Phenotypic and Molecular Characterization of Staphylococcaceae and Enterobacteriaceae Species Isolated from Smoked, Dried, and Braised Fish Marketed in Ouagadougou

Background: To preserve its nutritional properties, fish must have good sanitary quality. The objective of this study was to investigate some pathogens contaminating smoked, dried, and braised fish marketed in Ouagadougou. Methodology: Potential pathogens of Enterobacteriaceae and Staphylococcus were screened in eight (8) species of processed fish. The investigation of the germs was carried out following the normative methods of microbiology. The identities of the strains were determined by API 20 E (BioMerieux S.A., France) and API STAPH (BioMerieux S.A., France) kits for Enterobacteriaceae and Staphylococcus species respectively. The uidA gene profile in Escherichia coli isolates was determined by simplex PCR. The identity of Staphylococcus aureus was confirmed by amplification of specific 23S rDNA regions and nuc gene profile with PCR. Results: A total of 235 fish samples were analyzed. A diversity of Enterobacteriaceae and Staphylococcus was detected. Twenty species of Enterobacteriaceae were identified among which, the most frequent were Escherichia coli, Salmonella sp, Raoultella ornithinolytica and Serratia odorifera, respectively in 22.6%, 4.3%, 28.9%, 17.4% of the samples analyzed. However, eleven species of Staphylococcus were identified among which, Staphylococcus xylosus, Staphylococcus aureus, Staphylococcus lugdunensis, and Staphylococcus sciuri were the most frequent with respective percentages of 47.7%, 23.4%, 12.8% and 10.6% of samples. For all the samples, the species frequently isolated were: Raoultella ornithinolytica, Escherichia coli, Serratia odorifera, Staphylococcus aureus, Staphylococcus xylosus, and Staphylococcus lugdunensis. The uidA gene specific to Escherichia coli was detected in 82.85% of strains (29/35). Amplification of the specific 23S rDNA region using staur primers was observed in 98% (49/50) of the isolated Staphylococcus aureus strains and the nuc gene was detected in 86% of Staphylococcus aureus strains. Conclusion: The isolated bacteria are potential pathogens involved in foodborne illnesses and intoxications. Effective sanitary safety systems must be implemented to guarantee the sanitary quality of fish supplied to consumers.

Microbial Quality and Molecular Identification of Enterotoxigenic Staphylococcus Strains Isolated from Dried, Smoked, and Braised Fish Sold in Ouagadougou Markets

Background: The investigation of toxin genes in strains involved in staphylococcal food poisoning contributes to food safety. The aim of this study was to isolate and identify enterotoxigenic Staphylococcus strains from dried, smoked, and braised fish sold in Ouagadougou markets. Methodology: Staphylococci were isolated using standard microbiology methods. Staphylococcus strains were identified using API Staph kit (Reference # 20500, BioMerieux S.A., Marcy l'Etoile, France). The molecular identification of isolated Staphylococcus aureus strains was specifically confirmed by PCR using the Staur4 and Staur6 primers. The genes encoding enterotoxins, enterotoxin-like toxins, exfoliative toxins, and TSST-1 toxin were detected by multiplex PCR using specific primers from Inquaba Biotec West Africa Ltd, Africa's Genomics Company. Results: The results of the microbiological quality assessment indicated that most of the samples analyzed were found to be of unsatisfactory microbiological quality according to the Staphylococcus aureus microbiological criteria (m = 102). Overall, only 12.55% of samples were satisfactory, while 97.45% were unsatisfactory. The STAPH API gallery allowed the identification of the following species: Staphylococcus aureus, Staphylococcus xylosus, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus haemolyticus, Staphylococcus lentus, Staphylococcus sciuri and Staphylococcus capitis. Of the 108 Staphylococcus isolates, 81 (75%) showed at least one (1) toxin gene. Among the 21 toxin genes tested in this study, 20 genes were detected in all strains analyzed. The staphylococcal toxin genes detected were present in both Staphylococcus aureus and the other coagulase-negative strains isolated in this study. In addition, these genes are found individually or in association in certain strains. The most frequent genes detected in toxin gene-positive strains were: the tsst-1 gene in 45 isolated strains (41.7%), sei (16/14.8%), seg (13/12%), ser (7/6.5%) sec (6/5.5%), and sea (5/4.6%) for staphylococcal enterotoxins, seln (14/12.9%), selq (8/7.4%), for enterotoxin-like toxin gene and eta (3/2.7%) for exfoliative toxin genes. Conclusion: This study highlighted the pathogenicity of Staphylococcus strains isolated from dried, smoked, and braised fish sold in Ouagadougou markets. Monitoring toxin-producing strains of Staphylococcus is invaluable for better prevention of food poisoning.

