Molecular Characterization of the Circulating Strains of Vibrio cholerae during 2010 Cholera Outbreak in Nigeria.

This study aimed at characterizing the phenotypic and toxigenic status of circulating strains of cholera during outbreaks in Nigeria, employing molecular typing techniques. Two hundred and one samples of rectal swabs, stool, vomitus, water (from the well, borehole, sachet, stream, and tap) and disinfectants (sodium hypochlorite) were collected from three states in the country. The samples were inoculated on thiosulphate-citrate bile salt-sucrose (TCBS), Cary-Blair transport medium and smeared on glass slides for direct examination. The Vibrio cholerae isolates were serotyped, biotyped, and characterized using PCR of the cytotoxin gene A (ctxA), wbeO1, and wbfO139 gene primer. Of the 201 samples screened, 96 were positive for V. cholerae O1 (48%), with 69 (72%) positive for ctxA gene. The results from this study showed that the circulating strains of cholera in Nigeria were of Ogawa serotype, also observed in other outbreaks in Nigeria (1991, 1992, and 1996). However, the strains were of the Classical biotype and were mainly (72%) ctxA gene-positive. This current investigation has confirmed the production of cholera toxin by the circulating strains, and this could be harnessed for possible cholera vaccine production in Nigeria.

Chlamydia and Vaginitis in Sexually Active Females: Classical Identification Methods for Effective Control

Laboratory diagnosis of Chlamydia and vaginitis in sexually active females has been limited by unavailability of a sequential method/rapid technique for simple diagnosis. Six hundred (600) adult females from hotel/brothel; Sexually Transmitted Infections (STIs) Clinic; Obstetrics/Gynaecology Clinic; Family Planning Clinic and Healthy controls were investigated for Chlamydia; Candida; trichomoniasis and bacterial vaginosis (BV). This was done using microscopy: wet mount; stained vaginal secretion and stained smear after culture. Results showed that there were 72infections in the female groups. The brothel and STI group had infection in the range (70-86). Chlamydial infection was highest in the STI group while Candida infection was highest in the healthy (control) females. Bacterial vaginosis was distributed in all groups. As p-value increased; f-value increased indicating constant co-infection of Candida and BV in Chlamydia positive females. Microscopy by direct detection from sample and stained smear after culture were in the range: 56-86. Direct microscopy for BV was 78.5and stained smear after culture; 57.1. Sensitivity and specificity of the techniques showed that detection of Chlamydia was less sensitive by direct microscopy of sample but sensitivity and specificity of stained smear after culture were high. Immunoassay (32.2) was also less sensitive. Sensitivity and specificity of wet mount microscopy for Candida; Trichomoniasis and BV were in the range 62.5 - 80and 62.5-97.8respectively. Wet mount has high sensitivity and specificity for detecting agents of vaginitis and may be useful for routine use and for diagnosis where disease is absent; thus; making identification more cost effective

Associated risk factors and pulsed field gel electrophoresis of nasal isolates of Staphylococcus aureus from medical students in a tertiary hospital in Lagos, Nigeria

Staphylococcus aureus infections are growing problems worldwide with important implications in hospitals. The organism is normally present in the nasal vestibule of about 35 percent of apparently healthy individuals and its carriage varies between different ethnic and age groups. Staphylococcal nasal carriage among health workers is particularly important to establish new clones and track origin of infections during outbreak situations. To determine the carriage rate and compare the pulsed field gel patterns of the strains, nasal swabs were collected from 185 medical students in a teaching hospital in Lagos, Nigeria. Isolates of S. aureus were tested for heamolysin production, methicillin sensitivity and Pulsed Field Gel Electrophoresis (PFGE) was performed. The results showed S.aureus nasal carrier rate of 14 percent with significant rate among males compared to females. All the isolates produced heamolysin. Antibiotic susceptibility pattern revealed that majority of the isolates was susceptible. Five strains (19 percent) harboured resistant determinants to penicillin and tetracycline. None of the strains was resistant to methicillin. 44 percent of the isolates typed by PFGE had type B, the most predominant pulsotype. PFGE A clone exhibited a single resistance phenotype suggesting a strong clonal relationship that could punctual an outbreak in the hospital. The results speculate that nasal carriage among medical personnel could be a function of various risk factors. Personal hygiene and behaviour may however be the means to reducing colonization and spread of S.aureus in our hospitals.