Detection of tem-1 and class-1 integrons in multidrug resistant uropathogens from HIV patients with asymptomatic bacteriuria in a Tertiary Care Hospital, SouthWest Nigeria.

Background: Human immunodeficiency virus (HIV) infected individuals are at increased risk of asymptomatic bacteriuria (ASB) due to immune suppression. The increasing resistance of uropathogens necessitates the need for regular monitoring of their profile to reduce drug resistance. Objectives: We determined the prevalence of ASB and the characteristics of antibiotic-resistant uropathogens isolated from HIV patients. Methods: Mid-stream urine samples from 100 HIV positive and 100 HIV negative healthy individuals were cultured for significant bacteriuria. The isolates were identified by standard techniques and their susceptibility patterns determined by the Kirby-Bauer disc diffusion technique. All the Gram-negative isolates were screened for ESBL production by combined disc method, ESBL genes and class 1 integrons by Polymerase chain reaction. Results: Nine (9%) HIV positive individuals and 4 (4%) healthy individuals had ASB yielding a total of 13 (6.5%) uropathogens dominated by Escherichia coli (53.9%). All isolates were multidrug resistant. Five isolates harboured both the blaTEM-1 gene and class 1integrons while Serratia liquefaciens produced ampC. Conclusion: There is a higher burden of ASB characterized by multi-drug resistant uropathogens among HIV patients. Thus emphasizing the need for continuous resistance surveillance and antibiotic stewardship in our environment to reduce drug resistance and prevent treatment failure.

Prevalence, diversity of diarrhoeagenic Escherichia coli and associated risk factors in well water in Ile-Ife, Southwestern Nigeria.

BACKGROUND: Diarrhoeagenic Escherichia coli (DEC) strains are common causes of morbidity and mortality worldwide. Waterborne DEC could pose a health risk to humans through domestic use of contaminated water. However, epidemiological studies on DEC in well water are scarce in Nigeria. This study determined the prevalence, diversity and factors associated with the presence of DEC in well water in Ile-Ife, southwestern Nigeria. METHODS: We assessed 143 wells for safety and a questionnaire was administered. Contaminating isolates were identified as E. coli by amplifying their 16S rRNA gene. Five diarrhoeagenic E. coli pathotypes were sought using multiplex polymerase chain reaction (PCR). (GTG)5 repetitive PCR and Shannon diversity index were used to determine isolates diversity. Multivariate analysis was used to reveal the factors associated with the presence of DEC in  well water. RESULTS: Fifty-six (39.2%) wells were contaminated by diarrhoeagenic E. coli. Wells with dirty platforms, undercut by erosion and sited near septic tanks significantly harboured DEC (p <  0.05). There was a preponderance of Shiga-toxin producing E. coli among the isolates with 10 (17.9%) wells contaminated by multiple DEC. The DEC isolates showed 45 unique fingerprints and were divided into six clades, with an overall diversity index of 18.87. DISCUSSION: The presence of DEC in well water highlights the risk to human health associated with the use of untreated water. There was a high degree of genetic diversity among the isolates implying multiple sources of contamination. There is a need for periodic sanitation and inspection of wells for cracks to prevent seepages and possible outbreaks of waterborne diseases.

NASAL CARRIAGE OF MULTI-DRUG RESISTANT PANTON VALENTINE LEUKOCIDIN POSITIVE STAPHYLOCOCCUS AUREUS IN HEALTHY INDIVIDUALS OF TUDUN-WADA, GOMBE STATE, NIGERIA.

