Retrospective and longitudinal study of salmonellosis in captive wildlife in Trinidad

Morbidity and mortality of captive wildlife at the Emperor Valley Zoo, Trinidad from 1993 to 1996 were analysed to determine involvement of Salmonella spp. A 6 mo longitudinal study was conducted to determine the frequency of isolation of Salmonella spp. from apparently healthy, sick and dead wild mammals, birds, and reptiles. The antibiograms of Salmonella isolates were determined using the disc diffusion method. Fecal samples randomly selected from animal enclosures and cloacal swabs of snakes were cultured for Salmonella spp. following enrichment in tetrathionate and selenite cystine broths. For the 1993-96 period, Salmonella spp. was implicated in 17 (12%) of 141 sick or dead animals and the predominant serotype was S. typhimurium. During the 6 mo prospective study in a mean animal population of 1,186, there were 20 (2%) and 14 (1%) animals that were sick and died respectively; Salmonella spp. was implicated in only one mortality. Overall, of 1,012 samples from apparently healthy wildlife cultured, 66 (7%) yielded 24 serotypes of Salmonella. The predominant serotype were S. seigburg (16 isolates), S. gaminara (6 isolates), and S. thompson (6 isolates). None of the samples yielded S. typhimurium. The frequency of isolation of Salmonella spp. in reptiles (14%) was significantly higher than found in either mammals (7%) or birds (3%). Sixty-five (99%) of 66 Salmonella spp. isolates exhibited resistance to one or more of the nine antimicrobial agents tested. Resistance was high to cephalothin (92%), moderate to streptomycin (35%) and tetracycline (29%), but significantly low to gentamicin (2%), chloramphenicol (0%), and sulphamethoxazole/trimethoprim (0%). The prevalence of asymptomatic infections by Salmonella spp. in zoo animals was high and the very high prevalence of antimicrobial resistance could be a problem when treating salmonellosis.

Salmonella serotypes, Salmonella typhi phage types, and anti-microbial resistance at the University Hospital of the West Indies, Jamaica

Bacteriologically proved cases of salmonellosis presenting at the University Hospital have increased nearly threefold since 1957. The most striking change has been a considerable increase in the incidence of Salmonella heidelberg and salmonella derby in the last 5 years, probably resulting from hospital acquired infection. About 80 cases of typhoid fever are reported each year in Jamaica. There has been little change in the prevalence of different phage types of Salmonella typhi since 1961. Paratyphoid fever is rare. Standardized antimicrobial disk-sensitivity testing was performed on selected surviving salmonella strains since 1964. S.typhi has remained fully sensitive to all the agents tested except streptomycin. Other salmonellas, however, have shown a significant increase in antimicrobial resistance since 1970. Most of this increase was due to multiple resistance in S.heidelberg and S.derby, and the survived andissemination of these strains in the hospital environment may be related to antibiotic usage (AU)

Antimicrobial resistance in organisms isolated at the University Hospital of the West Indies during 1975

The results of standardized disc-sensitivity testing for common bacterial pathogens isolated from clinical specimens at the University Hospital of the West Indies during 1975 are reported. Antibiotic resistance and multiple resistance is now common, multiple resistance occurring in 54 percent of Gram negative isolates and 37 percent of Gram positives. Seventy-nine per cent isolates of Staphylococcus aureus were resistant to penicillin but only 7 percent were resistant to methicilin. Sixty-three per cent of both Gram negative and Gram positive isolates showed resistance to ampicillin but most organisms remained sensitive to cotrimoxazole. Although S. typhi remained fully sensitive to the commonly-used antibiotics, other Salmonellae showed resistance to both ampicillin and chloraphenicol in 52 percent of isolates. Isolates of Shigellae, however, showed surprisingly little antibiotic resistance. Cotrimoxazole remains an effective agent against most of the multiple-resistant organisms except Pseudomonas aeruginosa. It is suggested that the restriction of the use of chloramphenicol might preserve its effectiveness for serious infections, such as typhoid fever (AU)

Multiresistance Salmonella Ohio infections at the University Hospital of the West Indies

During 1982-83 there was a substantial increase in the number of S. ohio infections at the University Hospital of the West Indies, which coincided with the appearance of strains resistance to chloramphenicol, cotrimoxazole, ampicillin, neomycin and carbenicillin. Multiresistance strains of S. ohio accounted for 19.3 percent of all salmonella isolates during this period and all of 40 strains tested were able to transfer resistance determinants to E. coli K12 J 53-2. S. ohio was cultured from stool (60), blood (5), wounds and abscesses (4) and postmortem material (2). Eighty-six percent of S. ohio infections occurred in children of 3 years old or less. There was a high incidence of gastroenteritis in malnourished children, a 14 percent incidence of localizing infections and a 7 percent incidence of septicaemia. Two infants with severe gastroenteritis and bronchopneumonia died. There were a number of unusual infections including two cases of septicaemia in children receiving chloramphenicol for Haemophilus infleunzae meningitis, a scrotal abscess secondary to extravastion of urine and infected scabies in a child with marasmic kwashiorkor.(Summary)