Nadira Seepersadsingh

Some bacterial enteropathogens in wildlife and racing pigeons from Trinidad

Fecal and cloacal swabs or feces of wild mammalian, avian and reptilian species, either farmed or free-ranging, and of racing pigeons (Columba livia) kept in lofts were cultured for Salmonella spp., Campylobacter spp., and Yersinia spp. Of 291 free-ranging mammals tested, 6 (2%) and 1 (<1%) yielded positive cultures of Salmonella spp. and Campylobacter spp., respectively. Salmonella newport was the predominant serotype isolated and the opossum (Didelphis marsupialis insularis) had the significantly highest prevalence (29%) of Salmonella spp. infection compared to other species such as deer (Mazama americana trinitatis), lappe (Agouti paca), tattoo (Dasypus novemcinctus), agouti (Dasyprocta leporina), and wild hog (Tayassu tajacu). Among 14 species of farmed wildlife studied, 13 (7%) and 10 (5%) of 184 fecal or cloacal samples tested were positive for Salmonella spp. and Campylobacter spp., respectively. Salmonella javiana accounted for 50% of the Salmonella spp. isolates and C. jejuni represented 90% of the Campylobacter spp. cultured. Only 1 (1%) of 124 cloacal swabs of free-flying avian species yielded Salmonella spp. compared to 21(17%) samples positive for Campylobacter spp. Of 171 racing pigeons which originated from 8 fanciers, 8 (5%) yielded Salmonella spp. all of which were serotype typhimurium while only 1 (1%) was positive for Campylobacter spp. Seven (88%) of 8 Salmonella spp. isolates were recovered from one fancier. Yersinia spp. was not cultured from any of the above samples. Although the prevalences of Salmonella spp. and Campylobacter spp. in wildlife in Trinidad are low, the practice of wildlife farming and the increased consumption of meat from wildlife may increase the health risk to human consumers.

Microbial health risk posed by table eggs in Trinidad

A survey of the microbial quality of table eggs sold in Trinidad was conducted. For 23 poultry layer farms each visited twice approximately 1 month apart, 25 pooled eggs constituted a composite sample, for 14 shopping malls each visited twice approximately 1 month apart, six pooled eggs made a composite sample and for a total of 102 other retailers across the country each visited once over a 4-month period, six pooled eggs constituted a composite sample. Swabs of egg shells and egg content were tested for selected bacteria. Twenty-four (13.0%), 68 (37.0%), and two (1.1%) of a total of 184 composite eggs (shells, egg content or both) sampled were positive for Salmonella, Escherichia coli, and Campylobacter respectively. All 184 samples tested were negative for Listeria spp. Salmonella was recovered from seven (3.8%) egg shell samples only compared with 14 (7.6%) egg content samples only positive for the pathogen. Fifty-two (28.3%) egg shell samples and seven (3.8%) egg content samples were positive for E. coli. Both isolates of Campylobacter coli originated from egg contents. Of a total of 24 composite egg samples positive for Salmonella, eight different serotypes of Salmonella were isolated from a total of 24 Salmonella-positive composite eggs of which S. Enteritidis was the most prevalent, 58.3% (14/24). Salmonella Georgia was isolated for the first time in Trinidad. Failure to properly handle or heat table eggs sold in Trinidad poses a potential health hazard to consumers because of their poor microbial quality.

Prevalence of antimicrobial residues in table eggs in Trinidad.

The prevalence of antimicrobial residues in pooled table eggs from layer farms, shopping malls, and supermarkets in Trinidad was determined. A total of 23 layer farms and 14 shopping malls were sampled twice, 1 month apart, whereas 102 supermarkets were each sampled once. For each farm, 25 eggs were randomly collected and pooled to constitute a composite sample, whereas six eggs from each farm source available at sale outlets were randomly sampled from malls and supermarkets to constitute a composite sample. Questionnaires were administered at the farms to determine the occurrence of risk factors for contamination of antimicrobial residues in eggs and at sale outlets to determine storage conditions. The Charm II test was used to qualitatively detect antimicrobial residues (beta-lactams, macrolides, sulfonamides, and tetracyclines). Of 46 composite eggs tested from farms, 3 (6.5%) were contaminated with residues compared with 5 (16.1%) of 31 and 16 (15.0%) of 107 mall and supermarket eggs, respectively, but the difference was not statistically significant (P > 0.05). The residues detected were as follows: sulfonamides, 12 (6.5%) of 184; macrolides, 7 (3.8%) of 184; tetracycline, 5 (2.7%) of 184; and beta-lactam, 0 (0.0%) of 184. The difference was statistically significant (P < 0.05). The use of medicated feeds on farm, claim of adherence to the antimicrobial withdrawal period, and temperature of egg storage did not significantly (P > 0.05) affect the prevalence of residues in eggs. It was concluded that the presence of antimicrobial residues, particularly sulfonamides, in table eggs could be of public health significance to the consumer.