Molecular Characterization and Technological Properties of Lactic Acid Bacteria, Bacillus and Yeast of Probiotic Interest Isolated from Fermented Porridges

Cereal-based porridges are among fermented foods with a composite microbiota. The objective of this work is to characterize the microbiota of porridge. Samples of porridge were collected in Ouagadougou and analyzed according to standard methods in microbiology. The presumed strains obtained were characterized by polymerase chain reaction (PCR). Technological abilities were estimated by tests for resistance to acid pH, bile, antibiotics and antimicrobial, proteolytic and lipolytic activities. All presumptive Bacillus, lactic acid bacteria and yeast were characterized by PCR. Four (BC1a;BC9b;BC2a and BC1b) strains were confirmed to Bacillus by PCR, 6 strains to Lactobacillus and only to Saccharomyces cerevisiae. All strains were sensitive to two antibiotics gentamycin and imipenem. In contrast, all strains were resistant to oxacillin, amoxicillin-clavulanic acid, streptomycin, penicillin and ticarcillin. Strains tested were resistant to bile but in terms of pH this resistance was relative. Potential probiotic strains have been shown to be effective in inhibiting pathogens. Proteolytic and lipolytic activities were positive on all strains. The characterization of strains, although concerned with a non-exhaustive list of primers, has made it possible to confirm the strains that may be of good quality probiotics if a quantitative study is carried out on technological aptitudes.

Surgical Site Infection (SSI) in the National Referral General Hospital of Ndjamena (Chad): Survey about Risk Factors

The risk to develop an infection after surgery depends on several factors. Those factors may be interdependent or not, depending on the nature of the surgery and the general condition of the patient. The aim of the present study was to identify the factors involved in the occurrence of the Surgical Site Infections (SSI) in the National referral general hospital of N’djamena (Chad). We first realized an interview in the emergency services and in the general surgery of the hospital. The information collected allowed us to draw up survey sheets. An investigation was then conducted on 152 patients who had surgery and were hospitalized during the study period. The frequency of the SSI was 33.6% (51/152). The main risk factors that we identified were the duration of hospitalization, the category of the hospitalization room, the urgent aspect of the surgical intervention, the patient’s nutritional status and the associated diseases with diabetes, which was present in 52.38% (11/21) of cases of associated pathologies. Analysis of the antibiotic prophylaxis administered to patients showed that ciprofloxacin was more effective in SSI prevention. Indeed, this antibiotic showed the fewest cases of infection with only 1.9% of patients having developed SSI. Our results show a very high frequency of SSI at the National referral general hospital of N’djamena. Poor hospital practices and factors associated to patients seem to be the most factors implicated in the SSI.

Identification of Bacteria Strains Isolated in Urinary Tract Infections and Their Antibiotic Susceptibility at the National Public Health Laboratory, Ouagadougou

Background: Urinary tract infections are still a real public health concern. The aim of this study was to identify the bacteria strains involved in urinary tract infections and to determine their antibiotic resistance profiles. Methods: Two kinds of studies were performed. The retrospective study was carried out for 2 years (from January 2018 to December 2019), and the prospective study was extended over a period of 6 months (from January to June 2020). Isolation and identification of bacteria strains were performed using conventional microbiology techniques. The strains’ resistance profiles were determined by the diffusion method on Mueller-Hinton according to the criteria of EUCAST- 2015. Fourteen (14) antibiotic discs were used depending on the isolated germ. Results: A total of 187 bacterial strains were isolated from 82 men and 105 women. Among the germs identified, 77.54% were Enterobacteriaceae and 13.36% were cocci strains. Non-fermentative gram-negative bacilli accounted for 9.08% of the isolated bacteria. The results showed that the majority of Enterobacteriaceae strains were resistant to beta-lactams: 100% to amoxicillin, 98.75% to amoxicillin + clavulanic acid, 41.76% to ceftriaxone, and 43.14% to ceftazidime. These findings were obtained with fluoroquinolones and aminoglycosides: 50.09% with ciprofloxacin, 54.04% with norfloxacin, and 22.58% with amikacin. 8.75% of the Enterobacteriaceae strains tested were resistant to imipenem. The same trends were observed with non-fer- mentative bacteria. As for the gram-positive bacteria isolated during our study, 13.33% were resistant to vancomycin, 21.05% to gentamicin, 94.12% to penicillin G, 88.89% to ampicillin, 77.78% to cefotaxime, 63.63% to kanamycin, and 52.63% to erythromycin. Conclusion: This study revealed, as in other studies, that Enterobacteriaceae strains remain the most incriminated bacteria strains in urinary tract infections, with a strong resistance to antibiotics. It is important that actions be taken to reduce the incidence of urinary tract infections and mitigate the spread of resistant bacteria.