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 < 0.01), 3rd generation-resistant Enterobacteriaceae (23.8% vs. 40.4%, +65.8%, p < 10-15), methicillin-resistant Staphylococcus aureus (27.3% vs. 46.0%, +68.6%, p < 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 < 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.

Epidemiology of methicillin-resistant Staphylococcus aureus lineages in five major African towns: emergence and spread of atypical clones.

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Africa is poorly documented. From January 2007 to March 2008, we collected 86 MRSA isolates from five African towns, one each in Cameroon, Madagascar, Morocco, Niger and Senegal. Although one or two major clones, defined by the sequence type and staphylococcal cassette chromosome mec type, predominated at each site, genetic diversity (ten clones) was relatively limited in view of the large geographical area studied. Most of the isolates (n = 76, 88%) belonged to three major clones, namely ST239/241-III, a well-known pandemic clone (n = 34, 40%), ST88-IV (n = 24, 28%) and ST5-IV (n = 18, 21%). The latter two clones have only been sporadically described in other parts of the world. The spread of community-associated MRSA carrying the Panton-Valentine leukocidin genes is a cause for concern, especially in Dakar and possibly throughout Africa.

[Fatal miliary tuberculosis in an HIV-infected Cameroon woman: disseminated histoplasmosis due to Histoplasma capsulatum capsulatum]. / Miliaire pulmonaire létale chez une femme camerounaise infectée par le VIH.

The purpose of this report is to describe the first Cameroonian case of disseminated histoplasmosis due to Histoplasma capsulatum capsulatum in association with HIV infection. The patient was a 34-year-old HIV1 infected woman. Diagnosis of histoplamosis was made in post-mortem. The similarity of the clinical symptoms with disseminated tuberculosis makes diagnosis of mycosis difficult. Active and effective care of histoplasmosis is urgently necessary for the HIV infected persons.

Epidemiology of methicillin-susceptible Staphylococcus aureus lineages in five major African towns: high prevalence of Panton-Valentine leukocidin genes.

The epidemiology of methicillin-susceptible Staphylococcus aureus (MSSA) in Africa is poorly documented. From January 2007 to March 2008, 555 S. aureus isolates were collected from five African towns in Cameroon, Madagascar, Morocco, Niger, and Senegal; among these, 456 unique isolates were susceptible to methicillin. Approximately 50% of the MSSA isolates from each different participating centre were randomly selected for further molecular analysis. Of the 228 isolates investigated, 132 (58%) belonged to five major multilocus sequence typing (MLST) clonal complexes (CCs) (CC1, CC15, CC30, CC121 and CC152) that were not related to any successful methicillin-resistant S. aureus (MRSA) clones previously identified in the same study population. The luk-PV genes encoding Panton-Valentine leukocidin (PVL), present in 130 isolates overall (57%), were highly prevalent in isolates from Cameroon, Niger, and Senegal (West and Central Africa). This finding is of major concern, with regard to both a source of severe infections and a potential reservoir for PVL genes. This overrepresentation of PVL in MSSA could lead to the emergence and spread of successful, highly virulent PVL-positive MRSA clones, a phenomenon that has already started in Africa.

Enteroaggregative Escherichia coli: a public health hazard in Yaounde; Cameroon?

The prevalence of various pathotypes of Escherichia coli was investigated during a case-control study conducted in children diarrhoea in Yaounde. Isolates obtained from the stools samples of children aged 6 months to 5 years were selected on phenotypic basis; and identified by virulence genes detection using polymerase chain reactions. The most prevalent pathotype was enteroaggregative Escherichia coli (25.8). Enteropathogenic Escherichia coli (3.6); enterotoxigenic Escherichia coli (1); and enteroinvasive Escherichia coli (0.2) followed. No shiga toxin-producing Escherichia coli were identified. Enteroaggregative Escherichia coli was not associated with diarrhoea (cases 26.1; controls 25.5; P=0;887); unlike enteropathogenic Escherichia coli (cases 6.7; controls 1; P=0.003). Investigations into documented potentials of enteroaggregative Escherichia coli in causing diarrhoea and other related pathologies indicated that it could be a major public health threat in Cameroon despite the fact that it was not found associated with clinical diarrhoeal cases in this study

[Antibiotic susceptibility of Vibrio cholerae 01: evolution after prolonged curative and preventive use during the 2004 cholera epidemics in Douala (Cameroon)]. / Evolution de la sensibilité de Vibrio cholerae 01 après utilisation prolongée d'antibiotiques en traitement et en prophylaxie au cours de l'épidémie de choléra de Douala (Cameroun) 2004.

