[Show abstract][Hide abstract] ABSTRACT: 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.
Full-text · Article · Jun 2013 · Journal of Health Population and Nutrition
[Show abstract][Hide abstract] ABSTRACT: This study investigated the levels of prepatent S. haematobium infection in water samples collected from Schistosomiasis haematobium transmission namely: International Institute of Tropical Agriculture (IITA) river and Eleyele river in Oyo state, Oyan dam and Shokori river in Ogun state, Badagry Lagoon and Lagoon (University of Lagos, Lagos state).
Polymerase chain reaction (PCR) assay amplifying the Dra I repeated sequence of S. haematobium cercariae from the water samples was used. Samples of cercariae obtained from a laboratory population of Bulinus globosus and Bulinus rohlfsi snails were assayed following DNA extraction as control. Physico-chemical parameters of the water bodies were determined.
Physico-chemical parameters showed that salinity, conductivity and total dissolved solids were relatively high in the Lagoon front samples (41.91 ppt, 62400.87 micros/cm, 31000.14 mg/L and 7.79), and low in the river samples (13.27 ppt, 1325.67 micros/cm, 11470 mg/L and 8.36 respectively) while pH were similar. PCR showed that 3 out of the 6 water bodies sampled namely IITA river, Eleyele river and Oyan Dam are S. haematobium endemic sites as they gave positive signals.
Three surveyed sites with relatively low salinity namely IITA river, Eleyele river and Oyan dam are high S. haematobium endemic areas and schistosomes survive perhaps best in low salinity environment. PCR could be a more valuable tool in the study of incidence and prevalence of S. haematobium infection compared with conventional cercariae shedding method. On the known strength of focal effects of environmental conditions, implications of these results in the epidemiology and design of control activities are encouraging.
No preview · Article · Dec 2012 · African journal of medicine and medical sciences
[Show abstract][Hide abstract] ABSTRACT: The 2010 cholera outbreak in northern Nigeria affected over 40,000 people, with a case fatality rate (CFR) of ≥3.75%. We assessed the emergency response of health care workers (HCWs) involved in case management.
This was a cross-sectional study with data collected through a self-administered questionnaire. Data entry and analysis were performed using Epi info software.
A total of 56 HCWs were interviewed. The mean age was 31 years (SD±8.16 years). The majority of the HCWs (80%; n=45) were aged 18-39 years. Most were community health extension workers (60%), and 3.6% (n=2) were medical doctors. Many of the HCWs had less than 2 years of work experience (42%). Additionally, 82% of the respondents had <1 week of cholera emergency response training, and 50% of the HCWs managed >20 suspected cases of cholera per day. Although 78% of HCWs reported the practice of universal safety precautions, 32% (n=18) knew HCWs who developed symptoms of cholera during the epidemic, most of which was believed to be hospital acquired (78%). We also found that 77% (n=43) of HCWs had no access to the required emergency response supplies.
Inadequate training, a lack of qualified HCWs and a limited supply of emergency response kits were reported. Therefore, the government and stakeholders should address the gaps noted to adequately control and prevent future epidemics.
[Show abstract][Hide abstract] ABSTRACT: Food borne Salmonella infection is an important cause of morbidity and mortality. A total of 200 food samples commonly sold in Lagos, Nigeria comprising raw and cooked meat as well as meat products and spoilt meat were analysed for the presence of Salmonella spp using REVEAL serology kit, culture methods employing RPVA (Rappaport Vassiliadis agar), SSA (Salmonella-Shigella agar) and BSA (brilliant sulphite agar) and PCR method for direct detection from samples using primer salm3/4 and ST11/ST15 sets. Using the REVEAL serology kit, 74% of the samples were positive for Salmonella spp, while culture methods showed only 19% to be Salmonella spp. The PCR method revealed that Salmonella spp was present in 62% and 54% of the samples using primer set salm3/4 and ST11/ST15, respectively. However, the primer set ST11/ST15 was more reliable in the identification of Salmonella spp directly from food samples. These tools should prove useful in the continuous monitoring and control strategies especially for ready-to-eat foods, as well as in retail meat outlets, slaughter houses, fast food restaurants for the prevention and reduction of this pathogen that is of significant importance in the food industry.
