L. O. Egwari

Environmental impact on the bacteriological quality of domestic water supplies in Lagos, Nigeria

OBJECTIVE To assess the impact of town planning, infrastructure, sanitation and rainfall on the bacteriological quality of domestic water supplies. METHODS Water samples obtained from deep and shallow wells, boreholes and public taps were cultured to determine the most probable number of Escherichia coli and total coliform using the multiple tube technique. Presence of enteric pathogens was detected using selective and differential media. Samples were collected during both periods of heavy and low rainfall and from municipalities that are unique with respect to infrastructure planning, town planning and sanitation. RESULTS Contamination of treated and pipe distributed water was related with distance of the collection point from a utility station. Faults in pipelines increased the rate of contamination (p<0.5) and this occurred mostly in densely populated areas with dilapidated infrastructure. Wastewater from drains was the main source of contamination of pipe-borne water. Shallow wells were more contaminated than deep wells and boreholes and contamination was higher during period of heavy rainfall (p<0.05). E. coli and enteric pathogens were isolated from contaminated supplies. CONCLUSIONS Poor town planning, dilapidated infrastructure and indiscriminate siting of wells and boreholes contributed to the low bacteriological quality of domestic water supplies. Rainfall accentuated the impact.

In-vitro studies on the sensitivity pattern of Plasmodium falciparum to antimalarial drugs and local herbal extracts

BackgroundThe resistance of human malaria parasites to anti-malarial compounds has become considerable concern, particularly in view of the shortage of novel classes of anti-malarial drugs. One way to prevent resistance is by using new compounds that are not based on existing synthetic antimicrobial agents.ResultsSensitivity of 100 Plasmodium falciparum isolates to chloroquine, quinine, amodiaquine, mefloquine, sulphadoxine/pyrimethamine, artemisinin, Momordica charantia (‘Ejirin’) Diospyros monbuttensis (‘Egun eja’) and Morinda lucida (‘Oruwo’) was determined using the in vitro microtest (Mark III) technique to determine the IC50 of the drugs. All the isolates tested were sensitive to quinine, mefloquine and artesunate. Fifty-one percent of the isolates were resistant to chloroquine, 13% to amodiaquine and 5% to sulphadoxine/pyrimethamine. Highest resistance to chloroquine (68.9%) was recorded among isolates from Yewa zone while highest resistance to amodiaquine (30%) was observed in Ijebu zone. Highest resistance to sulphadoxine/pyrimethamine was recorded in Yewa and Egba zones, respectively. A positive correlation was observed between the responses to artemisinin and mefloquine (P<0.05), artemisinin and quinine (P<0.05) and quinine and mefloquine (P<0.05). A negative correlation was observed between the responses to chloroquine and mefloquine (P>0.05). Highest anti-plasmodial activity was obtained with the ethanolic extract of D. monbuttensis (IC50 = 3.2nM) while the lowest was obtained from M. lucida (IC50 =25nM).ConclusionsNatural products isolated from plants used in traditional medicine, which have potent anti-plasmodial action in vitro, represent potential sources of new anti-malarial drugs.

Molecular Characterization and Antimicrobial Susceptibility of Staphylococcus aureus Isolates from Clinical Infection and Asymptomatic Carriers in Southwest Nigeria

Few reports from Africa suggest that resistance pattern, virulence factors and genotypes differ between Staphylococcus aureus from nasal carriage and clinical infection. We therefore compared antimicrobial resistance, selected virulence factors and genotypes of S. aureus from nasal carriage and clinical infection in Southwest Nigeria. Non-duplicate S. aureus isolates were obtained from infection (n = 217) and asymptomatic carriers (n = 73) during a cross sectional study in Lagos and Ogun States, Nigeria from 2010–2011. Susceptibility testing was performed using Vitek automated systems. Selected virulence factors were detected by PCR. The population structure was assessed using spa typing. The spa clonal complexes (spa-CC) were deduced using the Based Upon Repeat Pattern algorithm (BURP). Resistance was higher for aminoglycosides in clinical isolates while resistances to quinolones and tetracycline were more prevalent in carrier isolates. The Panton-Valentine leukocidin (PVL) was more frequently detected in isolates from infection compared to carriage (80.2 vs 53.4%; p<0.001, chi2-test). Seven methicillin resistant S. aureus isolates were associated with spa types t002, t008, t064, t194, t8439, t8440 and t8441. The predominant spa types among the methicillin-susceptible S. aureus isolates were t084 (65.5%), t2304 (4.4%) and t8435 (4.1%). spa-CC 084 was predominant among isolates from infection (80.3%, n = 167) and was significantly associated with PVL (OR = 7.1, 95%CI: 3.9–13.2, p<0.001, chi2- test). In conclusion, PVL positive isolates were more frequently detected among isolates from infection compared to carriage and are associated with spa-CC 084.