BACKGROUND: Panton-Valentine Leucocidin (PVL)-producing Staphylococcus aureus strains have been implicated in serious community-associated invasive infections and their increasing multidrug resistance is a major global health concern. Thus, we investigated the prevalence of the PVL gene and the antimicrobial resistance profile of nasal S. aureus isolates from healthy adults in Tundu-Wada, Gombe State of Nigeria. METHODS AND MATERIALS: A total of 262 nasal samples from healthy adults were obtained and cultured. The isolates were identified as S. aureus by standard morphological and biochemical methods alongside with the Polymerase Chain Reaction (PCR) amplification of their 16S rRNA gene. Antimicrobial susceptibility testing was performed by the disc diffusion technique and the presence of mecA and PVL genes was determined by PCR analysis. RESULTS: The overall nasal colonization of S. aureus was 17.6%. The prevalence of haemolysin and biofilm production among the isolates was 25(54.3%) and 42(91.3%), respectively. Only 2(4.3%) and 5(10.9%) possessed mecA and PVL genes respectively but none of the isolates harboured these two genes. All the isolates were resistant to amoxicillin but were highly susceptible (93.7%) to gentamicin. The prevalence of multi-drug resistance (MDR) among the isolates was M 45.7% and all PVL-producing isolates were MDR while one of the isolates with mecA gene exhibited extensive-drug resistance (XDR). CONCLUSION: This is the first report of nasal colonization of MDR PVL-producing S. aureus in healthy adults in Gombe, Northeastern Nigeria. This study highlights the importance of routine surveillance of healthy populations to provide useful strategies for controlling the spread of virulent multidrug-resistant organisms within the community.

Phenotypic and molecular characterization of antimicrobial resistant Escherichia coli from urinary tract infections in Port-Harcourt, Nigeria.

INTRODUCTION: Multidrug resistance among Escherichia coli causing Urinary Tract Infections (UTIs) is a major public health problem, threatening the effective treatment of UTIs. This study investigated the phenotypic and molecular characteristics of E. coli associated with UTIs in Port-Harcourt, Nigeria. METHODS: Twenty-five non-duplicate isolates of E. coli from UTIs patients at the University of Port-Harcourt Teaching Hospital, Nigeria were identified using Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry. The antimicrobial susceptibility patterns were determined using Kirby-Bauer disc diffusion technique. Phenotypic expression of Extended Spectrum Beta Lactamases (ESBLs) and AmpC beta-lactamase were determined using standard laboratory methods and polymerase chain reaction (PCR) was used to detect ESBLs, AmpC, Quinolones and Aminoglycosides resistance genes. RESULTS: The isolates exhibited high rates of resistance to co-trimoxazole (76%), nalidixic acid (68%), ciprofloxacin (60%), gentamicin (44%) and low resistance to cefotaxime (20%) but were fully susceptible to cefoperazone/sulbactam, amikacin, nitrofurantoin, colistin and carbapenems. Phenotypic expression of ESBLs was recorded in 6(24%) isolates while genotypic detection revealed the highest prevalence of blaTEM 22(88%), followed by blaCTX-M-15 16(64%), blaSHV 7(28%) and blaOXA-1 6(24%) while AmpC (blaCMY-2) gene was detected in 8(32%) isolates. Amongst the quinolone resistant isolates, qnr variants (qnrB, qnrD and qnrS) and aac(6')-Ib genes were detected in 7(28%) and 3(12%) isolates respectively while all gentamicin resistant isolates possessed the aacC2 gene. The co-expression of blaCTX-M-15 with quinolones and aminoglycoside genes were 20% and 40% respectively. The prevalence of multiple drug resistance was 52%. CONCLUSION: A high proportion of the studied E. coli isolates co-expressed ESBLs, quinolones and aminoglycosides resistance genes which call for prompt antibiotic stewardship and preventive strategies to limit the spread of these genes.

CARRIAGE OF MULTI-DRUG RESISTANT UROBACTERIA BY ASYMPTOMATIC PREGNANT WOMEN IN YENAGOA, BAYELSA STATE, NIGERIA.