Full-text · Article · May 2012 · The Southeast Asian journal of tropical medicine and public health
[Show abstract][Hide abstract] ABSTRACT: There is an urgent need for affordable point-of-care diagnostics for the differentiation of febrile illnesses and the confirmation of typhoid in endemic countries.
Blood samples were collected from febrile patients with clinical suspicion of typhoid and screened for typhoid fever using the Widal and Typhi Dri Dot tests, while stool and blood samples were screened for Salmonella Typhi using the culture method as well as PCR as a confirmatory test.
A high proportion of febrile patients from Lagos with clinical suspicion of typhoid fever reacted positively in a simple and rapid latex agglutination assay for typhoid fever, indicating that this illness is a common and presumably under-diagnosed health problem in this metropolis. Seropositivity was 19.2% in the rapid test compared with 22.9% in the classical Widal test. The confirmation of typhoid in these seropositive patients appeared cumbersome because of negative blood cultures and low DNA yield in molecular testing. A review of the literature revealed that in Nigeria seroprevalence rates can be high in the normal population and that pathogens other than S. Typhi are often isolated from the blood of seropositive febrile patients.
The simplicity and the relatively high specificity (97.8%) of the rapid test as determined in a study performed in Indonesia calls for a further validation of this promising test for use in Africa.
Full-text · Article · Jul 2011 · The Journal of Infection in Developing Countries
[Show abstract][Hide abstract] ABSTRACT: The study was aimed at comparing PCR methods of direct detection from biopsy using the boiling method and one other method with two known gold standards (histology and CLO test) for the diagnosis of H. pylori in Nigeria. A total of 168 biopsies (three from antrum and one from corpus each) were taken from 42 patients presenting with various gastroduodenal symptons after informed consent was obtained from them.The biopsies were analysed using the CLO test kit and histology, while the boiling method as described by Holmes and Quigley (1981) was used to obtain DNA and then PCR using the 16S rRNA gene, glmM gene and cagA gene. With CLO test 15/42 (35.71%) were positive, histology 13/42 (30.95%) were positive, 16S rRNA 22/42 (52.38%) were positive, glmM 19/42 (45.24%) were positive, cagA 19/42 (45.24%) were positive. The sensitivity and specificity of the PCR tests with CLO as the gold standard showed that the tests were 100% sensitive and varied between 74.1% to 84.1% in specificity. The PPV and NPV showed that the NPV was almost 100%, while the PPV was between 68.2% and 75%. Using the histology as the gold standard, the sensitivity was almost 100% while the specificity, the PPV were reduced in comparison to the CLO test. The PCR test using the glmM gene appears to be the most reliable test for diagnosis of H. pylori in Nigeria most especially where culture is difficult due to the power outages.
Full-text · Article · Jan 2011 · International Journal of Molecular Epidemiology and Genetics
[Show abstract][Hide abstract] ABSTRACT: Purpose: Food handlers play an important role in the
transmission of typhoid bacilli and other Salmonella spp. This study was conducted to determine the prevalence and antimicrobial resistance patterns of Salmonella spp. from food handlers and cattle and compare the patterns with specimens from patients. Methods: A total of 206 stool samples from apparently healthy food handlers from bukkas (cafeteria) and 100 stool samples from cattle were collected in Lagos Metropolis between June 2006 and June 2007. The prevalence and susceptibility patterns of the S. typhi isolates from the samples and those obtained from the stool samples of 27 patients were determined.
