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Newaj-Fyzul A, Mutani A, Ramsubhag A, Adesiyun A. Prevalence of bacterial pathogens and their anti-microbial resistance in Tilapia and their pond water in Trinidad. Zoonoses Public Health 2008; 55:206-13. [PMID: 18387142 DOI: 10.1111/j.1863-2378.2007.01098.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Trinidad, Tilapia (Oreonchromis spp.) is one of the most important fresh water food fish and the number of farms has been increasing annually. A study was conducted in the local tilapia industry to determine the microbial quality of pond water, prevalence of bacterial pathogens and their anti-microbial resistance using the disk diffusion method. Seventy-five apparently healthy fish and 15 pond water samples from three of the four commercial tilapia fish farms in the country were processed. The 202 bacterial isolates recovered from fish slurry and 88 from water, belonged to 13 and 16 genera respectively. The predominant bacteria from fish slurry were Pseudomonas spp. (60.0%), Aeromonas spp. (44.0%), Plesiomonas (41.3%) and Chromobacterium (36.0%) (P < 0.05; chi(2)) compared with isolates from pond water where Bacillus spp. (80.0%), Staphylococcus spp., Alcaligenes spp. and Aeromonas spp. (60.0%) were most prevalent (P < 0.05; chi(2)). Using eight anti-microbial agents, to test bacteria from five genera (Aeromonas, Chromobacterium, Enterobacter, Plesiomonas and Pseudomonas), 168 (97.1%) of 173 bacterial isolates from fish slurry exhibited resistance to one or more anti-microbial agents compared with 47 (90.4%) of 52 from water (P > 0.05; chi(2)). Resistance was high to ampicillin, 90.2% (158 of 173), erythromycin, 66.5% (115 of 173) and oxytetracycline, 52.6%, (91 of 173) but relatively low to chloramphenicol, 9.8% (17 of 173) and sulphamethoxazole/trimethoprim, 6.4% (11 of 173) (P < 0.05; chi(2)). For pond water isolates, the frequency of resistance across bacterial genera ranged from 75% (nine of 12) for Chromobacter spp. to 100% found amongst Enterobacter spp. (six of six), Plesiomonas spp. (nine of nine) and Pseudomonas spp. (eight of eight) (P < 0.05; chi(2)). Resistance was generally high to ampicillin, 78.8% (41 of 52), erythromycin, 51.9% (27 of 52) and oxytetracycline, 34.5% (18 of 52) but low to sulphamethoxazole/trimethoprim, 7.7% (four of 52) and norfloxacin, 3.8% (two of 52) (P < 0.05; chi(2)). It was concluded that the rather high prevalence of bacterial pathogens in tilapia along with their high prevalence of resistance to anti-microbial agents might pose therapeutic problems as well as health risk to consumers. The microbial presence and their anti-microbial resistance in the tilapia industry are being reported for the first time in the country.
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Affiliation(s)
- A Newaj-Fyzul
- School of Veterinary Medicine, Faculty of Medical Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies
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Newaj-Fyzul A, Adesiyun AA, Mutani A, Ramsubhag A, Brunt J, Austin B. Bacillus subtilis AB1 controls Aeromonas infection in rainbow trout (Oncorhynchus mykiss, Walbaum). J Appl Microbiol 2007; 103:1699-706. [DOI: 10.1111/j.1365-2672.2007.03402.x] [Citation(s) in RCA: 234] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Adogwa A, Mutani A, Ramnanan A, Ezeokoli C. The effect of gastrointestinal parasitism on blood copper and hemoglobin levels in sheep. Can Vet J 2005; 46:1017-21. [PMID: 16363328 PMCID: PMC1259146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Endoparasitism is a problem in Trinidad, as it is in most tropical countries. Parasite infection has been suspected to contribute to the pathogenesis of swayback disease (which is also prevalent in Trinidad), but the mode of action has not been clearly defined, although it has been suggested that parasites interfere with the absorption of copper from the gastrointestinal tract. The objectives of the study were to assess the effect of endoparasitism on blood copper levels and hemoglobin (Hb) concentration in sheep in Trinidad. Copper was administered intramuscularly to parasite infected and noninfected animals. The results showed that parasitism has a depressing effect on blood copper and Hb levels, even when administered parenterally. It is concluded that parasitism can aggravate existing hypocupremia and possibly influence the expression of swayback disease.
