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Helicobacter pylori (H. pylori) infection is ubiquitous worldwide, with prevalence rates of greater than 70% in Africa. Symptomatic patients present with foregut gastrointestinal symptoms which can be readily diagnosed with standardized non-invasive or invasive tests. The biggest challenge, however, is in the management of this condition with rising antimicrobial resistance rates to most of the antibiotics recommended for therapy. This is a problem worldwide, but more specifically in Africa, where the socio-economic and political climate is such that eradication of this organism seems impossible. Furthermore, the recommended antimicrobial susceptibility testing for drug resistance is not widely available in Africa due to the lack of infrastructural as well as human resources. With the widespread unregulated use of antibiotics in some parts of Africa, the figures of antimicrobial resistance are likely to soar. In the face of these significant challenges, this ‘perspectives’ article aims to address the issue of antimicrobial resistance in Africa, by providing achievable and targeted goals to curb the spread of infection and rising antimicrobial resistance.

The global evolution of antibiotic resistance has threatened the efficacy of available treatment options with ravaging impacts observed in developing countries. As a result, investigations into the prevalence of antibiotic resistance and the role of plasmids are crucial. In this study, we investigated the presence and distribution of blaTEM and gyrA genes, plasmid profiles, and the antimicrobial susceptibility pattern of Salmonella strains isolated from raw meat and stool sources across Niger State, Nigeria. Ninety-eight samples, comprising 72 raw meat and 26 stool samples, were screened for Salmonella spp. The antimicrobial susceptibility of Salmonella isolates to 10 commonly used antimicrobial agents was determined using the Kirby- Bauer disc diffusion method. Isolates were further analyzed for plasmids, in addition to PCR amplification of beta-lactamase (blaTEM) and gyrA genes. A total of 31 Salmonella spp. were isolated, with 22 from raw meat (70.97%) and 9 from stool (29.03%). Salmonella spp. with multiple resistance patterns to ceftazidime, cefuroxime, ceftriaxone, erythromycin, ampicillin, cloxacillin, and gentamicin were detected. Ofloxacin and ciprofloxacin were found to be the most effective among the antibiotics tested, with 67.7% and 93.5% susceptible isolates, respectively. Nine (29.03%) isolates harbored plasmids with molecular sizes ranging between 6557 bp and 23137 bp. PCR amplification of gyrA was detected in 1 (3.23%) of the 31 isolates while 28 isolates (90.32%) were positive for blaTEM. This study shows the incidence of antibiotic resistance in Salmonella isolates and the possible role of plasmids; it also highlights the prevalence of ampicillin resistance in this local population.

The medicinal plant Spathodea campanulata P. Beauv. (Bignoniaceae) has been traditionally applied for the prevention and treatment of diseases of the kidney and urinary system, the skin, the gastrointestinal tract, and inflammation in general. The present work shows for the first time how chemical components from this plant inhibit Helicobacter pylori growth by urease inhibition and modulation of virulence factors. The crude extract and the main fractions of S. campanulata bark were tested on H. pylori isolated strains and the active ones were further fractionated. Fractions and sub-fractions of the plant crude extract were characterized by ultra-high-performance liquid chromatographic tandem high resolution-mass spectrometry detection (UHPLC-HRMS). Several phenolics and triterpenoids were identified. Among the sub-fractions obtained, SB2 showed the capacity to inhibit H. pylori urease in a heterologous bacterial model. One additional sub-fraction (SE3) was able to simultaneously modulate the expression of two adhesins (HopZ and BabA) and one cytotoxin (CagA). The flavonol kaempferol was identified as the most interesting compound that deserves further investigation as a new hit for its capacity to modulate H. pylori virulence factors.

Outbreaks of Salmonellosis remain a major public health problem globally. This study determined the diversity and antibiotic resistance gene profile of Salmonella enterica serovars isolated from humans and food animals. Using standard methods, Salmonella spp. were isolated from fecal samples, profiled for antimicrobial susceptibility and resistance genes. Seventy-one Salmonella isolates were recovered from both humans and food animals comprising cattle, sheep, and chicken. Forty-four serovars were identified, with dominant Salmonella Budapest (31.8%). Rare serovars were present in chicken (S. Alfort, S. Wichita, S. Linton, S. Ealing, and S. Ebrie) and humans (S. Mowanjum, S. Huettwillen, S. Limete, and S. Chagoua). Sixty-eight percent of isolates were sensitive to all test antibiotics, while the highest rate of resistance was to nalidixic acid (16.9%; n = 12), followed by ciprofloxacin (11.3%; n = 8) and tetracycline (9.9%; n = 8). Five isolates (7%) were multidrug-resistant and antimicrobial resistance genes coding resistance to tetracycline (tetA), beta-lactam (blaTEM), and quinolone/fluoroquinolone (qnrB and qnrS) were detected. Evolutionary analysis of gyrA gene sequences of human and food animal Salmonella isolates revealed variations but are evolutionarily interconnected. Isolates were grouped into four clades with S. Budapest isolate from cattle clustering with S. Budapest isolated from chicken, whereas S. Essen isolated from sheep and chicken was grouped into a clade. Diverse S. enterica serovars with high antibiotic resistance profile are ubiquitous in food animals; hence, there is a need for surveillance and prudent use of antibiotics in human and veterinary medicine.

