Publications


2017

and Njue LG., Ombui JN., KLWGJKMJO.  2017.  Identification of antimicrobial compounds in garlic grown in Laikipia county.. Journal of Agricultural research and review,. 5(5):636-643.
and Njue LG., Ombui JN., KLWGJK.  2017.  Assessment of effectiveness of garlic extract from Laikipia County on shelf life of meat. Journal of Agricultural Economics, Extension and Rural Development. 5(5):632-641.

2016

and Kipronoh A.K., Ombui JN. Binepal YS., WGTKHKHOEK.  2016.  Risk factors associated with contagious caprine pleuropneumonia in goats in pastoral areas in Rift Valley region of Kenya. . Preventive Veterinary Medicine . 132:107-112.
and Kuria Alex, OJNOA.  2016.  Tannin analysis of selected plants from Laikipia County, Kenya. Journal of the Society for Leather Technologists and Chemists, . 100:73-76.
and Kuria Alex, OJNOA.  2016.  Quality evaluation of leathers produced by selected vegetable tanning materials from Laikipia County, Kenya. Journal of Agriculture and Veterinary Sciences, 9(4): 13-17. 9(4):13-17.
and Ngugi, A., OJNGJMLKWEAM.  2016.  Evaluation of Economic losses from the hides and skins subsector in Wajir County, Kenya. . Journal of Agriculture and Veterinary Science. 9(7):41-44.

2015

and Sirma A J; Ouko E. O., Gatwiri M., MMOKK’etheCIJN.  2015.  Prevalence of Aflatoxin contamination in cereals in Nandi County, Kenya. . International journal of Agricultural Sciences and Veterinary Medicine. 3(3):55-63.
and Kipronoh A.K., Ombui, KHKBYSGWHOJNE.  2015.  Prevalence of contagious caprine pleura-pneumonia in pastoral flocks of goats in the rift valley region of Kenya. . Animal Health and Production, . 48(1):151-155.

2014

Njue, L, Kanja LW, Ombui JN, Nduhiu JG, Obiero D.  2014.  EFFICACY OF ANTIMICROBIAL ACTIVITY OF GARLIC EXTRACTS ON BACTERIAL PATHOGENS COMMONLY FOUND TO CONTAMINATE MEAT. East African Medical Journal. 91(12):442.abstract.pdf
and Jackson N Ombui, GMGMEA.  2014.  ASSESSMENT OF PERFORMANCE AND COMPETITIVENESS OF SOMALILAND LIVESTOCK SECTOR USING VALUE CHAIN ANALYSIS. International Journal of Agricultural Sciences and Veterinary Medicine. 2(1)abstract.pdf

2013

Kikuvi, GM, Ole-Mapenay, I. M; Mitema ES, Ombui JN.  2013.  Antimicrobial resistance in Escherichia coli isolates from faeces and carcass samples of slaughtered cattle, swine and chickens in Kenya. Abstract

Two hundred and thirty five Escherichia coli isolates from cattle, pigs and chickens were investigated for their resistance to seven antimicrobials by the disc diffusion method. Minimum inhibitory concentrations were determined for 154 isolates showing resistance to at least one of the antimicrobials tested. Resistance was found in 65.5% and multi-resistance (resistance to = 2 antibiotics) in 37.9% of the isolates. Resistance was highest in the isolates from chickens (74.0%), followed by pigs (64.8%) and cattle (61.3%). The most common resistance was to ampicillin, streptomycin, tetracycline, sulphamethoxazole/trimethoprim, and kanamycin (42.5-11.9%). Resistance to kanamycin, sulphamethoxazole/trimethoprim, and tetracycline was significantly lower in cattle (2.5-7.5%) than in the other species (12.0-40.0%) (p < 0.01). Resistance to streptomycin and ampicillin were significantly higher in cattle and pigs respectively (p < 0.01). Similar resistance rates were observed among the faecal (29.9%) and carcass swab (33.1%) isolates. Forty resistance patterns were recorded of which only 5 (12.5%) were common among the isolates studied. This study shows that multi-drug resistant E. coli isolates are prevalent in cattle, pigs and chickens in Kenya and that a considerable proportion of E. coli isolates from fresh cattle and pig carcasses is resistant to a variety of antimicrobial agents. Differences in the rates and patterns of resistance were noted, perhaps reflecting differences in antibiotic use regimens among these species. It is recommended that the use of antimicrobials in food animals should follow prudent use guidelines to minimize the selection of resistant bacteria and that slaughter hygiene should be improved to minimize the risk of transfer of antimicrobial resistant bacteria to humans.