Antibiotic susceptibility pattern and biofilm formation in coagulase negative staphylococci.

Introduction Coagulase negative staphylococci (CoNS) are commensals of non-sterile sites in humans and become pathogenic mostly when the host is immunocompromised by prior diseases or invasive surgical or related procedures [1]. Slime or biofilm production by CoNS has been identified as an important factor in the pathogenesis of infections as bacteria organized in biofilms are protected from the action of antibiotics and the immune system [2]. Biofilm is ascribed the most important virulence factor of S. epidermidis as it enables attachment and persistence of the bacteria on foreign materials [3,4]. Other studies have indicated a correlation between antibiotic resistance and slime expression. For instance, insertion of a certain transposon influences both biofilm formation and the expression of methicillin resistance in S. epidermidis [4]. In another study methicillin resistance was found to be significantly higher in slime positive isolates (81%) than in slime negative isolates (57%) [5]. Due to the frequent recovery of CoNS in clinical infections their antibiotic susceptibility profile as well as their biofilm forming ability was investigated in this study.

Occurrence of otitis media in children and assessment of treatment options

Background: Otitis media is a more frequent occurrence in children, and the disease may progress from an acute to chronic state if appropriate and timely intervention is not initiated. Methods: A total of 212 children aged 6 months to 10 years were examined and treated for otitis media, in a 13-month hospital-based study. Results: Acute otitis media was diagnosed in 130 (61.3 per cent) of the patients. There were 82 (38.7 per cent) chronic suppurative otitis media cases. The incidence of acute otitis media and chronic suppurative otitis media in the first year of life was 54.6 per cent and 45.1 per cent respectively. Chronic suppurative otitis media patients were assigned to one of three treatment groups. Recovery occurred in 70.4 per cent of amoxicillin-treated patients, in 88.9 per cent of amoxicillin-clavulanic acid treated patients and in 96.4 per cent of culture and antibiotic sensitivity test patients. Relapses were seen only in the amoxicillin (five cases) and amoxicillin-clavulanic acid (two cases) groups. Conclusion: The success rate in patients treated with antibiotics makes this option mandatory for an established diagnosis.