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Affiliation(s)
- A Adogwa
- School of Veterinary Medicine, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, West Indies.
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Abstract
Peripheral blood leukocytes from different animals were isolated from whole blood and maintained in Dulbeco's medium containing homologous serum without antibiotics. After 72 hrs microscopic examination of these cells showed that most animals were infected with Ehrlichia. Observation of thin blood smears from the same animals showed that only two were positive for Ehrlichia. The results of this investigation show that leukocyte culture is superior to the traditional thin blood film method in the detection of Ehrlichia and that asymptomatic carriers are easily detected. The method is inexpensive and does not require specific cell lines although it is necessary to use sterile sera.
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Affiliation(s)
- A Mutani
- School of Veterinary Medicine, The University of The West Indies, Saint Augustine, Trinidad and Tobago.
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Adesiyun AA, Kaminjolo JS, Ngeleka M, Mutani A, Borde G, Harewood W, Harper W. A longitudinal study on enteropathogenic infections of livestock in Trinidad. Rev Soc Bras Med Trop 2001; 34:29-35. [PMID: 11340494 DOI: 10.1590/s0037-86822001000100005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A longitudinal study was conducted on selected livestock farms to determine the prevalence of enteropathogens in diarrhoeic and non-diarrhoeic animals. The enteropathogens assayed from faecal samples and rectal swabs were bacteria (Escherichia coli, Campylobacter spp. Salmonella spp. and Yersinia enterocolitica), parasites (coccidia, gastrointestinal nematodes and Cryptosporidium spp.) and viruses (group A rotavirus and parvovirus). The prevalence of the enteropathogens in various animal species was related to age and month of the year. Generally, younger animals presented a higher prevalence of infection by enteropathogens than older animals while most infections occurred between the months of January and April.
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Affiliation(s)
- A A Adesiyun
- School of Veterinary Medicine, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad.
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Ingonga P, Mbati PA, Anjili CO, Mutani A, Wishitemi B, Odongo S, Robert LL, Githure JI. The effect of immune sera from hamsters immunized with sandfly gut and whole body extract antigens on the fecundity and mortality of Phlebotomus duboscqi (Diptera: Psychodidae). Acta Trop 1996; 60:269-79. [PMID: 8659326 DOI: 10.1016/0001-706x(95)00132-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Phlebotomus duboscqi were fed on hamsters previously immunized with different concentrations of homogenized crude sandfly gut antigen and supernatant obtained from whole body extract. The humoral response in the rodents was quantified at different times post-immunization by the enzyme-linked immunosorbent assay. Sandflies were fed on either immunized or saline control hamsters and the effect of the blood meals on sandfly feeding, survival and fecundity was investigated. The humoral response in immunized hamsters as measured by the presence of P. duboscqi-specific IgG antibodies was significantly greater (P < 0.05) as compared to the controls. This difference was noted in sera collected on 15 and 25 days post-immunization. Sandflies fed on immunized hamsters had a significantly higher mortality (P < 0.05) and decreased egg production (P < 0.05) than those fed on unimmunized control hamsters.
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Affiliation(s)
- P Ingonga
- Department of Zoology, Moi University, Eldoret, Kenya
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Khaemba BM, Mutani A, Bett MK. Studies of anopheline mosquitoes transmitting malaria in a newly developed highland urban area: a case study of Moi University and its environs. East Afr Med J 1994; 71:159-64. [PMID: 7956862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Throughout the duration of these studies, Anopheles gambiae was the only mosquito species recovered at the study site. It bred in several habitats, showing strong preference for temporary waterponds contained in a variety of reservoirs created through man's construction activities. The dams as permanent water bodies were the most favoured perennial breeding habitat as opposed to swamps. Of the 393 mosquitoes tested, a very small percentage (0.76%) was infected with sporozoites (0.51%) and oocysts (0.25%). The overall human malaria rate was 5.3%. Males (3.3%) were apparently more parasitaemic than the females (2.0%). The difference was not significant (P > 0.05), indicating that the infection was not sex-linked. Of the four known malarial parasites, the only two species that were diagnosed were Plasmodium malariae (Laveran) and Plasmodium falciparum (Welch), the latter species being the most prevalent (86.2%). Only 3 cases of mixed malaria infections were diagnosed. Apparently, the infections of P. falciparum were the most prevalent in age groups below 16 years accounting for 96.6% of all the infections.