Results: Salmonella species isolated from the stool samples collected from food handlers were S. typhi, S. enteritidis, S. choleraesuis, S. paratyphi A and S. arizona with prevalence of 6.8%, 5.3%, 2.9%, 1.5% and 0.5%, respectively. S. enteritidis and S. typhimurium were isolated from 100 faecal cattle samples with prevalence of 12% and 3%, respectively. Nearly all the isolates (including the clinical isolates) were sensitive to nitrofurantoin, nalidixic acid, and ofloxacin, while
all were sensitive to ciprofloxacin. Conclusion: Food handlers working in bukkas (cafeteria) and cattle are possible reservoirs of Salmonalle species in Lagos. Other than fluoroquinolones, Salmonalle species exhibit high levels of resistance to most antibiotics.
Keywords: Salmonella species; Food handlers; Cattle,
Antibiotic resistance; Lagos.
[Show abstract][Hide abstract] ABSTRACT: Problem statement: Crude oil which may be broadly characterized as paraffinic or naphthenic is a complex mixture of alkanes, cycloalkanes and aromatic hydrocarbons. About 500,000 workers are employed in crude oil exploration and production worldwide. There have been reports of occupational exposure during drilling, pumping and transportation of crude oil, including maintenance of equipment used for these processes. Thus, skin tumors have been reported in mice after repeated application of the east Wilmington crude oil to their skin. Approach: It may thus be necessary to investigate the mutagenic potentials of crude oil fractions using a modified Ames test and internationally accepted Allium cepa (Linn) assay. The Allium cepa assay was done to determine the mean root length, mitotic index and chromosomal aberrations of the onions root grown in various concentrations of 5, 10 and 15% v / v crude oil, petrol, kerosene, engine oil and diesel in water. The modified Ames test which is a modification of the standard Ames test was done using E. coli (0157: H7) that has the phenotypic characteristics of glucose and lactose fermentation, motile, urease negative, indole positive and citrate negative. Thus the alteration in normal biochemical characteristics was determined by inoculating the revertant strains produced by the organism after incubating with the crude oil fractions into the specified media to re-determine their biochemical characteristics. Results: The results obtained from the Allium cepa assay showed increasing root growth inhibition with increased concentration and decreasing mitotic index with increased concentration. Stickiness, Vagrant, Bridges and fragments, Bi-nuclei, C-mitosis, multi polar anaphase and anaphase with laggards chromosomal aberration were observed. The modified Ames test showed a remarkable alteration in the biochemical characteristics of E. coli (0157: H7) by petrol and engine oil indicating mutagenicity. Conclusion: The results of the Ames test showed petrol and engine oil to demonstrate mutagenicity in bacteria, while, the Allium cepa assay showed mitodepressive effects of crude oil, petrol, engine oil, diesel and kerosene.
Full-text · Article · Mar 2010 · American journal of pharmacology and toxicology
[Show abstract][Hide abstract] ABSTRACT: Increasing concern has been expressed about the possible declining trend in the sperm quality and sperm count of man as a result of exposure to environmental estrogenic agents in the past few years now. There is a general paucity of knowledge of BLCO ingestion on the reproductive effect. Hence, we aim to evaluate the impact of sub-lethal dose of BLCO ingestion on semen parameters of adult male mice. Initial acute toxicity study was carried out to determine the lethal dose of BLCO, which was calculated to be 37.4 mg/Kg body wt. A sub-lethal dose of 20 mg/Kg bwt /day of BLCO were then given to 8 male mice in the experimental group. While,the control group of 7 animals received equal volume of 0.9% normal saline via oral garvage for 2 weeks. Data were analysed using SPSS 12 statistical software with P >0.05 considered statistically significant. There was a significant (P >0.05) weight gain in the treated group with a significant (P >0.05) reduction in sperm motility in the treated compared with control. The sperm density of treated and control were 14.5 × 106ml and 20.5 × 106 /ml respectively. However, there were also no significant difference in the relative testicular weight and sperm density of treated from that of the control respectively. Thus, it was concluded that BLCO ingestion is spermatotoxic in the adult male Swiss mice
Preview · Article · May 2009 · International journal of physical sciences