Evaluation of crayfish chaff charcoal agar as a transport medium for anaerobes

O previous studies have shown that deletion of tRNA modification enzyme glucose-inhibited division gene (gidA) significantly attenuated Salmonella enterica serovar Typhimurium (STM) virulence. Transcriptome and proteome analyses indicated that expression of several virulence factors was significantly altered. Most importantly, gidA mutant mice immunized with the gidA mutant were protected against a lethal dose of wild-type (WT) STM. Further studies on the mechanistic basis of this protection indicated both humoral and cellular immunity played a role with the humoral immune response potentially being the main mechanism of protection. GidA together with MnmE thought to catalyze modification of tRNA is required for correct translation during gene expression. Examination of relative contribution of GidA and MnmE in modulation of Salmonella virulence indicated various degree of attenuation and that GidA and MnmE bind together and alters Salmonella tRNA modification. The GidB is a methyltransferase enzyme that is involved in the methylation of the 16S rRNA in bacteria. Deletion of gidB gene indicated a compromised overall bacterial fitness, significantly reduced motility and showed a filamentous morphology under the stress of nalidixic acid. Most importantly, deletion of gidB conferred high-level resistance to the aminoglycoside antibiotics streptomycin and neomycin. This study determined the methylation site for the WT STM to be at G527 of the 16S rRNA. A lack of methylation in the mutant confirmed that GidB is required for this methylation. Taken these data indicated that both GidA and GidB enzymes play a significant role in modulation of biological and virulence characteristics and alteration of antibiotic susceptibility in Salmonella under stress conditions. Amin Fadl, J Microb Biochem Technol 2013, 5:4 http://dx.doi.org/10.4172/1948-5948.S1.009I endocarditis (IE) is a life-threatening disease. Zoonotic bacteria can cause blood culture–negative endocarditis (BCNE). Zoonotic IE is prevalent in North Africa. The study aimed to diagnose IE caused by the zoonotic pathogens Brucella spp., Bartonella spp. and Coxiella burnetii in BCNE by PCR and serology. The study prospectively followed up all patients with suspected IE referred to the Endocarditis Service, Cardiology Department, Cairo University from February 2005 to February 2013. Three sets of blood culture were withdrawn on admission. Resected surgical material was cultured whenever available. Serologic testing was performed for detection of Brucella antibodies using standard agglutination test, IgG titers for Bartonella, and IgG, IgM, and IgA antibody titers for Coxiella burnetii using IFA on the sera of all referred patients. A patient was considered to have endocarditis caused by Brucella when antibody titers exceeded 1/320, Bartonella when IgG titers >1:800, and Coxiella when IgG phase I titer >1:800. Broad range bacterial 16S rRNA from blood culture bottles and surgical materials followed by sequencing for identification of positive cases was done. IE was classified as definite in 300 patients; 50% of them had BCNE. Zoonotic endocarditis was diagnosed as by serology and PCR in 15 (5%) patients including 6cases of Brucella spp., 5 cases of Bartonella spp. and 4cases of Coxiella burnetii. Zoonotic agents were a cause of 9.3% of BCNE. Zoonotic agents are important cause of IE in Egypt.Mycobacterium tuberculosis, acid fast bacilli stained by Ziehl-Neelsen’s technique is a gram-positive bacteria. Infection caused by this organism is an important clinical diagnosis for consideration especially in extra pulmonary location. Despite slow replication rate (15-20 hours), the pathogen survived in many unfavorable conditions due to its unusual acidic wall content; the hallmark for its resistance and virulence. Infection by this organism is often related to the presence of hyper virulence mutant strain. Deletion of modifying enzymes or regulators that respond to environmental stimuli is responsible for these mutants to induce a protective granuloma enabling long-term persistent infection. M.tuberculosis survives and grow in an oxygenated environment to oxidized glucose substrate in order to obtain energy during the process of cellular respiration. Radiopharmaceutical agent 2-deoxy-2( 18 F) fluoro-D-glucose ( 18 F-FDG) is a chemical widely used for in-vivo oncology imaging. This glucose analogue is a positron emitter. When injected into the body, 18 F-FDG is taken into living tissues similar to glucose metabolic pathway. The intensity of uptake depends on the rate of tissue metabolism. This process can be mapped and quantified using a Positron Emission Tomography Computed Tomography system, an integrated imaging modality. This study highlights the features of multisystemic m.tuberculosis infection translated through the rate of tissue metabolism using 18 F-FDG tracer. The presence of m.tuberculosis infection or granulomatous lesion is qualitatively and quantitatively analyzed against microbial isolation and tissue biopsy yield. In view of increasing world wide incidence of m.tuberculosis infection and multidrug resistance (MDR) strain, the encouraging result of this study offer a non-conventional solution in clinical detection of tuberculosis infection granting further studies in translational clinical microbiology using molecular imaging technique.A laboratory