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Affiliation(s)
- B M Khaemba
- Department of Zoology, Moi University, Eldoret, Kenya
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Abstract
Host resistance, accompanied by demonstrable anti-tick antibodies, developed in groups of rabbits that were infested repeatedly with different numbers of Rhipicephalus evertsi evertsi larvae. This resistance was associated with a drastic reduction in the number of ticks that attached but not in the ability to feed and moult by immatures already established on the hosts. Furthermore, resistance reduced to below 50% the proportion of nymphs which emerged from the larvae applied to the three host groups. Nymphs weighing 5-9.9 and 15-19.9 mg moulted to give mainly males or females respectively. The proportion of males and females which moulted from the remaining weight categories was variable. Anti-tick antibodies were detected by enzyme-linked immunosorbent assay as early as 7 days after primary infestation in all hosts. The titres plateaued after the second challenge and declined drastically during the fifth infestation. No appreciable differences were observed in the antibody responses stimulated by different challenge regimens.
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Affiliation(s)
- B C Njau
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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Njau BC, Nyindo M, Mutani A. Immunological responses and the role of the paralyzing toxin in rabbits infested with Rhipicephalus evertsi evertsi. Am J Trop Med Hyg 1986; 35:1248-55. [PMID: 3789273 DOI: 10.4269/ajtmh.1986.35.1248] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Twenty-nine rabbits were exposed to 4 infestations with 20, 50, and 100 adult red-legged ticks (Rhipicephalus evertsi evertsi). Upon challenge, 16 rabbits (55%) contracted paralysis, and 14 of these (88%) died. Most deaths occurred in rabbits challenged with 100 ticks. Immunity to paralysis and subsequent resistance to tick feeding developed in the hosts that survived the initial challenge. Antibody titers to a salivary gland antigen increased progressively as determined by the following tests: passive hemagglutination, agar gel double immunodiffusion, and enzyme-linked immunosorbent assay. Rabbits challenged with 20 ticks displayed declining titers with advanced frequency of challenge and few of the rabbits in this group developed paralysis. There was no decline in antibody titers in groups of rabbits exposed to 50- and 100-tick loads. It is suggested that a certain quantum of antigen injected by the ticks is necessary for induction of immunity to paralysis.
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Mutani A, Christensen NO, Frandsen F. A study of the biological characteristics of a hybrid line between male Schistosoma haematobium (Dar es Salaam, Tanzania) and female S. intercalatum (Edea, Cameroun). Acta Trop 1985; 42:319-31. [PMID: 2868634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The viability of a hybrid between male Schistosoma haematobium (Dar es Salaam, Tanzania) and female S. intercalatum (Edea, Cameroun) was studied for up to the F7 hybrid generation and the biological characteristics of the hybrid were compared with those of each of the parental species. Using the total cercarial production/100 exposed snails/5 weeks value (TCP) as an index the hybrid miracidial infectivity to Bulinus forskalii (Kinshasa, Zaire), the host snail for S. intercalatum, remained comparable to that of S. intercalatum for up to at least the F5 generation and the TCP values for the hybrid/B. wrighti combination remained for up to the F7 generation intermediate between those of the parental species in B. wrighti. The hybrid also retained the infectivity for up to at least the F5 generation to B. globosus (Mazeras, Kenya), the host snail for S. haematobium, but the TCP values for the hybrid/B. globosus combination remained consistently lower than that of the S. haematobium/B. globosus combination. The hybrid cercarial infectivity to hamsters was for up to the F7 generation comparable to that of both parental species and the egg production capacity/worm pair/day of production of the F1 hybrid generation exceeded in both hamsters and mice that of both parental species. However, the egg production capacity subsequently decreased with that of the F3 to F6 generations in hamsters and with that of the F2 and F5 generations in mice being comparable to that of S. intercalatum. The pattern of distribution of eggs in tissue of hamsters of the F1 and F2 generations resembled that of S. haematobium and S. intercalatum, respectively, but the distributional pattern of the F3 to F6 generations deviated markedly from that of both the parental species and the preceding hybrid generations. The hybrid cercarial infectivity to mice and the pattern of egg distribution corresponded to that of S. intercalatum. The egg morphology of the P1 generation corresponded to that of S. intercalatum while that of the F1, F2 and F3 hybrid generations exhibited great polymorphism with a range of shapes through those of the parental species but with most eggs being intermediate in shape. However, the eggs of the F4 to F7 hybrid generations exhibited less polymorphism and resembled those of S. bovis in both size and shape.