2012

Kinyanjui, W, Massimo C, Muchina MSJ, Goad AR, Joseph GM, Jackson ON, Eddy MM.  2012.  Commercialization of meat trade: the potential role of private sector and capacity building in quality assurance in meat export trade from regions of Somalia. International Research Journal of Microbiology. 3(2141-5463):86-93.
Francis Gakuya1, Jackson Ombui2, JH3 NM4 GM2 WO2 DM1 SA.  2012.  Knowledge of Mange among Masai Pastoralists in Kenya. Plos one. 7(8):1-7.abstract.pdf
and FRANCIS GAKUYA1*, JACKSON OMBUI2, NDICHUMAINGI3 GERALDMUCHEMI2 WILLIAMOGARA2 RAMÓNSORIGUER4 SAMERALASAAD4C 5.  2012.  Sarcoptic mange and cheetah conservation in Masai Mara (Kenya): epidemiological study in a wildlife/livestock system. Parasitology. :1-9.summary.pdf

2011

and Maloba, F., KGOHNJMGJ.  2011.  Astrocytosis as a biomarker for late stage human African Trypanosomiasis in the vervet monkey mode. Scientia Parasitologica. 12:53-59.

2010

and Wamalwa K., Castiello M., OJNGJM.  2010.  Investigation of hygiene standard of carcasses slaughtered in five local slaughterhouses of Somaliland, Somalia. Proceedings of the 7th Bieannual Scientific Conference.
Kikuvi, G. M., OMJNSM.  2010.  Serotypes and antimicrobial resistance profiles of Salmonella isolates from pigs at slaughter in Kenya. J Infect. Dev. Ctries. 4:243-248.

2009

2008

NYARONGI, PROFOMBUIJ.  2008.  Kikuvi G. M., Ombui, J. N., Mitema, E. S., Schwartz, S and Kehrenberg C. (2008). Genetic basis, transferability and linkage of streptomycin and sulphonamide resistance genes in Escherichia coli from foods of animal origin in Kenya, Bull. Anim. Hlth. Prod.. nim. Hlth. Prod. Afr.56(1): 56-66. : University of Nairobi Press Abstract
The genetic basis and transferability of streptomycin and sulphonamide resistance was studied in 23 Escherichia coli isolates from food of animal origin in Kenya. Physical linkage of the streptomycin resistance gene strA with sulhonamide resistance gene Sul2 was investigated by PCR and confirmed by sequencing. Two small plasmids of 6kb (pSSGK1) and 8kb (pSSTGK1) identified by transformation to mediate resistance to at least streptomycin and sulphonamide were restricted in order to define their relatedness. Their restriction maps were compared to one another and with the maps of other plasmid from E. coli known to mediate these resistance properties. Streptomycin resistance was based on the expression of the strA, strB and or aadA1 genes, while sulphonamide resistance was encoded by the sul2 or sul1 gene. The strA, strB and sul2 genes were transferable via conjugation and transformation. Hysically lnked sul2 and strA genes were present in both plasmid pSSGK1 and pSSTK1. Plasmids pssgk1 and psstgk1 were different from each other, but similar respectively to sulphonamide/streptomycin and sulphonamide/streptomycin/tetracycline resistance plasmids described previously in uropathgenic E. coli from humans. Conjugation of plasmids encoding strptomycin and sulphonamide resistance may be one mechanism for the wide dissemination and persistence of these resistances among E. coli from food animals in Kenya. Physcal linkage of the plasmid-borne strA and sul2 genes would facilitate the spread of these genes by co-selection during selective pressure imposed by the use either of the two antimicrobials and highlights the need for the prudent use of streptomycin or sulphonamides in animal husbandry.
NYARONGI, PROFOMBUIJ.  2008.  Ombui, J.N., Nduhiu J. G and Gicheru, M. M (2008). Direct detection of Bacillus cereus enterotoxin genes in food by multiplex polymerase chain reaction. International Journal of Integrative Biology, 2(3):172-181.. International Journal of Integrative Biology, 2(3):172-181.. : University of Nairobi Press Abstract
This study evaluated a direct multiplex PCR to detect food contamination  with enterotoxigenic Bacillus cereus (B. cereus) in comparison with culture and multiplex gene detection using colonies. Detection of B. cereus  enterotoxin genes was done on artificially contaminated and ready-to- eat market foods including cooked rice, pasteurized milk and cheese. Of the 108 food samples analysed, 51(47.2 % were found to be contaminated with enterotoxigenic B. cereus  by culture and enterotoxin detection by multiplex PCR, but only 14(12.9%) of them were found to be contaminated with enterotoxigenic B. cereus by direct multiplex PCR. B. cereus enterotoxin genes were detected only in artificially contaminated and ready-to-eat market foods with bacterial counts of equal or more than 4000 (4x103 ) cfu/ml for both pasteurized milk and cheese and equal or more than 40,000 cfu/g for cooked rice. Since high contamination of food with B. cereus (107 cfu/g) has been associated with food poisoning, this technique can be used to identify foods suspected to cause food poisoning without culture and identification of B. cereus  Detection of any of the enterotoxin genes will indicate contamination of foods with enterotoxigenic B. cereus group.

