVID-19, and the results showed that 78% of cases were infected with secondary pneumonia infection, 87 out of 112 cases, where 92 isolates were obtained from six bacterial species, after diagnosing the isolates, it was found that the most common types of pneumonia were S. aureus (34%), followed by K. pneumonia (29%), while the other types were P. auroginosa (13%), H. influenza (11%), and S. pneumonia by 11% 8% and S. pyogens at 5% as shown in Figure 1.

Figure 1.

Percentage of bacterial species that cause pneumonia

The upper and lower respiratory tracts contain normal flora. It is important here to clarify that some microbes are harmless bacteria to respiratory system, but they may lead to some serious diseases.[13,14] And current study showed resistance to most of the antibiotics used, where 100% were resistant to Trimethoprim, Erythromycin, and Ampicillin, and they showed 86% resistance to Tetracycline and 65% to Augmentin, while the collection of isolates was sensitive to Nitrofurantoin antibiotics at 100%.

Meropenem and Amikacin isolates were sensitive to them with rates of 77% and 68%, respectively. As shown in Figure 2, one of the causes of bacterial resistance to antibiotics is the indiscriminate use of medicines, which leads to the occurrence of resistant genetic mutations, and this poses a threat to human life. It led to the emergence of resistant strains.

Figure 2.

Sensitivity of isolates to the antibiotics

CONCLUSION

This study concluded that most of the people infected with COVID-19 virus developed a secondary bacterial infection by 78% and that the most bacterial types that cause pneumonia were S. aureus and K. pneumonia, and that the diagnosed isolates showed multiple resistance to antibiotics and that the effective antibiotic against all isolates was Nitrofurantoin.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.