Browsing by Author "Mbanga, Joshua"

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    Antibiotic Resistance Patterns and Virulence Factors of Coagulase Negative Staphylococcus Associated with Urinary Tract Infections in Bulawayo Province, Zimbabwe
    (SCIENCEDOMAIN international, 2016) Mbanga, Joshua; Masuku, Sithabile; Luphahla, Silence
    Aims: To determine the antibiotic resistance patterns and virulence factors of coagulase negative Staphylococcus (CoNS) associated with urinary tract infections (UTIs). The virulence factors assayed for were the atl E and ica AB genes. The prevalence of the antibiotic resistance gene, mec A, was also determined. Place and Duration of Study: Southern Pathology Clinical Laboratories and the National University of Science and Technology microbiology department, between December 2012 and March 2015. Methods: A total of 754 urine samples were analyzed for bacteria by standard procedures. Fromthese, 126 isolates were positively identified as CoNS. Antimicrobial susceptibility testing of the isolated CoNS was done using the disc diffusion method.The polymerase chain reaction (PCR) was also carried out to detect the presence of the mec A, ica AB and atl E genes. Results: Antibiogram profiles showed that CoNS had high prevalences of resistance to nalidixic acid (88.1%), cotrimoxazole (72.2%) and oxacillin (69.8%).There were however high prevalences of sensitivity to nitrofurantoin (79.4%) and gentamycin (68.3%). A total of 106 (84%) isolates were resistant to three or more antibiotics and 12 multi-drug resistance patterns were observed. The most common pattern (resistance to nalidixic acid, ampicillin, oxacillin, tetracycline and cotrimoxazole) was exhibited by 33 isolates. A total of 40 CoNS isolates were then used to determine the prevalence of the mec A, ica AB and atl E genes. PCR results showed that most isolates 25/40 (62.5%) were positive for the mec A gene. The ica AB and atl E were detected in 32.5% and 25% of the isolates respectively. All isolates which were positive for both the mec A and ica AB genes showed resistance to multiple antibiotics. Conclusion: There is emerging antibiotic resistance in CoNS that cause UTI’s. The occurrence of both the mec A and ica AB genes in CoNS isolates may lead to an increase in antibiotic resistance
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    Antimicrobial resistance of Escherichia coli isolated from chickens with Colibacillosis in and around Harare, Zimbabwe.
    (American Association of Avian Pathologists, 2012-11-14) Saidi, Bamusi; Mafirakureva, Prettimore; Mbanga, Joshua
    Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC),can lead to great economic losses in the poultry industry. The aim of this study was to determine the prevalance of antibiotic resistance and antibiotic resistance and antibiotic resistance patterns in APEC in Zimbabwe. From 503 chickens diagnosed with Colibacillosis, 103 E. coli isolates were obtained. Isolation and identification of E. coli were carried out using microscopy and boichemical tests. The disc diffusion method was used to determine antibiotic susceptibility of the isolates to 8 commercial antibiotics. Many isolates exhibited resistance to more than one antibiotic. Antibiogram profiles indicated maximum resistance to tetracycline (100%), bacitracin(100%), and cloxacillin (100%) and a high prevalence of resistance to ampicillin(94.1%0. However; there were high prevalences of sensitivity to ciprofloxacin (100%) and gentamycin (97.1%). The isolates showed moderate rates of sensitivity to chloramphenicol and neomycin.All isolatesin this study showed multidrug resistance because they were all resistant to 3 or more antibiotics. Seven multidrug resistance patterns were observed. The most common pattern (resistance to ampicillin, bacitracin,cloxacillin and tetracycline) was exhibited by 30 isolates.Our findings show that there is emerging drug resistance in APEC associated with colibacillosis in Zimbabwe. The observed high level of multidrug resistance could hamper the treatment of colibacillosis in Zimbabwe.
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    Characterization of Fasciola gigantica isolates from cattle from South-western Zimbabwe using RAPD-PCR
    (International Organization Of Scientific Research (IOSR)., 2014) Chauke, E.; Dhlamini, Zephaniah; Mbanga, Joshua; Dube, S.