BackgroundMultidrug resistance efflux pumps and biofilm formation are mechanisms by which bacteria can evade the actions of many antimicrobials. Antibiotic resistant non-typhoidalSalmonellaserovars have become wide spread causing infections that result in high morbidity and mortality globally. The aim of this study was to evaluate the efflux pump activity and biofilm forming capability of multidrug resistant non-typhoidalSalmonella(NTS) serovars isolated from food handlers and animals (cattle, chicken and sheep) in Lagos.MethodsForty eight NTS serovars were subjected to antibiotic susceptibility testing by the disc diffusion method and phenotypic characterization of biofilm formation was done by tissue culture plate method. Phenotypic evaluation of efflux pump activity was done by the ethidium bromide cartwheel method and genes encoding biofilm formation and efflux pump activity were determined by PCR.ResultsAll 48Salmonellaisolates displayed resistance to one or more classes of test antibiotics with 100% resistance to amoxicillin-clavulanic acid. Phenotypically, 28 (58.3%) of the isolates exhibited efflux pump activity. However, genotypically, 7 (14.6%) of the isolates harbouredacrA,acrBandtolC, 8 (16.7%) harbouredacrA,acrDandtolCwhile 33 (68.8%) possessedacrA,acrB,acrDandtolC. All (100%) the isolates phenotypically had the ability to form biofilm with 23 (47.9%), 24 (50.0%), 1 (2.1%) categorized as strong (SBF), moderate (MBF) and weak (WBF) biofilm formers respectively butcsgAgene was detected in only 23 (47.9%) of them. Antibiotic resistance frequency was significant (p ConclusionThese data suggest thatSalmonellaserovars isolated from different food animals and humans possess active efflux pumps and biofilm forming potential which has an interplay in antibiotic resistance. There is need for prudent use of antibiotics in veterinary medicine and scrupulous hygiene practice to prevent the transmission of multidrug resistantSalmonellaspecies within the food chain.

Background Pseudomonas aeruginosa an opportunistic pathogen, is widely associated with nosocomial infections and exhibits resistance to multiple classes of antibiotics. The aim of this study was to determine the antibiotic resistance profile, biofilm formation and efflux pump activity of Pseudomonas strains isolated from clinical samples in Abeokuta Ogun state Nigeria. Methods Fifty suspected Pseudomonas isolates were characterized by standard biochemical tests and PCR using Pseudomonas species -specific primers. Antibiotic susceptibility testing was done by the disc diffusion method. Efflux pump activity screening was done by the ethidium bromide method and biofilm formation assay by the tissue plate method. Genes encoding biofilm formation (pslA & plsD) and efflux pump activity (mexA, mexB and oprM) were assayed by PCR. Results Thirty-nine Pseudomonas spp. were identified of which 35 were Pseudomonas aeruginosa and 4 Pseudomonas spp. All 39 (100%) Pseudomonas isolates were resistant to ceftazidime, cefuroxime and amoxicillin-clavulanate. Thirty-six (92%), 10(25.6%), 20 (51.2%), 11(28%) and 9(23%) of the isolates were resistant to nitrofurantoin, imipenem, gentamicin, cefepime and aztreonam respectively. All the isolates had the ability to form biofilm and 11 (28%) of them were strong biofilm formers. They all (100%) harboured the pslA and pslD biofilm encoding genes. Varied relationships between biofilm formation and resistance to ciprofloxacin, ofloxacin, cefixime, gentamicin, imipenem, and aztreonam were observed. Only 23(59%) of the Pseudomonas isolates phenotypically exhibited efflux pump activity but mexA gene was detected in all 39 (100%) isolates while mexB and oprM genes were detected in 91%, 92%, and 88% of strong, moderate and weak biofilm formers respectively. Conclusion Multidrug resistance, biofilm and efflux pump capabilities in Pseudomonas aeruginosa have serious public health implications in the management of infections caused by this organism.