Achado de bactérias selecionadas em crianças de Trinidad com doença amigdaliana crônica

Faringoamigdalite na populacao pediatrica e largamente tratada com antibioticos. OBJETIVO: Estudar a microflora presente na superficie e no nucleo de amigdalas apos adenoamigdalectomia eletiva em criancas. METODO: Amigdalas de 102 criancas de Trinidad foram prospectivamente estudadas por meio de culturas e identificacoes bacteriologicas feitas a partir de amostras das superficies e nucleos de suas amigdalas entre 2005-2006. RESULTADOS: A partir de 360 amigdalas, foram isolados Streptococcus spp. (51,3%), Staphylococcus spp. (42,3%) e Gram-Negativos (6,4%). A identificacao de estafilococos e estreptococos tanto na superficie quanto no nucleo foi semelhante (p>0,05). Encontramos mais (p<0,001) Streptococcus spp. nas superficies (82,2%) do que nos nucleos (63,3%); a prevalencia de estreptococos alfa-hemoliticos foi maior (p<0,001) do que aquela de estreptococos beta-hemoliticos nas superficies (74,4% vs. 18,6%) do que nos nucleos (58,9% vs. 13,7%). Nao houve concordância entre superficies e nucleos com relacao a estreptococos (p<0,0004) e estreptococos alfa-hemoliticos (p<0,007). Estreptococos beta-hemoliticos foram mais identificados (p<0,05) em criancas dentre 6-16 anos do que naquelas entre 1-5 anos de idade (31% e 23,8% vs 12,5% e 8%). A prevalencia de S. pyogenes na superficie e no nucleo foi de (84,6% vs 70%) e (50,0% vs 25,0%) em criancas de maior faixa etaria e criancas mais novas, respectivamente. Klebsiella spp. (6,6%, 2,2%), Proteus (4,4%, 4,4%) e Pseudomonas (4,4 %, 1,1%) cresceram nas superficies e nucleos, respectivamente. CONCLUSAO: As superficies amigdalianas tinham mais estreptococos e estreptococos hemoliticos do que seus nucleos. Criancas mais velhas tiveram mais estreptococos beta-hemoliticos, e sao altamente colonizadoras de S. pyogenes. Sugerimos estudos que investiguem os mecanismos de aderencia estreptococica em criancas de Trinidad.

Selected bacterial recovery in Trinidadian children with chronic tonsillar disease.

UNLABELLED Pharyngotonsillitis in children is widely treated with antibiotics. AIM To examine tonsil surface and core microflora following elective adenotonsillectomy in children. METHODS Tonsils of 102 Trinidadian children were prospectively examined for surface and core bacteriological culture and identification between 2005-2006. RESULTS Tonsils (360) yielded 800 isolates of Streptococcus spp. (51.3%), Staphylococcus spp. (42.3%) and Gram-negative genera (6.4%). Surface and core recovery of staphylococci and streptococci were similar (p>0.05). More (p<0.001) surfaces (82.2%) than cores (63.3%) grew Streptococcus spp.; alpha-haemolytic Streptococcus prevalence was higher (p<0.001) than ss-haemolytic Streptococcus on surfaces (74.4% vs. 18.6%) than cores (58.9% vs. 13.7%). Surfaces and cores were not concordant for streptococci (p<0.0004) and alpha-haemolytic Streptococcus (p<0.007). Surface and core ss-haemolytic Streptococcus yield was higher (p<0.05) in 6-16 than 1-5 year olds (31% and 23.8% vs 12.5% and 8%). S. pyogenes surface and core prevalence was (84.6% vs 70%) and (50.0% vs 25.0%) in older and younger children respectively. Klebsiella spp. (6.6 %, 2.2%), Proteus (4.4%, 4.4%) and Pseudomonas (4.4 %, 1.1%) grew on surfaces and cores respectively. CONCLUSION Tonsil surfaces yield higher surface than core carriage for streptococci overall and for alpha haemolytic streptococci. Older children grow more beta-haemolytic streptococci and are high colonizers of S. pyogenes. Studies probing the mechanisms of streptococcal adhesions in Trinidadian children are suggested.