[Show abstract][Hide abstract] ABSTRACT: Objective: Prevalence, antibiotic patterns and plasmid profiles of Enterohaemorrhagic Escherichia coli (EHEC) 0157:H7 from humans and environmental sources were studied at various seasons of the year in Nigeria. Methodology: Stool and environmental samples were obtained from Lagos and Zaria and characterized as EHEC 0157:H7 using the method of Cowan and serotyping. The isolates were further characterized using antibiotic susceptibility testing and plasmid profile. Results: Out of 132 stool samples, 42 (31.8%) of EHEC 0157:H7 were isolated between April to December 2004. These samples were from Lagos (Western Nigeria) and Zaria (Northern Nigeria). Thirty-three isolates were from Lagos while 9 were from Zaria. Out of 90 environmental samples, 11 (12.2%) were positive for EHEC 0157:H7. The highest number of isolates (13) was obtained during the month of December, the dry, harmattan and festive season. Most of the isolates from Zaria were resistant to ampicillin, nitrofurantoin and tetracycline, while those from Lagos were resistant to ampicillin, cotrimoxazole, nitrofurantoin and tetracycline. Nine out of 53 (17%) isolates harboured detectable plasmids. Conclusion: The presence of multi-drug resistance amongst these isolates is of concern and so antibiotic therapy should not be recommended as it complicates the disease while misuse in our environment has led to emergence of resistance strains.
No preview · Article · Apr 2009 · Pakistan Journal of Medical Sciences Online
[Show abstract][Hide abstract] ABSTRACT: Microorganisms are transferred to everyday objects from the environment and infected individuals. Pathogenic microbes are transmissible from the air, skin, hands and other interpersonal contacts and cause diseases most of the time. This study centres on the microbial assessment of telephone receivers, their ability to transfer bacterial infections and the isolation of these microorganisms from receivers, with an emphasis on Staphylococcus aureus and its antibiotic susceptibility pattern.
1,591 isolates were obtained from roadside telephone booths in 16 different locations in the Lagos metropolis. They were all characterised using the Cowan and Steel's manual, after which the antimicrobial susceptibility pattern of the most frequently-occurring isolate was determined.
Of all the locations, Oshodi was found to have the largest number of microorganisms, with Akoka having the least. The organisms were Providencia, Klebsiella, Citrobacter, Enterobacter, Proteus, Escherichia, Staphylococcus, Bacillus, Streptococcus, Micrococcus and yeast. Staphylococcus spp. was the most frequently occurring, making up 20.2 percent of the total number of isolated organisms, followed by Bacillus (18 percent), while Enterobacter and Citrobacter were the least common. 44 percent of the total Staphylococcus screened for an antimicrobial susceptibility pattern showed high resistance to most of the antibiotics used.
This result could be related to the emergence of Staphylococcus-resistant strains, especially in a highly-populated area where there are health and hygiene problems and where drugs are abused. Precautions should be taken to prevent the spread of infectious diseases through the use of public telephones.
Full-text · Article · Mar 2009 · Singapore medical journal
[Show abstract][Hide abstract] ABSTRACT: In order to reduce the incidence of foodborne disease which constitutes a major public health problem, we are focussing our attention on the exploitation of indigenous food grade lactic acid bacteria to improve the safety and hygiene of fermented products. In this study we isolated lactobacilli from four fermented dairy products and screened them for the production of antimicrobial substances by eliminating the effects of organic acids and hydrogen peroxide. Three foodborne bacterial pathogens, enterotoxigenic Escherichia coli (ETEC), Salmonella typhimurium and Listeria monocytogenes were used as indicators. Of the twelve Lactobacillus isolates obtained, six showed antagonistic effects against at least one of the pathogens. Three of the twelve isolates (one with detectable antimicrobial activity and two without) were found to harbour plasmids. Plasmid elimination by curing with ethidium bromide revealed no association between the antimicrobial activity and the plasmids. With these results it may be assumed that the antimicrobial effects of these isolates on the pathogens investigated were determined by their chromosomes. In conclusion we have identified indigenous strains of food grade lactobacilli with antimicrobial activity against clinically important bacterial enteropathogens.