UNLABELLED: Antibiotics were extensively used, both for curative as for prophylactic purposes, to prevent an explosive spread of the 2004 cholera epidemic in Douala. It was thus necessary to control the antibiotic susceptibility of Vibrio cholerae. OBJECTIVE: The authors had for aim to describe the epidemic, the use of antibiotics, and to follow the susceptibility of V. cholerae. DESIGN: The 14 hospitals in the study all used the same diagnostic, treatment, and preventive protocols, as well as in community practice with home visits. All cases were clinically confirmed and reported. Samples were systematically taken at the beginning and at the end of the epidemic, and randomly during the epidemic. Each identified strain was tested by the disk method for antibiotic susceptibility. RESULTS: Between January and September 2004, 5013 patients and 177,353 people in contact with the patients were given a single dose of doxycycline or amoxicillin for 3 days. Sixty-nine deaths were recorded (lethality 1.37%). One hundred (and) eleven strains of V. cholerae were identified in 187 samples. All of them were resistant to sulfamides and colistin, but susceptible to cyclins, betalactams, and fluoroquinolones, without any modification during the 8 months of follow-up. CONCLUSION: Despite the risk of a massive and prolonged use of antibiotics, strictly prescribed and controlled, no resistance developed in the identified strain. Chemoprophylaxis must follow rigorous protocols and be continuously monitored.

Routine use of antimicrobial drugs during the 2004 cholera epidemic in Douala, Cameroon.

OBJECTIVES: To evaluate routine use of antimicrobial drugs for treatment and prevention of cholera with special regards to the evolution of the antimicrobial drug resistance patterns of V. cholerae strains. DESIGN: Retrospective population-based descriptive study. SUBJECTS: Four thousand nine hundred and forty one notified cholera cases, their 15,381 patients' guards and their 159,263 household members and close neighbours. RESULTS: A total of 4,941 patients received antibiotic therapy according to the treatment protocols. Prophylactic treatment was administered to 15,381 patients' guards in hospitals and to 159,263 household members and close neighbours during home visits. Over the entire outbreak, the antimicrobial susceptibility patterns of V. cholerae strains isolated remained stable. CONCLUSIONS: The routine use of antimicrobial therapy for cholera cases associated with simultaneous and large scale chemoprophylaxis of close contacts does not seem in our experience to compromise the stability of V. cholerae susceptibility profiles to drugs when applied within a comprehensive package of rigorously monitored community interventions. The role of therapy and chemoprophylaxis in limiting the extent of a cholera epidemic is however difficult to ascertain from our experience. Field trials need to be designed to elucidate this aspect.

[Bacterial meningitis in Yaoundé (Cameroon) in 1999-2000]. / Les méningites d'étiologie bactérienne à Yaoundé (Cameroun) en 1999-2000.

All cephalo-spinal fluid (CSF) samples sent to the Yaoundé Pasteur Centre in Cameroon, between July 1999 and June 2000, were cultured and tested for soluble antigens. The percentage of positive samples was 10.4%. The main etiological agents detected were Streptococcus pneumoniae (56.2%), Haemophilus influenzae (18.5%) et Neisseria meningitidis (13.4%). Most of these cases of bacterial meningitis were children (86.7%). The susceptibility of the isolates to antibiotics was investigated. The streptococci and meningococci were mostly susceptible to beta-lactams, but the Gram-negative bacteria were not. Combinations of amino-penicillin and aminoside or chloramphenicol continue to be effective, as are third generation cephalosporins used alone. Meningococci appear to have emerged during the year 1999/2000, with 23 such isolates identified, of which 17 were serogroup A, subtype P1-9, clone III-1, which was responsible for the second pandemic. It should also be noted that 4 strains of N. meningitidis of serogroup W135 were isolated in Yaoundé.

[Analysis of 190 strains of Neisseria gonorrhoeae isolated in Yaounde from 1984 to 1987: auxotypes, plasmidic contents, antibiotic sensitivity]. / Analyse de 190 souches de Neisseria gonorrhoeae isolées à Yaoundé de 1984 à 1987: auxotypes, contenus plasmidiques, sensibilité aux antibiotiques.

Gonococcal infections are always a public health problem in Cameroon. From January 1984 to December 1987, 2,074 strains have been isolated in the "Centre Pasteur du Cameroun". Among these strains, 190 had been studied in details concerning antibiotic susceptibility, auxotypes and plasmidic content. Penicillinase producing Neisseria gonorrhoeae (PPNG) were increasingly isolated: 32.28% (1984); 59.57% (1987). Auxotypes prototrophes and proline requiring were more often isolated. Plasmidic content showed essentially african type (with or without conjugative plasmid) but also asian type.

[Antibiotic resistance of strains of Vibrio cholerae eltor isolated in Douala (Cameroon)]. / Résistance aux antibiotiques des souches de Vibrio cholerae eltor isolées à Douala (Cameroun).

Endemic cholera has been prevalent in Douala since 1972, with sudden epidemic outbreaks occurring every two years during the dry season. The massive and systematic use of chemoprophylaxis since April, 1983 has led to the selection of strains of Vibrio cholerae eltor that are resistant to sulphamide and tetracycline. During the 1984-1985 epidemic, 89.3% of the isolated strains were resistant to sulphamides, 87.5% to a sulfamethoxazole-trimethoprim combination and to the 0/129 disk, 55.3% to tetracycline, 91.1% to chloramphenicol, 73.2% to streptomycin and 94.6% to ampicillin. The epidemic aspect of this multiple resistance to antibiotics raises the issue of the role of a group C incompatibility resistance plasmid. As regards prophylaxis, until hygiene conditions can be improved, which is the only way cholera can be eradicated from our region, vaccination with oral vaccines such as that of the Institut Pasteur seems to be the best way of preventing further epidemics.