Otpornost na antimikrobne tvari, fenotipska obilježja i fagotipovi sojeva vrste B. abortus izdvojenih iz goveda i azijskih bivola (Bubalus bubalis) u Trinidadu.

Strains of Brucella abortus isolated from cattle and domestic water buffalo (Bubalus bubalis) in Trinidad and Tobago were characterized as to their phenotypic features, phage types and resistance to antimicrobial agents using standard methods. A total of 86 isolates were recovered from the lymph nodes of 14 apparently healthy seropositive cattle and 17 water buffalo, skin lesions of 9 water buffalo and aborted tissues of 16 water buffalo. In addition 2 vaccine strains, B. abortus strains 19 (S19) and RB51 (SRB51) were tested. All (100.0%) strains of B. abortus tested grew in the presence of penicillin G, i-erythritol and basic fuchsin but none (0.0%) grew in the presence of thionin blue. All 88 (100.0%) strains of B. abortus were susceptible to bacteriophages TB and BK2 but 84 (95.5%) were lysed by bacteriophage Wb. Of the 8 antimicrobial agents tested by the disc diffusion method, all 42 (100.0%) cattle and water buffalo carried resistant isolates and all 88 (100.0%) isolates of B. abortus exhibited resistance to one or more of the antimicrobial agents. All sources considered, resistance was high to azithromycin (100.0%), sulphamethoxazole/trimethoprim (98.9%) and moxifl oxacin (80.7%) and low to streptomycin (5.7%), tetracycline (1.1%) and doxycycline (1.1%). The differences in prevalence of resistance of B. abortus isolates to antimicrobial agents were statistically significant (P0.05; χ2). Resistance to antimicrobial agents used in the treatment of human brucellosis poses a public health hazard, but most of the strains had similar phenotypic characteristics and bacteriophage susceptibility patterns.Određivana su fenotipska obilježja, fagotipovi i otpornost na antimikrobna sredstva sojeva bakterije Brucella abortus izdvojenih iz goveda i azijskog bivola (Bubalus bubalis) u Trinidadu i Tobagu. Ukupno je 86 izolata bilo izdvojeno iz limfnih čvorova 14 klinički zdravih serološki pozitivnih goveda i 17 indijskih bivola, iz ozljeda kože devet bivola te tkiva pobačenih plodova 16 bivola. Analizirana su bila i dva cjepna soja bakterije B. abortus, soj 19 (S19) i RB51 (SRB51). Svi analizirani sojevi razmnožavali su se u prisutnosti penicilina G, i-eritritola i bazičnog fuksina, a nijedan se nije razmožavao u prisutnosti tioninskog modrila. Svih 88 sojeva bilo je osjetljivo na bakteriofage TB i BK2, a 84 (95,5%) bili su lizirani bakteriofagom Wb. Sva pretražena goveda i bivoli nosili su sojeve rezistentne na jednu ili više antimikrobnih tvari. Uzročnici su bili testirani na 8 antimikrobnih tvari disk-difuzijskim postupkom. Velika otpornost ustanovljena je na azitromicitestirani na 8 antimikrobnih tvari disk-difuzijskim postupkom. Velika otpornost ustanovljena je na azitromicin (100,0%), sulfametoksazol/trimetoprim (98,9%) i moksifloksacin (80,7%). Slaba otpornost bila je ustanovljena na streptomicin (5,7%), tetraciklin (1,1%) i doksiciklin (1,1%). Razlike u prevalenciji rezistencije izolata B. abortus na antimikrobne tvari bile su statistički značajne (P<0,05; χ2), ali su izolati iz goveda i bivola imali sličnu prevalenciju otpornosti (P<0,05; χ2). Otpornost na antimikrobne tvari rabljene za liječenje bruceloze u ljudi ima javnozdravstveno značenje. Većina izolata ima slična fenotipska obilježja i sličnu osjetljivort na bakteriofage

Frequency of Detection of Escherichia coli, Salmonella spp., and Campylobacter spp. in the Faeces of Wild Rats (Rattus spp.) in Trinidad and Tobago

The study was conducted to determine the frequency of isolation of Salmonella, Campylobacter and E. coli O157 in the faecal samples of rats trapped across the regional corporations in Trinidad and to assess their resistance to antimicrobial agents. A total of 204 rats were trapped for the detection of selected bacteria. Standard methods were used to isolate Salmonella, Campylobacter and E. coli O157. Characterization of E. coli was done on sorbitol MacConkey agar to determine non-sorbitol fermentation, blood agar to determine haemolytic and mucoid colonies and by using E. coli O157 antiserum to determine O157 strain. The disc diffusion method was used to determine resistance to nine antimicrobial agents. Of the 204 rats, 4 (2.0%), 7 (3.4%) and 171 (83.8%) were positive for Salmonella spp., Campylobacter spp. and E. coli, respectively. Of the 171 isolates of E. coli tested 0 (0.0%), 25 (14.6%) and 19 (11.1%) were haemolytic, mucoid and non-sorbitol fermenters, respectively. All isolates were negative for the O157 strain. The frequency of resistance to the 9 antimicrobial agents tested was 75% (3 of 4) for Salmonella, 85.7% (6 of 7) of Campylobacter spp. and 36.3% (62 of 171) for E. coli (P < .05; χ2)