2007

NYARONGI, PROFOMBUIJ.  2007.  Kikuvi, GM., Ombui, JN., Mitema, SE and Schwarz, S. (2007). Antimicrobial Resistance in Salmonella serotypes Isolated from Slaughter Animals in Kenya. East African Medical Journal, 84(5):233-239.. East African Medical Journal, 84(5):233-239.. : University of Nairobi Press Abstract
Objectives: To isolate Salmonella from food animals and characterize the antimicrobial resistance of the isolates. Design: A random sampling of slaughter animals was carried out Setting: Department of Public Health, pharmacology and Toxicology, University of Nairobi, Kenya and Institute for Animal Breeding, Neusatadt- Mariensee, Germany. Subjects: Two hundred and eighty five samples, including faecal samples and carcass, cloacal and pharyngeal swab samples were analysed. Results: Sixteen (5.6%) of 285 samples were positive for Salmonella enterica sub-species enterica serovars, namely Saintpaul (S. saintpaul), Braenderup (S. Braenderup), and Heidelberg (S. Heidelbebrg) were identified with S. Saintpaul being the predominant serovar. Antimicrobial resistance was found in 35.7% of all the isolates. The S. Heidelberg  isolates were susceptible to all antimicrobial agents tested. Multidrug resistance was found in 7.1 % of the resistant Salmonella isolates.  Plasmids were only detected in S. Heidelberg. Ampicillin resistance was based on expression of blaTEM gene, while chloramphenicol, streptomycin and tetracycline resistance were encoded by the genes catA1, strA and tet(A) respectively. Conclusion: Pigs may serve as reservoirs of antimicrobial resistant salmonella and slaughterhouse cross-contamination of pork may be a food safety risk. We recommended that slaughterhouse hygiene be improved to minimise contamination of pig carcasses.
NYARONGI, PROFOMBUIJ.  2007.  Kikuvi G.M, Schwarz, S., Ombui, J.N., Mitema, E.S and Kehrenberg, C.(2007). Streptomycin and Chloramphenicol Resistance genes in Escherichia coli isolates from cattle, pigs and chicken in Kenya. Microbial Drug Resistance 31(1): 62-68.. Microbial Drug Resistance 31(1): 62-68.. : University of Nairobi Press Abstract
The aims of this study were to determine the genetic basis of streptomycin and chloramphenicol resistance in 30 Escherichia coli isolates from food animals in Kenya and the role of plasmids in the spread of resistance. Seven of the 29 streptomycin-reistant isolates harboured both the str A and StrB genes. Twenty one of the isolates had the strA, strB and aadAI genes. The strA gene was disrupted by a functional trimethoprim gene, dfrA14 in 10 of the 21 isolates harbouring the three streptomycin resistance genes. Physical linkage of intact strA and sul2 genes were found in two different plasmids from four isolates. Linkage of cassette-borne aadAI and dfrAI genes in class 1 integrons was found in two of the isolates. Chloramphenical resistance was due to the gene catA1 in  all the chloramphenicol resistant isolates. The strB, strA and catA1 genes were transferable by conjugation and this points to the significance of conjugative resistance plasmids in thespread and persistence of streptomycin and chloramphenicol resistance in food animals in Kenya.
NYARONGI, PROFOMBUIJ.  2007.  Ombui, J. N and Mathenge, J. M (2007). A Comparison of the Reverse Passive Latex Agglutination and Enzyme Linked Immunosorbent Assay Techniques for Detection of Staphylcoccal Enterotoxins. The Kenya Veterinarian, 31(1) : 20-26.. The Kenya Veterinarian, 31(1) : 20-26.. : University of Nairobi Press Abstract
This study evaluated a direct multiplex PCR to detect food contamination with enterotoxigenic Bacillus cereus (B. cereus) in comparison with culture and multiplex gene detection using colonies. Detection of B. cereus enterotoxin genes was done on artificially contaminated and ready-to- eat market foods including cooked rice, pasteurized milk and cheese. Of the 108 food samples analysed, 51(47.2 % were found to be contaminated with enterotoxigenic B. cereus by culture and enterotoxin detection by multiplex PCR, but only 14(12.9%) of them were found to be contaminated with enterotoxigenic B. cereus by direct multiplex PCR. B. cereus enterotoxin genes were detected only in artificially contaminated and ready-to-eat market foods with bacterial counts of equal or more than 4000 (4x103 ) cfu/ml for both pasteurized milk and cheese and equal or more than 40,000 cfu/g for cooked rice. Since high contamination of food with B. cereus (107 cfu/g) has been associated with food poisoning, this technique can be used to identify foods suspected to cause food poisoning without culture and identification of B. cereus Detection of any of the enterotoxin genes will indicate contamination of foods with enterotoxigenic B. cereus group.