Background: Staphylococcus saprophyticus is a Gram-positive bacterium implicated in urinary tract infections in sexually active women along with other bacteria. There is a special need to accurately isolate and identify this organism in clinical specimens in order to prevent misidentification in the laboratory. The present study was carried out to evaluate the genetic diversity of one hundred different Staphylococcus saprophyticus strains isolated from women presenting with urinary tract infections reporting in four government hospitals in Lagos Metropolis using 16SrRNA gene sequence analysis. Results: The PCR-amplified and sequenced 16SrRNA gene of 100 isolates and confirmed 88 strains of S. saprophyticus to subspecies level, while 8 belong to other genera and 4 could not be ascertained due to low significant similarity. Phylogenetic analysis showed the interrelationship between the isolates from different hospitals. The results showed the distribution of the isolates into two broad clusters and twenty-two sub-clusters. Conclusion: The results revealed the genetic diversity of Staphylococcus saprophyticus isolated from women with urinary tract infections in Lagos Metropolis using 16SrRNA gene sequence.

Helicobacter pylori is a gram-negative, spiral-shaped bacterial pathogen and the causative agent for gastritis, peptic ulcer disease and classified as a WHO class I carcinogen. While the prevalence of H. pylori infections in Africa is among the highest in the world, the incidence of gastric cancer is comparably low. Little is known about other symptoms related to the H. pylori infection in Africa and the association with certain phenotypes of bacterial virulence. We established a network of study sites in Nigeria (NG) and South Africa (ZA) to gain an overview on the epidemiological situation. In total 220 isolates from 114 patients were analyzed and 118 different patient isolates examined for the presence of the virulence factors cagA, vacA, dupA, their phylogenetic origin and their resistance against the commonly used antibiotics amoxicillin, clarithromycin, metronidazole and tetracycline. We report that H. pylori isolates from Nigeria and South Africa differ significantly in their phylogenetic profiles and in their expression of virulence factors. VacA mosaicism is intensive, resulting in m1-m2 vacA chimeras and frequent s1m1 and s1m2 vacA subtypes in hpAfrica2 strains. Gastric lesions were diagnosed more frequent in Nigerian versus South African patients and H. pylori isolates that are resistant against one or multiple antibiotics occur frequently in both countries.

Objectives The aim of this study was to determine the occurrence of 16S rRNA mutations associated with low-level tetracycline resistance in Helicobacter pylori isolates from adult dyspeptic patients in South West Nigeria. Methods Susceptibility testing to tetracycline of 50 H. pylori isolates was performed by Etest. The 535-bp conserved region of the H. pylori tetracycline-binding site of 16S rRNA was amplified by PCR, followed by sequencing and multiple sequence alignment for all 50 clinical isolates. Results Of the 50 clinical isolates examined, DNA sequence analysis revealed nucleotide substitutions in 7 isolates at positions 926–928. Of the seven isolates, two demonstrated reduced susceptibility to tetracycline with Etest minimum inhibitory concentrations (MICs) of 0.75–1.0 mg/L, whilst the other five isolates were resistant with MICs of 1.5–24 mg/L (resistance breakpoint >1 mg/L). The two isolates with reduced susceptibility had single nucleotide substitution of A926G, whilst the five resistant isolates demonstrated double base pair substitutions of G927T/A928C and A926G/A928C and a single nucleotide substitution of A926G. Conclusions This study shows that low-level tetracycline resistance amongst H. pylori-positive dyspeptic patients is associated with reduced susceptibility and resistance to tetracycline. This is the result of 1-bp and 2-bp differences in positions 926 and 926–928, respectively, in the 16S rRNA of H. pylori.

The sensitivity of 253 Staphylococcus aureus strains isolated from a Nigerian locally-fermented cereal drink (kunun zaki) to 11 antimicrobial agents was determined. Two hundred and forty-seven (97.6%) strains were resistant to one or more of the antimicrobial agents and only 4 (1.6%) isolates were sensitive to all of the agents. Of the isolates from the kunun zaki preparation, 97.8% were resistant while 98.6% from kunun zaki bought at sale outlet and 96.7% of those isolated from utensils were resistant. There was no significant difference in resistance of isolates from the sources (P>0.05, X2). Resistance to penicillin (92.9%), ampicillin (92.9%) and trimethoprim (80.2%) was most frequently encountered while fewer isolates wereresistant to gentamycin (2.0%) and neomycin (3.6%). The predominant antimicrobial resistance pattern was ampicillin-penicillin-trimethoprim detected in 43 (17.0%) strains. The relatively high resistance of S. aureus strains isolated from kunun zaki to the tested antimicrobial agents is suggestive of misuse of those drugs in Nigeria.