    The study sought to characterize Fasciola gigantica isolates from cattle in different localities using RAPD-PCR. Adult flukes morphologically identified as F. gigantica were collected from slaughtered infected animals during meat hygiene inspections. DNA was extracted from single flukes and subjected to RAPD-PCR analysis. In the RAPD-PCR analysis, genomic DNA isolated from the conical anterior end of the worms was amplified by the polymerase chain reaction using 10 random oligonucleotide primers. Depending upon the Fasciola gigantica isolate-primer combination, 1-13 DNA fragments in the range of 75-2000bp were amplified. It was observed that all the 10 primers directing amplification of DNA were of potential interest in the generation of polymorphic DNA. The percentage polymorphic loci ranged from 33.33-100%. Polymorphic bands were scored and used to calculate Nei’s 1978 genetic distance. The genetic distance values ranged between 0.0690 (isolate 5 and 6 from Gwanda and 0.6109 (isolate 6 from Gwanda and isolate 14 from Matopo). The mean Nei’s gene diversity was 0.2839. The study showed the variability of Fasciola gigantica isolates from the same host, using RAPD markers could be applied as a low cost way of identification
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    Effect of Method of Inoculation, Moisture and Seedling Age on Foliar Anthracnose Development in Two Varieties of Sorghum bicolar (Kadoma 332 and Marapansi)
    (Academy Science Journals, 2010-10-26) Dube, S.; Chifamba, Olive; Mbanga, Joshua
    The infection efficiency of Colletotrichum sublineolum was determined on two Sorghum bicolar varieties Kadoma 332 and Marapansi. In all situations Marapansi was resistant to Colletotrichum sublineolum whereas K332 was susceptible to varying degrees in different situations. Pathological development progressed as follows; a few circular spots appeared after inoculation and their number increased progressively. Initially they developed into circular well defined elliptical lesions ranging from tan to brown in colour with straw coloured centers which were spotted with minute black specks. Extensive areas of dry tissue were observed leading to the death of mainly the basal leaves as the infected areas coalesced. Bagging showed improvement for the onset and development of the disease with the application of conidial spores being more effective for disease onset than infected leaf powder for both bagged and none bagged plants. Effect of the age of the plant on susceptibility was investigated. This involved inoculation of the plants at three different growth stages. These were the seedling stage, growth stage 3 and growth stage 5 (the booting stage). Development of anthracnose in K332 was optimized at Stage 5 followed by stage 3 then stage one. Increasing the frequency of bagging above once every other day did not improve chances of onset and development of anthracnose on the tested plants. In vitro experiments to study the mode of entry and proliferation of the fungus and its optimal temperature of growth revealed that spores germinated within 24 hours and 27 o C was found to be the optimal temperature for fungal development.
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    An evaluation of the antimicrobial activities of aloe barbadensis:A. chabaudii and A. arborescens leaf extracts used in folklore veterinary medicine in Zimbabwe
    (2010) Mbanga, Joshua; Mangoma, Ngonidzashe; Saidi, Bamusi
    The antimicrobial activities of Aloe barbadensis Miller(Aloe vera), A. chabaudii and A. Arborescens sap extracts on selected microorganisms were determined. Methanol as well as aqueous extracts of these plants were obtained and then tested for their antimicrobial activities using the disc diffusion assay. The extracts were assayed againstgram positive bacteria (Staphylococcus aureus, Bacillus substilis), gram negative bacteria (Escherichia coli, Salmonella typhimurium, S. gallinarum, Klebsiellasp., Proteussp.) and Candida albicans. The study showed that the sap extracts of the three Aloes had antimicrobial activity against all the tested microorganisms. The antimicrobial activity of the methanol extracts were significantly higher than those of the aqueous (warm and cold) extracts (one tailed t-test, p<0.05). There was no significant difference in the antimicrobial activities of the aqueous extracts (one tailed t-test, p<0.05). S. typhimurium and S. gallinarum were the least susceptible to the extracts tested E. coli, Proteussp., Klebsiellasp. and C. albicans were the most sensitive.