2006

NYARONGI, PROFOMBUIJ.  2006.  Mapenay, I. M. Kikuvi, GM., Mitema, E. S and Ombui, J. N (2006). Antibiotic Resistance of Escherichia coli Isolated from Healthy Animals in Kenya. The Kenya Veterinarian 30(1): 22 -26.. The Kenya Veterinarian 30(1): 22 -26.. : University of Nairobi Press Abstract
Antimicrobial resistance profile of 204  Escherichia coli isolates of bovine, swine and poultry origin to eight (8) antimicrobial agents was studied. Antimicrobial susceptibility tests were determined using the disk diffusion technique. Full sensitivity to all the eight antimicrobial agents in the test panel was observed in 46 % of all isolates. Resistance to at least one antimicrobial was observed in 10% of the isolates, while multi-drug resistance (resistance to two or more antibiotics) was observed in 26% of the isolates. Generally, resistance was significantly higher for isolates from swine and poultry than in cattle. The overall prevalence was 22% for sulphamethoxazole, 21% for cotrimoxazole, 19% for  ampicillin, 14% for tetracycline, 9% for stretomycin, 4.4% for chloramphenicol and 2.5% for kanamycin. No resistance was observed for gentamycin. It was concluded from the study that healthy food animals form a reservoir of multiple resistant E. coli which may be transmitted to  humans through the food chain. Thus, continued surveillance of E. coli obtained from food production continuum is merited to identify emerging antimicrobial-resistant phenotypes.