formulated crayfish chaff charcoal agar (CCCA) was evaluated both as transport and storage medium for anaerobic bacteria in parallel with Amies charcoal agar (ACA), cooked meat medium (CMM) and thioglycollate broth (TCB). The survival of anaerobes in swab obtained clinical specimens and viability of specific anaerobes in these media were assessed. Eight genera of anaerobes (Bacteroides, Fusobacterium, Parvobacteroides, Porphyromonas, Prevotella, Clostridium, Peptoniphilus, Peptostreptococcus) were isolated from ACA, CMM and CCCA, 7 (Bacteroides, Fusobacterium, Parvobacteroides, Prevotella, Clostridium, Peptoniphilus, Peptostreptococcus) from TCB transported specimens. Comparatively, the difference in isolation rate of anaerobes in aspirate (85%) and swab (75%) processed specimens was not significant (p < 0.05). Irrespective of storage temperature (-20°C or 30 + 2°C), positive anaerobic cultures from 7-day stored swab specimens in transport media were TCB 10, CCCA 14, ACA and CMM 18 each. Anaerobes recovery from CCCA and ACA were comparable (p < 0.05). Quantitatively, Bacteroides was recovered after 6 weeks of storage in CCCA with counts of 10 6.1 and 10 5.6 CFU/ml at -20°C and 30 + 2°C respectively. Similar pattern of recovery occurred with Prevotella, Clostridium and Peptoniphilus in CCCA, ACA and other transport media with no significant differences in viable counts (p < 0.05). The CCCA function is comparable with those of the other media and can be prepared and used in-house for transport of clinical specimens and short term storage of anaerobes.Background Respiratory tract infection is leading causes of death among HIV infected patients in Vietnam. Identification the agents caused RTIs is very important to give specific treatments leads to reduce mortality rate among HIV/AIDS patients suffering from RTIs. Methods We conducted a prospective cross-sectional study of 170 HIV/AIDS patients with clinical manifestations of respiratory tract and/or broncho aveolar lesions through chest X-ray films to indentify the common agents by analyzing bronchoaveolarlavage (BAL). Results A total of 170 HIV/AIDS patients (138 male and 32 female) were involved in the study and 170 BAL samples had been taken for AFB, cultures and PCR. 148/170 (87.1%) patients had been diagnosed RTIs with following agents: Mycobacterium tuberculosis 79/148 (53.4%), PJP 12/148 (8.1%), bacteria 59/148 (39.9%), fungi 54/148 (36.5%) and CMV 2/148 (1.4%). 52/148 (35.1%) patients had been isolated 2 differential agents at a moment: the common concurrent infections are MTB-Fungi (16 patients), MTB-Bacteria (14 patients) and Bacteria-Fungi (11patients). . Most patients have very low CD4+ count (80.4% ≤ 100cells/mm3; mean = 74.6; SD = 118.7; median = 22). The most common bacteria are: Pseudomonas (P.aeruginosa, P.putida, P.pneumotropica) 15/59 (25.4%), Streptococcus (S.pneumoniae, S.pyogene) 11/59 (18.6%), Acinobacter (Aci.baumani, Aci.juni, Aci.minimus) 6/59 (10.2%), E.coli 3/59 (5.1%) and S.aureus 3/59 (5.1%). Other included: H.influenza 2/59 and each following spp have 1: Achromobacter xylosoxidans, K.pneumoniae, Enterobacter clocae, Moraxella catarhalis, and Rhodococcus equi. Isolated fungal spp include: Candida albicans 32/54 (59.2%), Penicillium marneffei 14/54 (25.9%), Aspergilus spp 4 (7.4%), Candida spp 3/54 (5.6%) and Cryptococcus neoformans 1/54 (1.9%). Conclusion Mycobacterium tuberculosis, bacteria (P.aeruginosa, P.putida, P.pneumotropica, S.pneumoniae, S.pyogene, and Aci.baumani) and fungi (Candida albicans and Penicillium marneffei) are the common agents caused RTIs in HIV/AIDS patients. Because of advanced immune depression, patients may have concurrent infections in a moment.B rapidly respond and adapt to changing environmental conditions by altering gene expression. A gram-negative opportunistic bacterium, Pseudomonas aeruginosa is a major human pathogen implicated in a number of acute and chronic infections. Of particular concern is the wide prevalence of antibiotic resistant P. aeruginosa in hospitals. Expression of virulence factors that contribute to P. aeruginosa pathogenicity is tightly regulated. Regulators make up ~8-10% of the P. aeruginosa genome. A transcriptional regulator of the LysR family, AmpR plays a major role in conferring resistance to s-lactams by positively regulating ampC encoding a lactamase. Whole genome approaches such as microarrays, deep RNA sequencing, CHIP-Seq and proteomics analyses of the P. aeruginosa prototypic strain PAO1 and its isogenic ampR in-frame deletion mutant, PAO∆ampR, in the absence and presence of s-lactams, revealed that the regulatory repertoire of AmpR is extensive and includes over 500 genes. AmpR regulates diverse phenotypes such as s-lactam and non-s-lactam resistance, many virulence processes and metabolism. AmpR regulated positively and negatively, phenotypes associated with acute and chronic infections, respectively. Furthermore, RNA-Seq and ChIP-Seq studies identified lasR, encoding the quorum-sensing regulator, to be a direct target of AmpR regulation. In silico comparative transcriptomics analyses further identified genes that are exclusively regulated by AmpR and core set are involved in bacterial homeostasis. In summary, AmpR is identified as a critical regulator of pathogenesis and metabolism in P. aeruginosa and is a potential therapeutic target. Kalai Mathee, J Microb Biochem Technol 2013, 5:4 http://dx.doi.org/10.4172/1948-5948.S1.009

