SEROTYPING AND ANTIMICROBIAL DRUG RESISTANCE OF SALMONELLA ISOLATED FROM LETTUCE AND HUMAN DIARRHEA SAMPLES IN BURKINA FASO

Prevalence and Antibiotic Susceptibility of Pathogenic Enterobacteria Strains from Three Biotopes in the City of Ouagadougou (Burkina Faso)

Purpose

The emergence of antibiotic resistance in pathogenic Enterobacteriaceae is a public health problem in tropical countries such as Burkina Faso. Antibiotic resistance could be identified using a variety of approaches. This study aimed to estimate the prevalence of pathogenic enterobacteria strains from three sources, as well as their antibiotic resistance profile to biotope and climatic season.

Material and Methods

The methodological approach consisted of identifying Enterobacteriaceae from human (urine, stool), animal (eggs, milk, fish), and environmental (soil, lettuce) samples, followed by assessing their antibiotic susceptibility. Samples were collected from February to December 2023. Bacterial species were isolated and phenotypically identified (morphologically, culturally, biochemically, and antigenically) using standard methods. The prevalence of bacterial susceptibility to ten antibiotics was determined using the agar disk diffusion method. The collected data were analyzed with IBM SPSS Statistics 25 software.

Results

A total of 615 Enterobacteriaceae isolates were collected, including 300, 168, and 147 samples from human, animal, and environmental sources respectively. Phenotypic characteristics allowed to partially identify 43 species, among these 29.76% belonged to Escherichia coli, 24.72% to Enterobacter cloacae, 13.82% to Klebsiella pneumoniae, 3.41% to Enterobacter sakazakii and 2.6% to Klebsiella oxytoca. Bacterial resistance rates were: aminopenicillins (54.8%), first-generation cephalosporins (35.3%), sulfonamides (33.3%), third-generation cephalosporins (30.7%), fourth-generation cephalosporins (22.5%), fluoroquinolones (21.8%), phenicols (16.8%), and carbapenems (16.2%). The distribution of antibiotic resistance was 45.3% from human sources, 19.3% from animal sources, and 13.8% from environmental sources.

Conclusion

The results indicate that resistant bacteria can come from any of the three biotopes, with human origin being the most frequent. The high prevalence of resistance to the antibiotics tested in isolated bacteria raises interest in investigating the genetic factors responsible.

Virulence genes and pulsed-field gel electrophoresis profiles of Shiga toxin-producing Escherichia coli isolated from different food samples and patients with acute diarrhea

Background and Objectives

Escherichia coli O157: H7 is one of the most important causes of hemorrhagic colitis, and hemolytic uremic syndrome. The present study aimed to isolate E. coli O157: H7 from foods and patients with hemorrhagic colitis, and identify Shiga toxin genes, phylogenetic comparison, and antibiotic resistance of the isolates.

Materials and Methods

In total 400 samples, including patients stool and food were taken in Isfahan-Iran province. Phenotypic tests and PCR were performed to identify Shiga toxin-producing E. coli. The isolated strains were compared phylogenetically by PFGE. Agar disk diffusion was performed to identify the antibiotic resistance of the isolates.

Results

Totally, 5 isolates of fecal samples were E. coli O157, but only 2 isolates carried H7 gene. Also, 9 isolates of E. coli O157 were isolated from food samples that 3 isolates were E. coli O157: H7. The isolates carried stx1, stx2, hlyA and eaeA genes. Also, E. coli non-O157: H7 identified from samples that contained stx1, stx2, hlyA genes. The highest susceptibility to imipenem and the highest resistance to ampicillin and ciprofloxacin were observed. There was a similarity of 100% between the E. coli O157: H7 strains isolated from patients and raw milk and minced beef samples.

Conclusion

Serotypes other than the O157 of E. coli are more prevalent in patients and food. The E. coli O157: H7 isolates from patients had 100% genetic similarity with minced meat and cow milk isolates, which indicates cattle are the most important reservoir of this bacterium in Iran.

Safety of ready-to-eat chicken in Burkina Faso: Microbiological quality, antibiotic resistance, and virulence genes in Escherichia coli isolated from chicken samples of Ouagadougou

In Burkina Faso, flamed/grilled chickens are very popular and well known to consumers. The aim of this study was to evaluate the microbiological quality, the antibiotic resistance, and the virulence gene from Escherichia coli isolated from these chickens in Ouagadougou. A total of 102 grilled, flamed, and fumed chickens were collected in Ouagadougou and analyzed, using standard microbiological methods. All E. coli isolates were checked with the antimicrobial test and also typed by 16-plex PCR. The mean of aerobic mesophilic bacteria (AMB) and thermo-tolerant coliforms (TTC) was found respectively between 6.90 ± 0.12 × 107 CFU/g to 2.76 ± 0.44 × 108 CFU/g and 2.4 ± 0.82 × 107 CFU/g to 1.27 ± 0.9 × 108 CFU/g. E. coli strains were found to 27.45%. Forty samples (38.24%) were unacceptable based on the AMB load. Fifty-nine samples (57.85%) were contaminated with TTCs. Low resistance was observed with antibiotics of betalactamin family. Diarrheagenic E. coli strains were detected in 21.43% of all samples. This study showed that flamed/grilled chickens sold in Ouagadougou could pose health risks for the consumers. Need of hygienic practices or system and good manufacturing practices is necessary to improve the hygienic quality of flamed/grilled chickens. Our results highlight the need of control of good hygiene and production practices to contribute to the improvement of the safety of the products and also to avoid antibiotic resistance. Slaughter, scalding, evisceration, plucking, bleeding, washing, rinsing, preserving, grilling, and selling may be the ways of contamination.