Preview · Article · Feb 2008 · Biotechnology(Faisalabad)
[Show abstract][Hide abstract] ABSTRACT: A high salt diet can elevate blood pressure in humans and other susceptible animal species. A high proportion of our indigenous foods are fermented products and
Lactobacillus species have been reported to be the predominant flora in many of our indigenous fermentation processes. In this study, the effect of concurrent oral
administration of a yoghurt (produced by fermenting skimmed milk with a strain of L. acidophilus isolated from an indigenous fermented food) on salt loaded male
Sprague-Dawley rats was investigated. The acidophilus yoghurt was found to prevent the development of hypertension in the salt loaded rats (p<0.05) without significant changes in heart rate, plasma Na+, Cl-,HCO3- levels. This shows a potential application of Lactobacillus derived probiotics in the prevention of cardiovascular disease risk factor.
[Show abstract][Hide abstract] ABSTRACT: Nosocomial infections caused by methicillin-resistant strains of Staphylococcus aureus constitute significant epidemiologic problems. Defining an outbreak requires the use of rapid and highly discriminatory epidemiologic methods to determine the epidemic strains involved in such outbreak.
A descriptive laboratory based surveillance study for MRSA was undertaken. One hundred and forty seven Staphylococcus aureus isolates from clinical specimens were screened for methicillin resistance at the University of Ilorin Teaching Hospital between January and December 2001. Fifty one (34.7%) methicillin resistant strains recovered were epidemiologically characterized using Eco R1 restriction enzyme analysis of their plasmid DNAs.
Forty five (88.2%) MRSA isolates were associated with infections and 6 (11.8 %) were colonizing strains; 36 (70.6%) and 15 (29.4%) were hospital and community acquired respectively. Skin and soft tissues were sites of infection in 36 (70.6 %) cases and surgical, emergency and ICU accounted for 33 (64.7%) isolates. All isolates were resistant to more than two antibiotics but sensitive to vancomycin. Forty two (82.4 %) isolates contained plasmids including 9 (21.4 %) that contained more than one plasmid. Restriction Enzyme Analysis of the Plasmid DNA (REAP) divided the isolates into 9 Eco R1 profiles, with profile 2 accounting for 41.7% of all nosocomial infections in the wards, implying that it is endemic. The remaining nosocomial profiles occurred less frequently, suggesting that they are sporadic strains originating from outside the hospital. The community strains showed diverse digestion pattern indicating that they are from different clones.
The spread of MRSA can be controlled through reinforcement of appropriate use of antibiotics, hand washing and laboratory surveillance for MRSA, particularly in the surgical wards and intensive care units, in order to identify sources of outbreaks.
Full-text · Article · Oct 2005 · West African journal of medicine
[Show abstract][Hide abstract] ABSTRACT: Four Nigerian medicinal plants commonly used in the treatment of bacterial infections were tested for antimicrobial activity against twenty local strains of Helicobacter pylori recovered from patients with gastro-duodenal ulcers and gastritis. In vitro agar diffusion assay revealed anti-Helicobacter pylori activity of ethanolic extracts of C. papaya and M. lucida to 80% (16/20) of the isolates tested, while the ethanolic extracts of O. gratissimum and P. amarus inhibited the colonial growth of 35% (7/20) of these strains. The zones of inhibition ranged from 5 – 20 mm in diameter. Contrastingly, the aqueous extracts of these plants appeared to lack anti-Helicobacter pylori activity except in M. lucida and O. gratissimum where inhibition of a total of three isolates was observed. The present results suggest the presence of anti-Helicobacter pylori principles in ethanolic extracts of C. papaya and M. lucida and support their future use in the treatment of ulcers and gastritis in Nigeria.
(Af J Clinical & Exp Microbiology: 2003 4(2): 29-35)
Full-text · Article · Feb 2003 · African Journal of Clinical and Experimental Microbiology