This study aimed at comparing the biochemical characterization of Salmonella spp with the molecular typing method. A total of 57 stool samples were collected from three different health institution...

Antibiotic resistance in Helicobacter pylori is a factor preventing its successful eradication. Particularly in developing countries, resistance against commonly used antibiotics is widespread. Here, we present an epidemiological study from Nigeria with 111 isolates. We analyzed the associated disease outcome, and performed a detailed characterization of these isolated strains with respect to their antibiotic susceptibility and their virulence characteristics. Furthermore, statistical analysis was performed on microbiological data as well as patient information and the results of the gastroenterological examination. We found that the variability concerning the production of virulence factors between strains was minimal, with 96.4% of isolates being CagA-positive and 92.8% producing detectable VacA levels. In addition, high frequency of bacterial resistance was observed for metronidazole (99.1%), followed by amoxicillin (33.3%), clarithromycin (14.4%) and tetracycline (4.5%). In conclusion, this study indicated that the infection rate of H. pylori infection within the cohort in the present study was surprisingly low (36.6%). Furthermore, an average gastric pathology was observed by histological grading and bacterial isolates showed a uniform pathogenicity profile while indicating divergent antibiotic resistance rates.

Aim The study is aimed at assessing the knowledge, perception and acceptability of microbicides among non-health care workers in Lagos, Nigeria.

This study focuses on the identification of aetiological agents of vaginitis in Nigerian women. Study subjects are drawn from patients presenting with lower abdominal pain, vaginal discharge and itching at the gynaecology clinic of Lagos University Teaching Hospital and at the Clinical Centre of the Nigerian Institute of Medical Research, Yaba, Lagos, between January 2001 and July 2002. A total of 250 patients gave informed consent to participate in the study. The patients also had pre- and post-test human immunodeficiency virus (HIV) counselling. Each patient completed a questionnaire in order to provide biographical data, past clinical history and socio-economic background information. A cervical swab (CS) and a high-vaginal swab (HVS) were obtained from each patient. Swab samples were examined for pH and under light microscopy by Gram's stain and as wet preparations in 10% potassium hydroxide. Subsequently, samples were cultured on appropriate media at optimal conditions and a drug sensitivity profile for all isolates was determined by standard methods. Blood samples were screened and confirmed for HIV antibodies. Bacterial, fungal and parasitic pathogens were identified or isolated in samples from 241 (96.4%) of the women. Bacterial agents (Neisseria, Streptococcus and Staphylococcus species) were predominant in 128 (51.2%) patients, followed by fungi in 108 (43.2%) and parasites (Trichomonas vaginalis) in five (2.0%). Sensitivity to ciprofloxacin was seen in 40% of Staphylococcus species and in 90% of Neisseria species. Positive HIV serology was seen in 25 (10%) of the 250 women studied, 20 (80%) of which had concurrent microbial infections. Overall, a broad spectrum of microbial agents were shown to be responsible for vaginitis in the group of patients studied.

Helicobacter pylori (Hp) strains that carry the cag type IV secretion system (cag-T4SS) to inject the cytotoxin-associated antigen A (CagA) into host cells are associated with peptic ulcer disease and gastric adenocarcinoma. CagA translocation by Hp is mediated by β1 integrin interaction of the cag-T4SS. However, other cellular receptors or bacterial outer membrane adhesins essential for this process are unknown. Here, we identify the HopQ protein as a genuine Hp adhesin, exploiting defined members of the carcinoembryonic antigen-related cell adhesion molecule family (CEACAMs) as host cell receptors. HopQ binds the amino-terminal IgV-like domain of human CEACAM1, CEACAM3, CEACAM5 or CEACAM6 proteins, thereby enabling translocation of the major pathogenicity factor CagA into host cells. The HopQ-CEACAM interaction is characterized by a remarkably high affinity (KD from 23 to 268 nM), which is independent of CEACAM glycosylation, identifying CEACAMs as bona fide protein receptors for Hp. Our data suggest that the HopQ-CEACAM interaction contributes to gastric colonization or Hp-induced pathologies, although the precise role and functional consequences of this interaction in vivo remain to be determined. published

