Molecular characteristics of Clostridium difficile isolates from human and animals in the North Eastern region of India.

A total of 1034 samples were collected from different sources and C. difficile was isolated from 18 (9.04%) of 199 human, 9 (4.89%) of 184 cattle, 29 (12.44%) of 233 pig, and from 23 (13.94%) of 165 poultry samples. Variations were observed on the rate of isolation according to age and clinical conditions (diarrhoea). None of the samples from cow, sheep, goat, local chicken, and wild animals yielded any C. difficile. Out of those isolates, 8, 2, 19 and 6 isolates from human, cattle, pig and poultry, respectively were toxigenic. The toxigenic isolates carried both tcdA, and tcdB (A+B+) and most of the human and the pig isolates were also positive for binary toxin genes (cdtA and cdtB). The A+B+ isolates belonged to three different toxinotypes (0, VI and XXXIII). Human and pig A+B+ isolates belonged to three (045, 126 and ACD 019) and four (046, 087, 126 and ACD 011) different ribotypes, respectively and the ribotypes of two cattle isolates were 014 and ACD 010. Six A+B+ avian isolates belonged to six different ribotypes (014, 087, SLO 134, SLO 160, ACD 012, ACD 014). The non-toxigenic isolates from human, cattle, pig and poultry were grouped into 7, 4, 4 and 7 different ribotypes, respectively. PFGE analysis could not differentiate similar ribotypes/toxinotypes of toxigenic isolates. All the toxigenic isolates showed cytopathic effect on Vero and Hela cell monolayers at 1:100 dilutions of cell-free culture supernatants within 18-20 h of inoculation.

Isolation and characterization of Shiga toxigenic Escherichia coli of animal and bird origin by multiplex polymerase chain reaction.

AIM: The purpose of this study was to determine the virulence genes and serotype of Shiga toxin producing Escherichia coli (STEC) strains isolated from animals and birds. MATERIALS AND METHODS: A total of 226 different samples viz., fecal, intestinal content, rectal swab and heart blood were collected from different clinically affected/healthy animals and birds and were streaked on McConkeys' lactose agar and eosin methylene blue agar for isolation of E. coli, confirmed by staining characteristics and biochemical tests. By polymerase chain reaction (PCR) all the E. coli isolates were screened for certain virulence genes, viz., Shiga toxin 1 (stx1), stx2 and eae and enterohemolytic (Ehly) phenotype was observed in washed sheep blood agar plate. All the isolated E. coli strains were forwarded to the National Salmonella and Escherichia Centre, Central Research Institute, Kasauli (Himachal Pradesh) for serotyping. RESULTS: Out of 226 samples 138 yielded E. coli. All the isolates were screened for molecular detection of different virulent genes, viz. stx1, stx2 and eae, based on which 36 (26.08%) were identified as STEC. Among those STEC isolates, 15 (41.67%), 14 (38.89%), 1 (2.78%) exhibited eae, stx2, stx1 alone, respectively, whereas 4 (11.11%) and 2 (5.56%) carried both stx1 and stx2, stx2 and eae, respectively. Among the STEC isolates 22 were belonged to 15 different sero-groups, viz., O2, O20, O22, O25, O43, O60, O69, O90, O91, O95, O106, O118, O130, O162 and O170 and others were untypable. Ehly phenotype was observed in 10 (27.78%) the STEC isolates. CONCLUSION: The present study concluded that STEC could be isolated from both clinically affected as well as healthy animals and birds. Regular monitoring of more samples from animal and bird origin is important to identify natural reservoir of STEC to prevent zoonotic infection.

Isolation and characterization of Clostridium difficile from pet dogs in Assam, India.

One hundred and seventeen faecal samples from pet dogs (pup = 21 and adult = 96) brought for treatment to a veterinary clinic were examined for Clostridium difficile. A total of 16 (13.67%) samples were positive. Nine (56.25%) isolates were obtained from 17 adult dogs undergoing antibiotic treatment and this was significantly higher (p < 0.01) as compared to isolates from dogs without antibiotic treatment. Ten isolates (62.5%) were toxigenic (all toxinotype 0) and six were non-toxigenic. None of the isolates were positive for binary toxin genes. PCR ribotyping revealed three different ribotypes (012, 014 and 046) among A(+)B(+) isolates and five different ribotypes (010, SLO 131, and ACD 001 to ACD 003) among A(-)B(-) isolates. The PFGE analysis of toxigenic isolates revealed three different pulsotypes corresponding to the PCR ribotypes.