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Mutani A, Christensen NO, Frandsen F. Studies on the relationship between Schistosoma and their intermediate hosts. V. The genus Bulinus and Schistosoma bovis from Iringa, Tanzania. Z Parasitenkd 1983; 69:483-7. [PMID: 6624195 DOI: 10.1007/bf00927704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The relationship between an isolate of Schistosoma bovis from Iringa, Tanzania, and various species of the host snail genus Bulinus from East Africa was studied using the total cercarial production per 100 exposed snails over a period of 4 weeks following patency as an index of the compatibility. All populations of Bulinus forskalii and B. africanus tested exhibited a high level of susceptibility while the populations of B. truncatus and B. globosus tested were either refractory or of low to moderately low susceptibility. All populations of B. abyssinicus, B. canescens, B. nasutus and B. tropicus tested were refractory. It is suggested that B. africanus is the most important host snail for S. bovis in East Africa, that B. forskalii at least locally may contribute significantly to the transmission and that B. truncatus and B. globosus only play a limited role in the transmission.
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Christensen NO, Mutani A, Frandsen F. A review of the biology and transmission ecology of African bovine species of the genus Schistosoma. Z Parasitenkd 1983; 69:551-70. [PMID: 6356670 DOI: 10.1007/bf00926667] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The present paper reviews the information available concerning the biology and transmission ecology of the African bovine species Schistosoma bovis, S. mattheei, S. margrebowiei and S. leiperi. Criteria for species identification (egg morphology, intermediate host spectra, definitive host-parasite relationships, etc.) are listed and the geographical distribution of the four species and factors determining the relative occurrence within their overall distributional ranges are described. S bovis and S. mattheei occur north and south of 10 degrees S, respectively, and S. margrebowiei occurs mainly, and S. leiperi only, in southern central Africa. Definitive host-related factors (susceptibility, water contact pattern, ect.) providing the background for being a primary definitive host and the primary definitive host spectra for the four schistosome species are described. The primary definitive host spectrum for S. margrebowiei and S. leiperi comprise lechwe, puku and waterbuck, for S. mattheei lechwe, puku, waterbuck plus cattle, and for S. bovis cattle and possibly also some of the listed antelope species. In addition, wild bovines and cattle may provide a reservoir of S. mattheei and S. margrebowiei in humans, but wild bovines and domestic stock play no major role in the transmission of other human species of schistosomes. The intermediate snail host spectra of S. mattheei and S. leiperi only comprise members of the Bulinus africanus species complex; S. bovis is transmitted by members of the B. truncatus, B. africanus and B. forskalii species groups, and S. margrebowiei is transmitted by members of the B. forskalii species group and possibly also by members of the B. tropicus and B. truncatus species groups. Factors determining the transmission ecology of the four schistosome species, and thereby the epidemiology of bovine schistosomiasis, are discussed. Influential factors comprise environmental conditions mediated via the effect of these on the size of the snail host population and on the rate of the intramolluscan development, behavioural patterns of the definitive host population and the course of the infection in the definitive host as related to aspects of susceptibility and level of endemicity. The epidemiological pattern (prevalence and intensity of infection, seasonality of transmission, etc.) is described and exemplified, and it is finally concluded that the increasing water conservation and changing methods of husbandry may result in bovine schistosomiasis becoming a major veterinary problem in Africa.
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Njau BC, Nyindo M, Mutani A. The interaction between the immune response of rabbits to heterologous antigens and a primary infestation with Rhipicephalus evertsi evertsi. Vet Res Commun 1990; 14:113-22. [PMID: 2345952 DOI: 10.1007/bf00346551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Rhipicephalus evertsi evertsi feeding on hosts inoculated with sheep red blood cells (SRBC) and bovine serum albumin (BSA) suppressed the primary antibody response to the two antigens. In addition, while the ticks paralysed most hosts in the studies, fatality associated with this toxicosis occurred only in rabbits which had received SRBC, either alone or with BSA. Only those hosts inoculated with BSA developed any resistance against the ticks, manifested by a slight reduction of engorged weights and development of anti-tick antibodies. These results suggest that R. e. evertsi infestation induces a degree of reduced host immune responsiveness to heterologous antigens.
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Affiliation(s)
- B C Njau
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
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