Isolation of enteric pathogens from bats in Trinidad

Bats are one of the most widely distributed mammals in the world, and they are reservoirs or carriers of several zoonoses. Bats were trapped in 27 geographic locations across Trinidad and Tobago, and following euthanasia, gastrointestinal tracts were aseptically removed. Contents were subjected to bacteriologic analysis to detect Salmonella spp., Escherichia coli, and Campylobacter spp. Isolates of Salmonella were serotyped, and E. coli isolates were screened for O157 strains and antimicrobial sensitivity to eight antimicrobial agents; phenotypic characteristics also were determined. Of 377 tested bats, representing 12 species, four bats (1.1%) were positive for Samonella spp, 49 (13.0%) were positive for E. coli, and no bats were positive for E. coli O157 strain or Campylobacter spp. Isolated serotypes of Salmonella included Rubislaw and Molade, both from Noctilio leporinus, a fish-eating bat, Caracas recovered from Molossus major, and Salmonella Group I from Molossus ater, both insect-eating bats. Of the 49 isolates of E. coli tested, 40 (82%) exhibited resistance to one or more antimicrobial agents, and the prevalence of resistant strains was comparatively high to erythromycin (61%) and streptomycin (27%) but lower to gentamycin (0%) and sulphamethozaxole/trimethoprim (2%)

Serological Evidence of Exposure to Leptospira spp. in Veterinary Students and Other University Students in Trinidad and Tobago

The study compared the serological evidence of leptospirosis in 212 students in four schools (veterinary, dental, advanced nursing education and pharmacy) of the University of the West Indies (UWI), by testing for IgG immunoglobulins to Leptospira spp. using the enzyme-linked immunosorbent assay (ELISA) and the microscopic agglutination test (MAT). Overall, of 212 students tested by the ELISA, 12 (5.7%) and 31 (14.6%) were positive and borderline, respectively. Amongst the 113 veterinary students 11 (9.7%) and 19 (16.8%) were seropositive and borderline respectively compared with nonveterinary students with corresponding values of 1 (1.0%) and 12 (12.1%). The frequency of serological evidence of leptospirosis by the ELISA was statistically significantly (; ) higher in veterinary students, 26.5% (30 of 113) than in nonveterinary students, 13.1% (13 of 99). By the MAT, the seropositivity for leptospirosis was similar for veterinary students, 7.1% (8 of 113) and nonveterinary students, 7.1% (7 of 99). For veterinary students, the prevalent infecting serovar was Icterohaemorrhagiae Copenhageni while amongst nonveterinary students, the prevalent serovar was Australis Rachmati. Being a veterinary student was the only risk factor that was significantly associated with Leptospira infection indicating that veterinary students need to be cognizant and to practise preventive measures for leptospirosis

Prevalence and Characteristics of Enteric Pathogens Detected in Diarrhoeic and Non-Diarrhoeic Foals in Trinidad

The study determined the relative importance of Escherichia coli, E. coli O157, Salmonella spp., Clostridium spp., rotavirus, Cryptosporidium spp., and Strongyloides westeri in foal (diarrhoeic and non-diarrhoeic) available for sampling during the foaling season of 2010 and determined their sensitivity to antimicrobial agents. A cross-sectional study was conducted on 164 foals (9 diarrhoeic and 155 non-diarrhoeic) from 15 farms in Trinidad. Isolation and detection of enteric pathogens followed standard methods, and the antibiograms of E. coli and Salmonella spp. were determined using the disc diffusion method. All organisms investigated were detected except E. coli O157. A high prevalence of E. coli (85.0%), Cryptosporidium spp. (64.8%), Strongyloides westeri (35.7%) was seen, but the prevalence was comparatively low for Clostridium spp. (12.9%), Salmonella spp. (4.4%) and rotavirus (2.1%). Only Salmonella spp. was isolated at a statistically significantly (<0.05; 2) higher frequency from diarrhoeic (25.0%) than non-diarrhoeic (4.0%) foals. Amongst E. coli isolates, the frequency of resistance was higher in isolates from diarrhoeic compared with non-diarrhoeic foals but the difference was only statistically significant (<0.05; 2) for tetracycline. All isolates of Salmonella spp. were sensitive to streptomycin and sulphamethoxazole/trimethoprim, a finding that may have therapeutic significance

Virulence of Brucella abortus isolated from cattle and water buffalo

Brucellosis has been documented in domestic water buffalo (Bubalus bubalis) but published literature is limited despite the importance of this species in tropical agricultural systems. The objective of this study was to compare the virulence of Brucella abortus isolates recovered from cattle and water buffalo. Nineteen strains of B. abortus from cattle and domestic water buffalo in Trinidad were intraperitoneally inoculated into BALB/c mice. Spleens were cultured for B. abortus and histopathological severity scores were calculated based on lymphoid depletion, lymphoid necrosis, splenitis, and macrophage accumulation. A general linear model approach was used to estimate the effect of isolate source (cattle versus water buffalo) on virulence. Isolates of water buffalo origin were significantly less virulent in the mouse model based on recovered B. abortus from splenic tissues, spleen/weight ratio, and lymphoid necrosis but not overall histopathological severity scores. Further investigation of isolates recovered from water buffalo might provide the key to the development of procedures for brucellosis control in tropical environments.The authors are grateful to the Campus Research Funds Committee, St. Augustine Campus for funding the research project