Microarray-based serogenotyping, antimicrobial susceptibility tests and the detection of relevant resistance genes were performed on isolates of Salmonella spp. from retail meat samples obtained in Lagos, Nigeria. Out of 151 meat samples, 33 Salmonella isolates were obtained. Nine different Salmonella serovars (S. Amoutive, S. Bargny, S. Drac, S. Ealing, S. Urbana, S. Hadar, S. Nyborg, S. Anatum and S. Havana) were identified by microarray-based serogenotyping and confirmed afterwards using classical serotyping. Antibiotic susceptibility tests with 17 antibiotics showed that almost all isolates were fully susceptible to this panel. The results of this study indicated a high prevalence of Salmonella in retail meat, the presence of some previously rather rarely described Serovars in retail meat samples from Lagos, and a need to monitor for Salmonella and their antibiotic resistance determinants. The microarray-based system used herein proved to be perfectly suited as epidemiological tool to replace classical serotyping.

A total of 186 Helicobacter pylori isolates and 532 gastric biopsies recovered from 532 patients with varying degrees of gastroduodenal pathology are subjected to in vitro antibiotic susceptibility testing using the disc-diffusion method, Etest (MIC breakpoints) and molecular testing using the polymerase chain reaction (PCR). In the isolates studied, antibiotic resistance was as follows: piperacillin (72%), amoxicillin (66%), erythromycin (78%), tetracycline (100%) and metronidazole (95%). All isolates were sensitive to ofloxacin, ciprofloxacin and norfloxacin. None of the 245 amplicons (positive for H. pylori) from the biopsies were digested with the Bbs1 and Bsal restriction enzyme used in the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, showing sensitivity to clarithromycin. However, a 238 bp fragment from H. pylori chromosomal DNA (corresponding to the quinolone resistance determining region [QRDR]) of the gyrA gene was amplified successfully. Twelve (4.9%) of the 245 strains studied had the described mutation at position 91, from asparagine (Asn) to glycine (Gly). The study showed that all the H. pylori strains were sensitive to clarithromycin and ciprofloxacin. It also highlighted PCR as a potential tool for faster diagnosis and determination of antibiotic susceptibility (within 24 h) of H. pylori from biopsies and/or isolates recovered from peptic ulcer and gastritis patients.

Four Nigerian traditionally fermented foods (wara, nono, ogi and kunun-zaki) were evaluated for the presence of some microorganisms of public health concern. Among the dairy foods, Staphylococcus aureus and Klebsiella sp. were isolated from wara while Escherichia coli, Salmonella sp. and Klebsiella sp. were isolated from nono. The cereal-based fermented foods (ogi and kunu-zaki) contained Bacillus subtilis, E. coli, S. aureus, Klebsiella sp. and Enterococcus faecalis. The mesophilic aerobic counts were: 5 x 10(5) for wara; nono, 1.53 x 10(7); ogi, 3.6 x 10(6) and kunu-zaki, 2.6 x 10(6) cfu/mL. The enterobacteriaceae counts on nono, wara, ogi and kunu-zaki were 1.79 x 10(7), 4.5 x 10(5), 4.0 x 10(5) and 1.2 x 10(6) cfu/mL, respectively. No Vibrio count (detection limit: < 10 cfu/mL) was recorded in all the food samples considered. The yeast and mold counts ranged from 1.0 x 10(5)-3.31 x 10(7) among the food products. The antimicrobial susceptibility patterns of the organisms isolated from dairy products (nono and wara) revealed that they were resistant to ampicillin (100%) and sensitive to gentamicin (100%) and nalidixic acid (100%). Most isolates from cereal based products (ogi and kunu-zaki) were 100% resistant to penicillin, ampicillin and chloramphenicol. This work highlights the need to maintain hygienic standards in the preparation of our locally fermented cereal and dairy foods.

Seven Lactobacillus species each with one or more strains were isolated from various fermented cereal gruel's (ogi). They were identified as L. plantarum (3 strains), L. delbrueckii (1 strain), L. brevis (2 strains), L. reuteri (2 strains), L. casei (1 strain), L. fermentum (1 strain) and L. acidophilus (1 strain). Bacteriocin production was observed in cell-free supernatants of 8 of these strains with L. fermentum, L. delbrueckii and L. reuteri strains (white maize ogi) being negative. The bacteriocin produced by the eight strains inhibited the growth of various target organisms with the inhibition strongly noticed using Enterococcus faecalis as indicator. While catalase treatment, pH changes and heat treatment up to 80 degrees C had no effect on the activity of bacteriocin from these isolates, treatment with trypsin and proteinase K resulted in complete loss of inhibitory activity of the bacteriocins. A reduction in the inhibitory activity of the bacteriocins was also found to occur with increasing concentrations of glucose or peptone in the cultivation medium.

