The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010

The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE) elements were identified and annotated. A global phylogeny (378 genomes) was inferred using a single nucleotide polymorphism (SNP) analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains

Hospital-based Surveillance Provides Insights Into the Etiology of Pediatric Bacterial Meningitis in Yaoundé, Cameroon, in the Post-Vaccine Era.

BACKGROUND:Meningitis is endemic to regions of Cameroon outside the meningitis belt including the capital city, Yaoundé. Through surveillance, we studied the etiology and molecular epidemiology of pediatric bacterial meningitis in Yaoundé from 2010 to 2016. METHODS:Lumbar puncture was performed on 5958 suspected meningitis cases; 765 specimens were further tested by culture, latex agglutination, and/or polymerase chain reaction (PCR). Serotyping/grouping, antimicrobial susceptibility testing, and/or whole genome sequencing were performed where applicable. RESULTS:The leading pathogens detected among the 126 confirmed cases were Streptococcus pneumoniae (93 [73.8%]), Haemophilus influenzae (18 [14.3%]), and Neisseria meningitidis (15 [11.9%]). We identified more vaccine serotypes (19 [61%]) than nonvaccine serotypes (12 [39%]); however, in the latter years non-pneumococcal conjugate vaccine serotypes were more common. Whole genome data on 29 S. pneumoniae isolates identified related strains (<30 single-nucleotide polymorphism difference). All but 1 of the genomes harbored a resistance genotype to at least 1 antibiotic, and vaccine serotypes harbored more resistance genes than nonvaccine serotypes (P < .05). Of 9 cases of H. influenzae, 8 were type b (Hib) and 1 was type f. However, the cases of Hib were either in unvaccinated individuals or children who had not yet received all 3 doses. We were unable to serogroup the N. meningitidis cases by PCR. CONCLUSIONS:Streptococcus pneumoniae remains a leading cause of pediatric bacterial meningitis, and nonvaccine serotypes may play a bigger role in disease etiology in the postvaccine era. There is evidence of Hib disease among children in Cameroon, which warrants further investigation

Multiple contaminations of chickens with Campylobacter, Escherichia coli and Salmonella in Yaounde (Cameroon)

Introduction: Food-borne diseases associated with Campylobacter, Escherichia coli, and Salmonella are mainly caused by the consumption of raw or undercooked poultry meat. The objective of this study was to evaluate the prevalence of Campylobacter, Escherichia coli, and Salmonella in chickens. Methodology: One hundred and fifty chickens collected from eight retail markets in Yaounde were examined for the presence of Campylobacter, Escherichia coli, and Salmonella using standard bacteriological procedures. Results: Of the 150 chickens collected, 135 (90%) were contaminated with Campylobacter (68.9% C. coli and 31.1% C. jejuni). All the chickens were positive for E. coli. Among the 150 isolates, 17 (11.3%) were enteropathogenic E. coli (EPEC). Additionally, 103 Salmonella strains were recovered from 90 chickens. Salmonella Enteritidis (45.6%) and Salmonella Hadar (28.1%) were the most frequent serotypes. Multiple contamination was found in 142 chickens (94.6%), of which 83 (55.3%) were concurrently contaminated with Campylobacter, Escherichia coli, and Salmonella. Conclusion: These results show that chickens in Cameroon are highly contaminated with Campylobacter, Escherichia coli, and Salmonella. The multiple contaminations of chickens is a potential risk of infection for consumers and highlights the necessity of public awareness for food safety.  </jats:p

Bacterial Aetiologies of Lower Respiratory Tract Infections among Adults in Yaoundé, Cameroon

Lower respiratory tract infections (LRTIs) remain a challenge in African healthcare settings and only few data are available on their aetiology in Cameroon. The purpose of this study was to access the bacterial cause of LRTIs in patients in Cameroon by two methods.Methods. Participants with LRTIs were enrolled in the referral centre for respiratory diseases in Yaoundé city and its surroundings. To detect bacteria, specimens were tested by conventional bacterial culture and a commercial reverse-transcriptase real-time polymerase chain reaction (RT-PCR) assay. One hundred forty-one adult patients with LRTIs were enrolled in the study. Among the participants, 46.8% were positive for at least one bacterium.Streptococcus pneumoniaeandHaemophilus influenzaewere the most detected bacteria with 14.2% (20/141) followed byKlebsiella pneumoniae, 9.2% (13/141),Staphylococcus aureus, 7.1% (10/141), andMoraxella catarrhalis, 4.3% (6/141). Bacterial coinfection accounted for 23% (14/61) withHaemophilus influenzaebeing implicated in 19.7% (12/61). The diagnostic performance of RT-PCR for bacteria detection (43.3%) was significantly different from that of culture (17.7%) (p&lt; 0.001). OnlyStreptococcus pneumoniaedetection was associated with empyema by RT-PCR (p&lt;0.001). These findings enhance understanding of bacterial aetiologies in order to improve respiratory infection management and treatment. It also highlights the need to implement molecular tools as part of the diagnosis of LRTIs.</jats:p

Trends of Antibacterial Resistance at the National Reference Laboratory in Cameroon: Comparison of the Situation between 2010 and 2017

Introduction. Antimicrobial resistance represents a growing public health threat. One of the World Health Organization’s strategic objectives is “strengthening knowledge through surveillance and research.” Sub-Saharan African countries are still far from achieving this objective. We aimed to estimate and compare the prevalence of antibacterial resistance in 2010 and 2017 in Cameroon. Methods. We conducted a retrospective study on all clinical specimens cultured in Centre Pasteur du Cameroun (CPC) in 2010 and 2017. Data were extracted from the CPC’s laboratory data information system software and then managed and analyzed using R. Bacterial resistance rates were calculated in each year and compared using chi-square or Fisher’s tests, and relative changes were calculated. Outcomes included acquired resistance (AR), WHO priority resistant pathogens, some specific resistances of clinical interest, and resistance patterns (multi, extensively, and pan drug resistances) for five selected pathogens. Results. A total of 10,218 isolates were analyzed. The overall AR rate was 96.0% (95% CI: 95.4–96.6). Most of WHO priority bacterial resistance rates increased from 2010 to 2017. The most marked increases expressed as relative changes concerned imipenem-resistant Acinetobacter (6.2% vs. 21.6%, +248.4%, p = 0.02 ), imipenem-resistant Pseudomonas aeruginosa (13.5% vs. 23.5%, +74.1%, p &lt; 0.01 ), 3rd generation-resistant Enterobacteriaceae (23.8% vs. 40.4%, +65.8%, p &lt; 10 − 15 ), methicillin-resistant Staphylococcus aureus (27.3% vs. 46.0%, +68.6%, p &lt; 0.002 ), fluoroquinolone-resistant Salmonella (3.9% vs. 9.5%, +142.9%, p = 0.03 ), and fluoroquinolone-resistant Enterobacteriaceae (32.6% vs. 54.0%, +65.8%, p &lt; 10 − 15 ). For selected pathogens, global multidrug resistance was high in 2010 and 2017 (74.9% vs. 78.0% +4.1%, p = 0.01 ), intensively drug resistance rate was 5.8% (7.0% vs. 4.7%; p = 0.07 ), and no pan drug resistance has been identified. Conclusion. Bacterial resistance to antibiotics of clinical relevance in Cameroon was high and appeared to increase between 2010 and 2017. There is a need for regular surveillance of antibacterial resistance to inform public health strategies and empirically inform prescription practices.</jats:p