BACKGROUND: Urinary Tract Infections (UTIs) in pregnancy are associated with significant morbidity for both mother and baby but its early detection and treatments can prevent unfavorable complications in pregnancy. This study therefore determined the prevalence of asymptomatic bacteriuria and antimicrobial resistance profile of the urinary bacteria among pregnant women in Yenagoa, Bayelsa State, Nigeria. MATERIALS AND METHODS: Mid-stream urine samples were collected from 201 apparently healthy pregnant women attending antenatal clinics in Yenagoa. The samples were analyzed and the organisms identified using standard microbiological methods. Haemolysin production by the organisms was screened and their antimicrobial susceptibility was performed using standard assay methods. RESULTS: A high significant bacteriuria of 119 (59.2%) was predominantly recovered from the pregnant women in their second and third trimesters. The bacteria isolated; Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus species had 36 - 67% of haemolysin producers. The bacteria exhibited a very high resistance to most of the antibiotics tested but the resistance to ceftazidime, gentamicin and ciprofloxacin was 28 - 67%. All the Staphylococcus species exhibited 90% and 85% resistance to cefoxitin (methicillin resistant) and vancomycin respectively. An 89 - 100% of the bacteria exhibited multiple antibiotic resistance and 72.3% of the screened bacteria phenotypically expressed Extended-Spectrum Beta-lactamase production. CONCLUSION: The high prevalence of significant bacteriuria with high multi-drug resistance among the study pregnant women call for regular education on proper personal hygiene and the need for early screening for UTIs during antenatal clinics as means of controlling the spread of antibiotic resistant organisms and complications in pregnancy.

Virulence and antimicrobial resistance of common urinary bacteria from asymptomatic students of Niger Delta University, Amassoma, Bayelsa State, Nigeria.

BACKGROUND: Asymptomatic bacteriuria frequently occurs among all ages with the possibility of developing into urinary tract infections, and the antimicrobial resistance patterns of the etiologic organisms are essential for appropriate therapy. Thus, we investigated the virulence and antimicrobial resistance patterns of common urinary bacteria in asymptomatic students of Niger Delta University, Amassoma, Bayelsa State, Nigeria in a cross-sectional study. MATERIALS AND METHODS: Clean catch mid-stream early morning urine samples collected from 200 asymptomatic University students of aged ranges 15-30 years were cultured, screened and common bacteria were identified using standard microbiological procedures. The isolates were screened for hemolysin production and their susceptibility to antibiotics was determined using standard disc assay method. RESULTS: A total prevalence rate of 52.0% significant bacteriuria was detected and it was significantly higher among the female with a weak association (χ (2) = 6.01, phi = 0.173, P = 0.014). The Klebsiella pneumoniae and Staphylococcus aureus isolates were most frequently encountered among the isolated bacteria and 18 (12.7%) of all the bacterial isolates produced hemolysins. All the bacterial isolates exhibited 50-100% resistance to the tested beta-lactam antibiotics, tetracycline and co-trimoxazole. The isolated bacteria were 85-100% multi-drug resistant. However, most of the isolates were generally susceptible to gentamicin and ofloxacin. The phenotypic detection of extended-spectrum beta-lactamases was 9 (9.6%) among the tested Gram-negative bacterial isolates. CONCLUSIONS: The observed high proportions of multidrug resistant urinary bacteria among asymptomatic University students call for the need of greater control of antibiotic use in this study area.

A study of the prevalence of diarrhoeagenic Escherichia coli in children from Gwagwalada, Federal Capital Territory, Nigeria.

INTRODUCTION: Diarrhoeagenic Escherichia coli (DEC) are major causes of diarrhoea in Nigeria. This study was conducted to determine the prevalence of diarrhoea caused by DEC within the Federal Capital Territory, Abuja, Nigeria. METHODS: A total of 730 rectal swabs obtained from 201 children with diarrhoea and 529 healthy controls aged 0-24 months were cultured for the isolation of Escherichia coli. All E. coli isolates were investigated by PCR to determine their pathotype. RESULTS: A total of 61 DEC strains were recovered at a rate of 18.4% and 2.6% from children with diarrhoea and healthy controls respectively. The DEC strains recovered were Enteroaggregative Escherichia coli (34.4%), Shiga-toxin producing Escherichia coli (31.1%), Enterotoxigenic Escherichia coli(18.0%), typical enteropathogenic Escherichia coli (15.0%) and Enteroinvasive Escherichia coli (1.6%). Shiga-toxin producing Escherichia coli andEnteroinvasive Escherichia coli were recovered only from children suffering from diarrhoea and the overall prevalence of DEC strains was significantly higher among the children with diarrhoea (P < 0.0001). The number of DEC strains obtained during the dry season was significantly higher (P = 0.012) than the number obtained in the rainy season. CONCLUSION: Diarrhoea caused by E. coli in the Nigerian children studied is associated with several diarrhoeagenic pathotypes and a significant proportion of the healthy children were found to harbour EAEC and ETEC strains. These asymptomatic carriers may be regarded as potential transmitters of infection to vulnerable children in the study area.