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    Evolution of antimicrobial resistance of Salmonella enteritidis (1972–2005)
    (AOSIS OpenJournals, 2014-11-12) Khumalo, Jermaine; Saidi, Bamusi; Mbanga, Joshua
    With the extensive use of antibiotics in livestock production, surveillance revealed an increase in salmonella resistance to the commonly used antimicrobials in veterinary and public health. This serious threat to health care is further exacerbated by the limited epidemiological information about the common zoonotic agent, Salmonella enteritidis, required to determine antibiotic therapy. The aim was to characterise the antimicrobial resistance patterns of S. enteritidis isolates across different timelines (1972–2005) with accompanying genetic changes being investigated. Thirty-seven stored S. enteritidis isolates were collected from the Central Veterinary Laboratory, Harare, with antimicrobial susceptibility determined against eight antibiotics. Plasmids were isolated to analyse any genetic variation. An overall significant increase in resistance (p < 0.05) to nalidixic acid (0% – 10%), ampicillin (14.3% –50%), tetracycline (14.3% – 30%) and erythromycin (71.4% – 100%) was observed across the timeline. However, the highest rates of susceptibility were maintained for gentamicin, sulphamethoxazole-trimethoprim, kanamycin and chloramphenicol. We report an increase in multidrug resistance (MDR) of 14.2% – 50% with an increase in resistotypes and plasmid profiles across the timeline. Eleven plasmid profiles were obtained in the 37 isolates studied with a minority of isolates (21.6%, 8/37) harbouring a 54 kb plasmid, commonly serovarspecific. A concerning increase in antimicrobial resistance to commonly administered drugs was observed across the timeline. The surge in MDR is of great concern and implies the need for consistent antimicrobial stewardship. No correlation was observed between the plasmid and antibiotic profiles.
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    Identification of Foot and Mouth Disease Virus Isolates Using Vp1 Gene Sequencing
    (Zimbabwe Journal of Science & Technology, 2017) Dyirakumunda, Brighton; Saidi, Bamusi; Mbanga, Joshua
    Foot-and-mouth disease (FMD) is a severely infectious and economically devastating viral disease worldwide, which affects domestic animals with cloven hooves (artiodactyls) and more than 70 species of wild animals. The virus is highly variable with 7 serotypes and numerous subtypes. VP1 is the main immunogenic viral protein of FMDV and using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and nucleotide sequencing, it can be used to characterize type, subtype and determine genetic distances among circulating FMD viruses. The aim of the study was to use VP1 gene sequencing to identify FMDV isolates obtained from the Central Veterinary Laboratory, Harare, Zimbabwe. A total of 35 probang samples were collected from the virology section at CVL. The samples consisted of stored probangs collected from FMDV infected cattle in 2014 and 2015. The VP1 gene was successfully amplified by RT-PCR in16 samples. Only 9 samples that had strong PCR bands were sequenced and used to identify FMD viruses using similarity based annotation approaches. Out of the 9 PCR products sequenced, 7 VP1 sequences were submitted to GenBank and assigned the following accession numbers: KT879751, KT879752, KT879753, KT879754, KT879755, KT879756 and KT879757. Similarity based annotation using BLAST analysis revealed that 5 of the isolates (KT879751, KT879752, KT879753, KT879754 and KT879755) belonged to the FMDV SAT 2 serotype. The remaining 2 isolates (KT879756 and KT879757) belonged to the FMDV SAT1 serotype. Phylogenetic analysis of these sequences using MEGA 7 showed that the viruses formed 3 clusters based on the VP1 gene sequences, 1 for SAT1 and 2 for SAT2, which implied that the SAT 2 isolates belong to 2 distinct topotypes. Our findings indicate that both the SAT2 and SAT1 serotypes are in circulation in Zimbabwe and that VP1 gene based sequencing is a useful tool for detection and identification of FMDV isolates.