A total of 228 bacteria with an ability to resist toxic heavy metals were isolated from 8 selected sites of the Lagos Lagoon. The bacteria isolated were Staphylococcus sp., Bacillus sp., Pseudomonas sp., Streptococcus sp., Moraxella sp., Escherichia coli, Proteus sp., Klebsiella sp. and Salmonella sp. The heavy metals to which resistance was recorded were mercury, lead, zinc, cobalt, copper and chromium. The lagoon sites from which the highest number of resistant bacteria were isolated were Marina and Ebute-Ero. The heavy metal to which most bacteria were resistant was cobalt, while the least was chromium. The significance of the result is discussed in relation to the Nigerian environment and human health.

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 ( ctx A), wbe O1, and wbf O139 gene primer. Of the 201 samples screened, 96 were positive for V. cholerae O1 (48%), with 69 (72%) positive for ctx A 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%) ctx A 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. J HEALTH POPUL NUTR 2013 Jun; 31(2): 178-184 DOI: http://dx.doi.org/10.3329/jhpn.v31i2.16381

Cronobacter is a genus with emerging pathogens that has been associated with life threatening diseases in neonates, infants and immunocompromised adults. Three Cronobacter species were isolated from powdered infant formula retailed in Nigeria. Different methods of phenotypic and genotypic characterization were carried out. All the isolates were identified biochemically by Microscan identification analysis as Enterobacter sakazakii (98.87%). The Vitek MALDI-TOF system identified the isolates as Cronobacter sakazakii. 16S rRNA sequencing identified the isolates as C. sakazakii. In contrast the use of species-specific PCR assays targeting rpoB, and cgcA, helped to identify two of the three strains as C. sakazakii and the last strain was identified as C. malonaticus. Multi locus sequence typing (MLST) analysis was used to identify each strain’s sequence type and the results identified three new sequence types: 303, 304 and 296. C. sakazakii BAA 894 served as a positive control for all the experiments. Biochemical methods and commercial identification systems are not sensitive enough to identify Cronobacter strains to the species level. Molecular methods are needed to confirm the species identity of strains.

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 72% infections 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 78.5% and 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 – 80% and 62.5-97.8% respectively. 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.

We have assessed the prevalence of Escherichia coli O157 in diarrhoeal patients and surface waters from some selected sources in Zaria (Nigeria), evaluating the antibiotic susceptibility and plasmid profiles of 184 E. coli isolates, obtained from 228 water samples and 112 diarrhoeal stool specimens (collected from children aged

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.

(2008). Prevalence of Salmonella typhi among food handlers from bukkas in Nigeria. British Journal of Biomedical Science: Vol. 65, No. 3, pp. 158-160.

Food-borne salmonellosis is the most prevalent disease and major source of Salmonella spp in humans and its detection particularly in developing countries is quite cumbersome and time consuming. Molecular methods for its detection as well as the genotypic diversity of some of the genes responsible for Salmonella virulence are necessary. The aim of the study was to screen for Salmonella spp using the 16S rRNA, to determine whether the invA gene is specific for Salmonella detection as well as virulence genotyping of some genes present in Salmonella spp (invA, sitC and spvA, spvB and spvC) from food samples in Lagos, Nigeria. All 76 isolates tested positive for 16S rRNA gene while 53 (69.7%) were positive for salm3 and salm4 (389 bp) gene. PCR analysis of the invA gene (284bp) showed that 73 (96.1%) were positive, 38 (50%) of the isolates were positive for sitC gene while none were positive for spvA and spvB and with the multiplex –PCR of invA/spvC gene 25 (33%) were positive for invA (244 bp) gene and none positive for spvC gene. The use of invA gene for Salmonella detection in our food samples is recommended however for most of our isolates the virulence genes were not detected.

Background : 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. Study design : 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. Result : 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. Conclusion : 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. Keywords : molecular, methicillin-resistant; Staphylococcus aureus West African Journal of Medicine Vol. 24(2) 2005:100-106