2005

NYARONGI, PROFOMBUIJ.  2005.  Prevalence of enterotoxigenic Bacillus cereus and its enterotoxins in milk and products in and around Nairobi. journal. : University of Nairobi Press Abstract
Objectives: To determine the prevalence of enterotoxigenic Bacillus cereus (B. cereus) and enterotoxingens in milk and milk products. Design: A random sampling of milk products was carried out. Setting: Market milk and milk products were collected from retail shops in Nairobi and analysed for contamination with enterotoxigenic B. cereus and its enterotoxins using reverse passive latex agglutination and TECRA ELISA immunoassay test. Subjects: Ninety six milk samples including 36 raw milk, 42 pasteurized milk, 10 yoghurt and eight fermented milk samples. Forty seven B. cereus isolated from milk and milk products. Main outcome measures: Isolation of enterotoxigenic B. cereus from milk and milk products and detection of B. cereus hemolytic (hemolysin BL) and non-hemolytic enterotoxins in milk. Results: Fifty seven percent of the samples were contaminated with B. cereus. Eighty one percent (38 out of 47) of the isolates produced non-hemolytic enterotoxins, while 25(53.2%) of the isolates produced hemolysin BL. Eigtheen (38.3%) of the isolates produced both hemolysin BL and non-henolytic enterotoxins. About 14.3% of the pasteurized milk samples tested positive for non-hemolytic enterotoxin. Conclusions: Enterotoxigenic B. cereus and enterotoxins occur in market milk and their presence poses a potential risk of causing food poisoning. The risk can be reduced if milk products undergoes thorough quality control checks and be kept always at below 4oC till consumption. Post pasteurization contamination which is commonly blamed for spoilage of milk products by B. cereus is not necessarily the most important source of the organism.
NYARONGI, PROFOMBUIJ.  2005.  Immunoassay and polymerase chain reaction techniques for detection of enterotoxigenicity of Bacillus cereus. journal. : University of Nairobi Press

2004

NYARONGI, PROFOMBUIJ.  2004.  Prevalence and economic importance of Fascioliasis in cattle, sheep and goats in Kenya. journal. : University of Nairobi Press Abstract
A 10-year (1990-1999) retrospective study using post mortem records was carried out at veterinary Department Headquarters Kabete to determine the prevalence and economic importance of fasciolosis in cattle, sheep and goats in Kenya. Records from abattoirs from 38 districts in 7 provinces of Kenya were examined. Fasciolosis prevalence was calculated using an average weight of (3kg) for cattle and (0.5kg) for sheep and goats. The monetary loss occasioned by condemnation of Fasciola infected livers was calculated using and a market price of US$ 2.0 per Kg. Out of 5,421,188 cattle, 1,700,281 sheep and 2,062,828 goats slaughtered, 427,931 cattle (8%), 61,955 sheep (3.6%) and 48,889 goats (2.4%) were infected with Fasciola. The highest prevalence was recorded in Western province (16% for cattle, 10% for sheep and 9% for goats). The lowest was in Coast province (3.5% cattle, 0.74% sheep and 0.5% goats). The economic loss due to condemnation of infected livers from cattle, sheep and goats was estimated to be US$ 2.6 million, US$ 61,955 and US$ 48,889 respectively. It was concluded that fasciolosis is prevalent in cattle, sheep and goats in Kenya and is a major cause of economic loss, as a result of condemnation of infected livers.

2003

2002

NYARONGI, PROFOMBUIJ.  2002.  The prevalence and economic importance of bovine fasciolosis in Kenya. An analysis of abattoir data. journal. : University of Nairobi Press Abstract
A retrospective study covering a period of 10 years(1990-1999) was carried out using post-mortem meat inspection records at the veterinary Department Headquarters in Kabete to determine the prevalence and economic importance of bovine fasciolosis in   fasciolosis was calculated as the number of cattle found to be infected with Fasciola expressed as a percentage of  the total number of cattle slaughtered. Using the average weight and market price of bovine liver, the monetary loss occasioned by condemnation of Fasciola infected livers was calculated. A survey was also was also carried out at Dagoretti slaughterhouse comples in Nairobi to determine the relative occurrence of F. gigantica and F. hepatica in slaughter cattle. Cattle slaughtered at Dagoretti slaughterhouse originate from all parts of the country. A total of 5 421188 cattle were slaughtered in the seven provinces of Kenya during the 10 year period and 427 931(8%) of these cattle were infected with Fasciola. The region with the highest prevalenve of fasciolosis was Western Province (16%) followed in a descending order, by Eastern province (11%), Nyanza Province (9%), Rift Valley Province (8%), Central Province (6%), Nairobi Province (4%) and Coast Province (3.5%). The total economic loss incurred by the country during the 10-year period as a result of condemnation of livers was approximately US$ 2.6 million. The total annual economic losses during this period ranged from US$ 0.2-0.3 million.  The highest total economic losses for the 10-year period were recorded in Western Province (US$0.8 million) and Central Province (US$ 0.7 million). A total of 1584 cattle originating from five out of eight provinces of Kenya were slaughtered at Dagoretti slaughterhouse over a period of two months of which 147(9.3%) were infected with liver flukes. All the liver flukes obtained from the infected livers were identified as F. gigantica. It was concluded that fasciolosis is prevalent in cattle in all provinces of Kenya and it causes great economic losses as a result of condemnation of infected livers and that F. gigantica is the main species of liver flukes affecting cattle in Kenya. Local climatic factors, cattle trade, rustling and population numbers, and presence of snail intermediate hosts are probably the main factors influencing the incidence of the disease in the various regions of the country.