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    Molecular characterization and antibiotic resistance patterns of avian fecal Escherichia coli from turkeys, geese, and ducks
    (Veterinary world, 2018-06) Dube, Nokukhanya; Mbanga, Joshua
    Background and Aim: Avian fecal Escherichia coli (AFEC) are considered to be the natural reservoir of pathogenic strains in extraintestinal infections as such characterization of AFEC gives insight into the spread of the potential pathogenic lineage. The aim of the study was to investigate the reservoirs of avian pathogenic E. coli (APEC) from fecal samples of healthy ducks, geese, and turkeys by determining the antibiotic resistance patterns of AFEC isolates from turkeys, geese and ducks and characterization of the isolates using virulence genes, plasmid profiles, and phylogenetic grouping. Materials and Methods: The disc diffusion method was used to determine antibiotic resistance of 100 AFEC isolates from turkeys (9), geese (29), and ducks (62) to 8 antibiotics. Molecular characterization of the isolates was done by multiplex polymerase chain reaction to investigate the presence of 12 virulence genes, plasmid profiling, and phylogenetic grouping based on the 16S rRNA sequences. Results: Antibiogram profiles indicated maximum resistance to cloxacillin (100%) and bacitracin (100%) for all AFEC isolates and high sensitivity to ciprofloxacin; however, all isolates exhibited multi-drug resistance. The AFEC isolates from turkeys (6) and geese (12) did not contain virulence genes. The frz (3.7%), sitD (29.6%), and fimH (92.5%) were detected in the duck isolates. None of the isolates had the KpsM, iutA, vat, sitA, hlyF, pstB, ompT, uvrY, and sopB genes. Plasmid profiling gave four plasmid profiles with the plasmids ranging from 1.5 to 55 kb. Phylogenetic analysis of 16S rRNA sequences revealed similarities between AFEC isolates from the different poultry species, as the isolates did not cluster according to avian species. Conclusion: AFEC isolates are potential reservoirs of APEC as they contain some of the virulence genes associated with APEC. Multidrug resistance is high in AFEC isolated from healthy birds. This is a public health concern.
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    Molecular identification of mycobacterium species of public health Importance in cattle in Zimbabwe by 16s rrna gene sequencing
    (BENTHAM OPEN, 2015) Padya, Leah; Chin’ombe, Nyasha; Magwenzi, Marcelyn; Mbanga, Joshua; Ruhanya, Vurayai; Nziramasanga, Pasipanodya
    Mycobacterium species are naturally found in the environment as well as in domestic animals such as cattle. So far, more than 150 species of Mycobacterium, some of which are pathogenic, have been identified. Laboratory isolation, detection and identification of Mycobacterium species are therefore critical if human and animal infections are to be controlled. The objective of this study was to identify Mycobacterium species isolated in cattle in Zimbabwe using 16S ribosomal RNA gene amplification and sequencing. A total of 134 cow dung samples were collected throughout Zimbabwe and mycobacteria were isolated by culture. Only 49 culture isolates that were found to be acid-fast bacilli positive by Ziehl-Neelsen staining. The 16S rRNA gene was successfully amplified by PCR in 41 (84%) of the samples. There was no amplification in 8 (16%) of the samples. Out of the 41 samples that showed amplification, 26 (63%) had strong PCR bands and were selected for DNA sequencing. Analysis of the DNA sequences showed that 7 (27%) belonged to Mycobacterium neoaurum, 6 (23%) belonged to Mycobacterium fortuitum, 3 (12%) to Mycobacterium goodii, 2 (1%) to Mycobacterium arupense, 2 (1%) to Mycobacterium peregrinum or M. septicum and 1 isolate (0.04%) to Mycobacterium elephantis. There were 5 (19%) isolates that were non-mycobacteria and identified as Gordonia terrae, a close relative of Mycobacterium. The study therefore provided a molecular basis for detection and identification of Mycobacterium species in animals and humans.
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    RpoB Gene-Based Characterization of Non-Tuberculous Mycobacteria in Zimbabwe
    (2017) Manjeese, Wadzanai; Muzividzi, Boniface; Mbanga, Joshua; Mufandaedza, Jonathan; Chin’ombe, Nyasha
    Aims: To characterize archived nontuberculous Mycobacteria (NTM) samples previously isolated from humans across Zimbabwe during the 2014 national tuberculosis survey. The rpoB gene of the isolates was targeted for characterization. Study Design: The research was an observational study where NTM samples previously isolated from Zimbabwean population were analysed by rpoB gene sequencing and phylogeny to identify NTM speciesPlace and Duration of Study: Department of Medical Microbiology, University of Zimbabwe between September 2015 and July 2016. Methodology: We obtained 99 NTM DNA samples from 963 NTM at NMRL, which we characterised using rpoB gene analysis after PCR amplification. The amplicons were sequenced and bioinformatics tools were used for speciation. The rpoB gene of DNA extracts from the NTM was amplified and the sequences were analysed using bioinformatics tools to identify the NTM to species level. Results: From the 99 NTM isolates, 40 were sequenced and analyzed. The NTM were identified as belonging to 13 species. The species were M. palustre (14.8%), M. aroisense (29.6%), M. parascrofulaceum (3.7%), M. arupense (7.4%), M. asiaticum (3.7%), M. malmoense (3.7%), M. lacus (3.7%), M. avium (7.4%), M. nonchromogenicum (3.7%), M. gordonae (3.7%), M. aromaticivorans (3.7%), M. novocastrense (3.7%), M. bourgelatii (3.7%). One sample (3.7%) belonged to Mtb complex species (3.7%) and another one (3.7%) was closely related to S. oryzae. The most common species belonged to M. aroisense and M. palustre. The species showed a high degree of rpoB sequence diversity. Sequence analysis of the rifampicin resistance determining region (RRDR) showed the existence of only silent mutations. Conclusion: Species of NTM from Zimbabwe showed a high degree of rpoB gene sequence diversity. This characteristic feature can therefore be used in diagnosis and identification of NTM in clinical specimens
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    A Study of Scavenging Poultry Gastrointestinal and Ecto-parasites in Rural Areas of Matebeleland Province, Zimbabwe
    (Asian Network for Scientific Information, 2010) Dube, S.; Zindi, P.; Mbanga, Joshua; Dube, C.