AIM: To comparatively evaluate PCR and other diagnostic methods (the rapid urease test and/or culture) in order to determine which of the three PCR methods (ureA, glmM and 26-kDa, SSA gene) was most appropriate in the diagnosis of Helicobacter pylori (H pylori ) infection and also to evaluate the detection of a putative virulence marker of H pylori, the cagA gene, by PCR in biopsy specimens. METHODS: One hundred and eighty-nine biopsy specimens were collected from 63 patients (three biopsies each) undergoing upper gastroduodenal endoscopy for various dyspeptic symptoms. The PCR methods used to detect H pylori DNA directly from biopsies were the glmM, 26-kDa, ureA and then cagA was used to compare the culture technique and CLO for urease with the culture technique being used as the gold standard. RESULTS: Thirty-five percent of the biopsies were positive for H pylori DNA using the 3 PCR methods, while 68% of these were positive for the cagA gene. Twenty-four percent of the biopsies were negative for H pylori DNA in all PCR methods screened. The remaining 41% were either positive for ureA gene only, glmM only, 26-kDa only, or ureA + glmM, ureA + 26-kDa, glmM + 26-kDa. Out of the 35% positive biopsies, 41% and 82% were positive by culture and CLO respectively, while all negative biopsies were also negative by culture and cagA. Cag A+ infection was also predominantly found in H pylori DNA of the biopsies irrespective of the clinical diagnosis. CONCLUSION: This method is useful for correctly identifying infections caused by H pylori and can be easily applied in our laboratory for diagnostic purposes.

Ocimum gratissimum leaf extracts have been extensively demonstrated to be effective against the various aetiologic agents of diarrhoea, including Shigellae. However, the mechanism of the shigellocidal action of this plant remains to be understood. This study investigated the effects of O. gratissimum essential oil (EO) at subinhibitory concentrations of 0.75 and 1.0 microg/ml on virulence and multidrug-resistant strains of 22 Shigella isolates from Nigeria. Compared with untreated Shigella strains, O. gratissimum EO caused significant decreases (p

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)

Distinct virulence factors of Helicobacter pylori have been associated with clinical outcome of the infection; however, considerable variations have been reported from different geographic regions. Data on genotypes of African H. pylori isolates are sparse. The aim of this study was to determine the prevalence of specific genotypes of H. pylori in Nigerian patients with duodenal ulcer and non-ulcer dyspepsia. H. pylori was cultured from endoscopic biopsies obtained from 41 Nigerian patients (19 with duodenal ulcer, 22 with non-ulcer dyspepsia). The vacA alleles, cagA and iceA genotypes were determined by PCR. The vacA s1,m1 and s1,m2 genotypes were found in 26.3% and 22.7%, and in 73.7% and 72.7% of H. pylori isolates from patients with duodenal ulcer and non-ulcer dyspepsia, respectively. The iceA1 genotype was present in 94.7% and 86.4% of isolates from duodenal ulcer and non-ulcer dyspepsia patients, respectively. cagA + infection was found predominantly (>90%) in Nigerian H. pylori isolates irrespective of the clinical diagnosis. In conclusion, vacA s1,m2, iceA1 and cagA + are common genotypes of H. pylori isolated from Nigerian patients. As in several other developing countries there seems to be no association between these genotypes and duodenal ulcer disease.

Background : Campylobacter jejuni/coli are well established causative agents of diarrhoea. In Nigeria, gastroenteritis due to C. jejuni was first reported in northern part of the country in 1981 and the South-Western part in Ile-Ife in 1983. Objective : To re-examine the role of C. jejuni as an agent of diarrhoea after more than a decade at Ile-Ife, Nigeria and to determine the biological characteristics of local strains. Design : A prospective case control study. Setting : Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC) Ile-Ife, Nigeria. Subjects : Three hundred and three children with diarrhoea and 100 children with other medical conditions other than diarrhoea were randomly selected. Main Outcome Measures : Isolation of C. jejuni/coli from stool samples collected from the patients and controls. Biological characteristics of the isolates. Results : Fifty eight (19.1%) and 6% of the patients and controls, had the organism respectively. Campylobacter coli accounts for 53.3% of isolates. All the isolates were susceptible to erythromycin and there was no evidence of s-lactomase production. Conclusion : Campylobacter jejuni is an important diarrhoea agent in our environment and should be considered strongly in children with diarrhoea. Complete characterization of local, strains is necessary. (East African Medical Journal: 2002 79(8): 423-426)

Campylobacter coli were characterized using sodium dodecyl sulphate-polyacrilamide gel electrophoresis (SDS-PAGE). The isolates were obtained from the faeces of diarrhoeic children with the age range of 0 t 36 months attending paediatric clinic at the Lagos University Teaching Hospital (LUTH) and Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Nigeria. The 16 isolates studied were characterized into seven protein profiles based on their outer membrane proteins (OMPs). The glagella antigens of C. coli had the molecular weights of 24kDa and 84 kDa. The SDS-PAGE proves a reliable and rapid technique for typing strains from sporadic cases. (Af. J. of Clinical and Experimental Microbiology: 2002 3(1): 1-2)