Antimicrobial resistance of Staphylococcus aureus strains from patients with urinary tract infections in Yenagoa, Nigeria.

CONTEXT: Antimicrobial resistance in Staphylococcus aureus infections is a global public health problem resulting in very limited treatment options. This study determined the antimicrobial resistance pattern of S. aureus strains from urinary tract infections (UTIs) to commonly used antimicrobial agents. MATERIALS AND METHODS: Midstream urine specimens of UTIs symptomatic patients from public and private health institutions in Yenagoa, Nigeria were collected, cultured, and screened for common pathogens using standard microbiological protocols. The antimicrobial susceptibility of identified S. aureus strains was evaluated using disc diffusion and agar dilution techniques. RESULTS: A total of 46 (33.6%) S. aureus strains were identified from 137 growths of the 200 urine specimens. All the S. aureus isolates were methicillin resistant; they exhibited total resistance to ampicillin, 97.8% to tetracycline, 80.4% to chloramphenicol and co-trimoxazole, 73.9% to gentamicin, 69.6% to augmentin and vancomycin, 54.3% to cefuroxime, 39.1% to nitrofurantoin, 34.8% to ofloxacin, and 32.6% to ciprofloxacin. The isolates were commonly resistant to 7 (77.8%) of the nine classes of antimicrobial agents used in this study and 45 (97.8%) of all the isolates were multi-resistant. CONCLUSION: The faster rate at which this pathogen is developing resistance to nitrofurantoin and fluoroquinolones is reducing their usefulness in the empiric treatment of uncomplicated UTIs. Thus, the need to adopt new strategies in the control of antibiotic resistance in this country cannot be overemphasized.

Multidrug-resistant intestinal Staphylococcus aureus among self-medicated healthy adults in Amassoma, South-South, Nigeria.

Multiple antibiotic resistant Staphylococcus aureus is one of the common causes of severe nosocomial infections, and the gastrointestinal tract is an important source of its transmission. This study assessed the previous usage of antibiotics by healthy adults (university students and villagers) in Amassoma, Nigeria, and investigated the antimicrobial resistance patterns of their intestinal S. aureus isolates. A questionnaire was used for evaluating the previous usage of antibiotics by the volunteers. Stool samples were collected and cultured, and S. aureus isolates were confirmed using standard microbiological protocols. Their antimicrobial resistance patterns were determined using disc-diffusion and agar dilution techniques. In total, 54 (45.0%) volunteers used antibiotics on self-medications, and the practice was significantly higher (p=0.01) among the villagers than among the students. The level of judicious use of prescribed antibiotics was significantly higher (p=0.003) among the students than among the villagers. Thirty-eight (31.7%) healthy adults were colonized with intestinal S. aureus. The percentages of resistance of the isolates to some antibiotics were as follows: ampicillin-68.4%, doxycycline-60.5%, cefoxitin-34.2%, vancomycin-36.8%, erythromycin-34.2%, and gentamicin-5.3%. Twenty-five (65.8%) of the isolates were multidrug-resistant. The need for sound education on the appropriate use of antibiotics and the importance of proper personal hygiene as means of controlling the spread of bacterial antibiotic resistance are highlighted. Thus, effective strategies in these areas are strongly recommended.

Preliminary phytochemical screening and antimicrobial evaluation of three medicinal plants used in Nigeria.

Methanol extract of three Nigerian medicinal plants were screened for antimicrobial activity using modified Kirby-Bauer disc diffusion and agar dilution techniques to determine the diameters of zone of inhibition and minimum inhibitory concentrations (MIC) of the extracts respectively. The extract of each of the plants were tested against five clinical bacterial isolates comprising of two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia) organisms. All the extracts exhibited moderate to high level of antimicrobial activities against these microorganisms. Phytochemical screening of powdered plant material revealed the presence of some secondary metabolites such as alkaloids, saponins, tannins, anthraquinones and flavonoids. These Nigerian medicinal plants could be developed into cheap, safe and culturally acceptable standardized herbal products and may serve as a source of new molecules for broad-spectrum antimicrobial agents.