Characterization of Panton–Valentine leukocidin-positive Staphylococcus aureus from skin and soft tissue infections and wounds in Nigeria: a cross-sectional study

Background: Staphylococcus aureus is a significant pathogen implicated in numerous nosocomial and community-acquired infections. The Panton–Valentine leukocidin (PVL) can be associated with severe necrotizing diseases such as pneumonia, skin and soft tissue infection (SSTI). Methods: In total, 96 S. aureus isolates were obtained from patients presenting with wounds (n=48) and soft tissue infections (SSTIs, n=48). These were characterized based on their antimicrobial susceptibility profile, the possession of virulence genes (e.g. capsular type, PVL), accessory gene regulator ( agr) type, and the staphylococcal protein A ( spa) type. The production of the PVL protein was assessed by western blotting. Results: All isolates were susceptible to methicillin. The resistance was highest to penicillin (97.9%), followed by trimethoprim/sulfamethoxazole (85.4%) and tetracycline (10.4%). The PVL gene was found in 83.3% of isolates from SSTIs and in 79.2% of isolates from wound. Of these, 53 (68%) produced PVL as assessed by western blotting. The most prevalent spa type was the t084 (78.1%, n=75) and, majority of the isolates carried agr2 (82.3%, n=79). Conclusions: Prevalence of antibiotic resistant PVL-positive methicillin susceptible S. aureus strains has severe implications on PVL mediated infections.

Data set on Rapid Diagnostic Tests (RDTs) and Microscopy for Diagnosing Plasmodium falciparum And Plasmodium vivax

The World Heal Organization (WHO) has identified malaria diagnosis as being pivotal to eradicating the disease by 2030 as stipulated in the Sustainable Development Goals (SDG). The data presented here was obtained from outpatients of a hospital in the South Western Region of Nigeria from November 2016 to May 2017. The data contains malaria incidence amongst asymptomatic and symptomatic outpatients in the period under review. Malaria incidence was obtained using two diagnostic test kits, Bioline SD (HRP-2) and ACON (HRP-2/Aldolase) alongside Microscopy as gold standard. Specificity, Sensitivity and Kappa statistic of each test device is presented in the tables herewith. Data presented here could be used alongside other data sources to assess the state of malaria diagnostics.

Dataset on the knowledge, attitudes and practices of university students towards antibiotics

Antibiotic resistance is a major public health issue globally fuelled largely by its misuse. Controlling this problem would require an understanding of the levels of awareness of the population towards antibiotics. The data presented here was obtained from undergraduate students attending a Nigerian University in the first three months of the year 2016. The data is stratified by such demographic variables as age, sex and level of study. It contains information about the knowledge, and predispositions of participants to antibiotics and antibiotic resistance. Preliminary descriptive statistics are presented in the tables and figures herewith. Data was analysed using SPSS-20 and is available for reuse in the native SPSS format. In concluding, this data can be used to model the determinants of antibiotic knowledge among students.

In vivo Antiplasmodial Activity of Crude Ethanolic and N-hexane Extracts of Moringa oleifera Leaves

This study was carried out to determine the antiplasmodial activity of leaves of Moringa oleifera. Cold extraction method was carried out on grindedleaves to prepare the crude ethanolic and n-hexane extracts. Mice models (Mus musculus) were passaged with chloroquine resistant Plasmodium berghei,which are similar in morphology, physiology and life cycle to P. falciparumthat infect humans. Stock solutions of 5mg/mL5% DMSO were prepared and the extracts wereadministered atdifferent treatment concentrations, 50mg/kg, 100mg/kgand 200mg/kg body weight over 4days. Positive and negative control groups, Chloroquine diphosphate (25mg/kg) and 5% DMSO,respectively were set up. Crude ethanolic and n-hexane extracts of M. oleiferashowed anti-plasmodial activity at the three different concentrations used. Both crude ethanolic and n-hexane extracts of M. oleiferaleaves showed a significant inhibition of parasitaemia (p < 0.05) ranging from 74.7 to 95.6% for ethanolic extract and 59.3 to 87.9% for n-hexane extract. EC50value of crude ethanolic and n-hexane extractswere 32mg/kg and 42mg/kg body weight,respectively. M.oleifera showed potential for possible future use as an alternative to some conventional drugs.© 2016 Friends Science Publishers