2001

NYARONGI, PROFOMBUIJ, MUCHAI PROFKAGIKOM, ARIMI PROFMUTWIRIS.  2001.  Food-borne diseases in Kenya. journal. : University of Nairobi Press Abstract
Objectives: To determine the occurrence of food borne disease outbreaks in Kenya and the efforts employed to combat them. Design: A cross-sectional survey. Setting: Forty two districts in Kenya between 1970 and 1993. Study subjects: Food-borne disease outbreak episodes due to Staphylococcus aureus, Clostridium perfringens, Clostridium botulinum, Bacillus cereus, Escherichia coli, campylobacter jejuni, Yersinia enterocolitica, Listeria monocytogenes, chemicals, aflatoxins, plant and animal poisons. Outcome measures: Number and aetiological causes of food-borne disease outbreaks reported in the study period. Results: Thirty seven food poisoning outbreaks were reported to the Ministry of Health from various parts of the country in the study period 1970 to 1993, and only 13 of these involving a total of 926 people were confirmed to be due to particular aetiological agents. Foods that were involved included milk and milk products, meat and meat products, maize flour, bread scones and other wheat products, vegetables and lemon pie pudding. A high number of food poisoning cases were treated as outpatients in various health facilities. Conclusions: Under-reporting, inadequate investigation of outbreaks and inadequate diagnostic facilities suggest that food-borne disease outbreaks are more that is recorded by the Ministry of Health.
NYARONGI, PROFOMBUIJ, MUCHAI PROFKAGIKOM, ARIMI PROFMUTWIRIS.  2001.  Molecular Epidemiology of Bacillus cereus food poisoning. journal. : University of Nairobi Press Abstract
Objectives: To investigate the potential use of DNA techniques in epidemiological diagnosis of Bacillus cereus food poisoning. Subjects: Fifty six B. cereus isolates from milk were studied. Design: The 56 B. cereus isolates were characterized into enterotoxin positive(27 islates) and enterotoxin negative(29 isolates) using reverse passive latex agglutination technique. Setting: Plasmid and genomic DNA were isolated from all the B. cereus isolates. The plasmid DNA was analysed by gel electrophoresis, while genomic DNA was used for restriction endonuclease and toxin gene analyses. Main outcome measures: Plasmid profile analysis, restriction endonuclease analysis of genomic DNA, and test for bceT and hblA genes by polymerase chain reaction and gene probing. Results: Seventy two per cent of the isolates contained one to five plasmids of molecular sizes between 0.1 to 60 Mda. Restriction analysis of genomic DNA gave different restriction patterns among enterotoxin positive and enterotoxin negative isolates.  Polymerase chain reaction assay detected bceT gene in 41.1% of the isolates, 16% of which tested positive for enterotoxin with B. cereus enterotoxin reverse passive latex agglutination(BCET-RPLA) kit, while hblA gene was detected in all the enterotoxin positive isolates. BceT and hblA gene probes detected the respective genes in all the isolates that also tested positive for toxin genes by polymerase chain reaction. Conclusion: DNA techniques provide an alternative approach to the diagnosis of enterotoxigenic B. cereus.

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