    A study was carried out to determine endo and ecto-parasites in Matebeleland North and South from free range chickens (Gallus domesticus). Only adult chickens were selected for determination of parasite. For intestinal parasites microscopic studies of eggs and faecal egg counts were done using the salt floatation technique. The endo parasites encountered in the study were Tetrameres americana, Acuaria hamulosa, Ascaridia galli, Heterakis gallinarum, H. dispar, Allodapa suctoria, Capillaria annulate, Raillietina echinobothrida and R. tetragona. A commercially prepared insecticide constituted as follows (0.02% Tetamethrin, 0.03% pramethrin and 0.034% Imiprothrin) was applied for 2 seconds and feathers were then gentle unruffled so that ectoparasites could be counted and identified. Ecto parasites recorded in this study were Menopon gallinae, Menacanthus stramineus, Dermanyssus gallinae, Argas persicus, Ornithonyssus bursa, Cnemidocoptes mutans, Echidnophaga gallinacean, Gonocoites gallinae and Gonocoites hologester. The birds under study showed slow growth, poor egg hatching. Parasites should have contributed substantially to this poor growth although not single handedly.
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    Virulence factors and antibiotic resistance patterns of uropathogenic Escherichia coli
    (Academic Journals, 2014-10-22) Mbanga, Joshua; Mudzana, Raymond
    Urinary tract infections (UTIs)are one of the most common infections in humans and the commonest cause is Uropathogenic Escherichia coli (UPEC). UPEC possess various virulence factors which enable them to survive and grow in urine and other extra-intestinal environments. Similarly, avian pathogenic E.coli (APEC) are known for their ability to cause extra-intestinal diseases in birds. Since APEC and UPEC may encounter similar challenges when establishing infection in these locations, they may share a similar content of virulence genes and capacity to cause disease. In this study, 40 UPEC isolates were obtained from patients with suspected UTIs. Multiplex polymerase chain reaction (PCR) was then used to screen the 40 UPEC isolates for 12 virulence genes usually associated with APEC isolates. The iutA (35%), frimH (32,5%), VAT (17.5%), sitA (17.5%), sitD (15%), hlyF (12,5%), pstB (10%) and frz (7.5%) genes were detected. None of the isolates had the kpsM, ompT, unvrY and sopB genes. Antibiotic resistance patterns were also determined for all 40 isolates. A high resistance to ampicillin (90%) and tetracycline (75%) accompanied by a high sensitivity to gentamycin (82.5%) and nitrofurantoin (62.5%) was observed. Eleven multi-drug resistance patterns were observed in 65% (26/40) of the isolates. The studied UPEC isolates were shown to possess APEC associated virulence genes at low percentage frequencies suggesting a slight overlap in virulence genotypes. Antibiotic resistance patterns suggest surveillance programs to monitor drug resistance should be put in place.
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    Virulence gene profiles of avian pathogenic Escherichia coli isolated from chickens with colibacillosis in Bulawayo, Zimbabwe
    (SCIELO South Africa, 2015-04-07) Mbanga, Joshua; Nyararai, Yvonne O.
    Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC), is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR) assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%), fimH (33.3%) and hlyF (24.4%). The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.