The prevalence of sorbitol-nonfermenting Escherichia coli O157:H7 (EHEC) was assessed in 100 patients with diarrhoea by stool culture on sorbitol MacConkey agar. The cytotoxicity of the EHEC strains was analysed by Vero cell assay and the antimicrobial susceptibility pattern of the isolates was determined. Detection rate of EHEC O157:H7 was 6%. Five of the six patients were males. Three of the isolates were from children and one was from a teenager. All strains induced cytotoxic effects in the Vero cell assay. All isolates were susceptible to most of the antimicrobials tested. The results showed that diarrhoea caused by EHEC O157:H7, a potentially life-threatening pathogen, has remained common particularly among the child population of Lagos during the past 10 years (5). There must therefore be adequate meat and food inspection to improve the general hygiene of local fast food restaurants, so-called 'bukkas', which are regarded as likely sources of infection.

Flagellin gene sequence polymorphisms were used to discrimate amongst 53 strains of Campylobacter jejuni and C. coli. The Campylobacter strains were made up of forty-three strains of Campylobacter jejuni and 10 strains of Campylobacter coli. The results were analysed in relation to Penner serotyping. Twenty DNA PCR -RFLP patterns (genotypes) were identified by analysis of Dde I fragment length polymorphisms in flagellin gene (fla A and fla B) polymerase chain reaction (PCR) products. Flagellin gene 13 genotype was a feature of 15% of strains, followed by flagellin gene 8 (9 %). Differences in fragment patterns were observed not only between members of two species, but also between individual strains of the same species. The strains that were non-typable by the Penner serotype were distributed into 6 flagellin gene types. In conclusion, Dde I fla typing is reproducible and offers high typability. However, when the scheme is used in combination with the Penner serotype it provides improved discrimina­tion for the characterizing and subtyping of isolates.

Forty-three stool samples and rectal swabs were collected from diarrhoeic and 20 non-diarrhoiec patients under 5 years of age at various general hospitals in Lagos. A total of 110 faecal samples from animals (101 from chickens and 9 from pigs) were obtained from Mitchel farm, Agege and Oshodi -Isolo Local Government farms at Ejigbo. Campylobacter species were isolated from 6 (13.9%) of 43 children with gastroenteritis and none from 20 asymptom­atic subjects. Forty-nine (48.5%) isolates from the hundred and one faecal specimen were isolated from chicken, while 3 (33.33%) out of 9 were from pigs. Campylobacter jejuni was the most prevalent accounting for 79% of the total isolates and C. coli accounted for 25% . All the human strains were gentamicin sensitive, while streptomicin and cloxacillin were resistant. Erythromycin had a high activity (83.3%) on human strains and only 59.6% activity on animal strains. About ten percent (9.6%) of the strains produced beta-lactamase.

Diversity based on ribosomal RNA gene-restriction endonuclease digest patterns was detected amongst forty-seven strains of Campylobacter made up of 38 strains of Campylobacter jejuni and 9 strains of Campylobacter coli. Restriction digests of chromosomal DNA prepared by treating with Hae III were probed with an oligonucleotide specific for Campylobacter 16S ribosomal RNA genes. Seventeen distinct hybridization patterns, each indicating the presence of 2 - 4 copies of the 16S rRNA gene are encoded in Campylobacter DNA. Differences in fragment patterns were observed not only between members of two species, but also between individual strains of the same species. Ribopattern fragments of 8.71, 7.56, 2.81 and 1.0 kb were characteristic of the majority of C. jejuni, whereas 7.59 and 4.68 kb fragments were commonly present in C. coli. In conclusion, Hae III ribotyping was even more discriminatory than the Penner serotyping of C. jejuni and C. coli, as strains of the same serotype were distinguished.

Fifty-eight Campylobacter strains were isolated from children with diarrhoea at various health centres in Lagos and from healthy chicken. Twenty -nine strains of Campylobacter were isolated from humans, while the same number were isolated from chicken. The strains were biotyped using the modified Preston biotype scheme. The Preston biotyping results have been compared with the results of Penner serotyping. Out of fifty-eight strains studied, the technique identified ten strains (17%) as C. coli, three (5%) as C. lari and fourty-five (78%) as C. jejuni, by the coding system. This technique identified twenty-eight Campylo­ bacter species. This method highlights the usefulness of this technique in the biotyping of local strains, however, when the two schemes are used in combination they give excellent typing results suitable for epidemiological purposes.