Helminthic infestation in children of Kupwara district: a prospective study

The present study deals with the investigation of the frequency of intestinal helminth parasites in children of Kupwara, Kashmir, India. Three hundred and twelve children in the age group of 4-15 years were examined for different intestinal helminths in three schools located in rural areas. Two hundred and twenty two of 312 (71.15%) tested positive for various intestinal helminths. The various helminth parasites included Ascaris lumbricoides , Trichuris trichiura , Enterobius vermicularis and Taenia saginata . By far, the highest frequency of 69.23% (216/312) was noted for Ascaris lumbricoides followed by Trichuris trichiura 30.76% (96/312), Enterobius vermicularis 7.69% (24/312) and Taenia saginata 7.69% (24/312). Single infection was found in 33.65% (105/312) and mixed infection was seen in 37.5% (117/312) children. This study emphasizes the need for improved environmental conditions, i.e., clean water supplies, enhanced sanitation and chemotherapy of school-age children in rural areas.

Variants of eae and stx genes of atypical enteropathogenic Escherichia coli and non-O157 Shiga toxin-producing Escherichia coli from calves

AIMS

To determine the subtypes of stx and eae genes of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) from calves and to ascertain the typical and atypical nature of EPEC.

METHODS AND RESULTS

One hundred and eighty-seven faecal samples from 134 diarrhoeic and 53 healthy calves were investigated for the presence of stx, eae and ehxA virulence genes by polymerase chain reaction and enzyme-linked immunosorbent assay. Subtype analysis of stx(1) exhibited stx(1c) in 13 (31.70%) isolates, while that of stx(2) revealed stx(2c) in eight (24.24%) and stx(2d) in two (6.06%) isolates. Subtyping of eae gene showed the presence of eae-beta, eae-eta and eae-zeta in two, three and four isolates respectively. None of the E. coli isolates possessed stx(2e), stx(2f), eae-alpha, eae-delta, eae-epsilon and eae-xi. All EPEC isolates were atypical.

CONCLUSIONS

stx(1), stx(1c), stx(2), stx(2c), stx(2d), eae-beta, eae-eta and eae-zeta subtypes are prevalent in STEC and EPEC isolates in India.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first subtype analysis of stx(2) and eae genes of animal E. coli isolates in India and emphasizes the need to investigate their transmission to humans.

Isolation and characterization of Dichelobacter nodosus from ovine and caprine footrot in Kashmir, India

Footrot is a highly contagious and economically important disease of sheep and goats, caused by Dichelobacter nodosus, a slow growing anaerobic Gram-negative rod. The current Australian antigenic classification system, based on variation in the fimbriae, classifies D. nodosus into at least 10 serogroups (A-I and M) and 18 serotypes. This investigation was intended to determine the serological diversity of D. nodosus in this region of Kashmir, India. Exudates of footrot lesions were collected from 24 naturally infected sheep and 42 goats located in the Kashmir valley. Of these 66 samples, 24 yielded evidence of D. nodosus by PCR using 16SrDNA specific primers. Multiplex PCR using serogroup specific primers revealed the presence of serogroup B in all the samples except two, which showed the presence of serogroup E D. nodosus. This study also documents the isolation of D. nodosus and detection of serogroup E for the first time in India.

Molecular epidemiology of ovine herpesvirus type 2 infection in Kashmir, India

The aims of this investigation were to determine the prevalence of ovine herpesvirus type 2 (OvHV-2) (the causative agent of malignant catarrhal fever) infection in cattle, the carrier status of sheep and goats, and to define the pattern of acquisition of OvHV-2 in lambs under natural flock conditions in Kashmir, India. None of the buffy coat samples from 21 lambs contained OvHV-2 DNA sequences up to 28 days after birth, only one lamb had sequences of OvHV-2 DNA as early as 29 days after birth, and they were detected in the other 20 lambs when they were between 43 and 94 days of age. Sequences of OvHV-2 DNA were detected in buffy coat samples from 28 (85 per cent) of 33 adult sheep and in 16 (61 per cent) of 26 samples from adult goats by hemi-nested PCR. Seventeen (31 per cent) of 55 cattle with malignant catarrhal fever-like clinical signs had sequences of OvHV-2 DNA in their blood, and nine of the 17 died, all of them during the months of April to November, between November 2002 and March 2004. No clinical cases of sheep-associated malignant catarrhal fever was recorded during the months of December to March. The overall prevalence of OvHV-2 infection in the cattle in the region was estimated to be less than 1 per cent.

Shiga toxin-producing Escherichia coli and enteropathogenic Escherichia coli in healthy goats in India: occurrence and virulence properties

AIMS

To describe the occurrence and virulence gene pattern of shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) in healthy goats of Jammu and Kashmir, India.

METHODS AND RESULTS

A total of 220 E. coli strains belonging to 60 different 'O' serogroups was isolated from 206 local (nonmigratory) and 69 migratory goats. All the 220 strains were screened for the presence of stx(1), stx(2), eaeA and hlyA genes. Twenty-eight E. coli (75.6%) strains from local and nine (24.3%) strains from migratory goats belonging to 18 different serogroups showed at least presence of one virulence gene studied. Twenty-eight strains (16.47%) (belonging to 13 different serogroups) from local goats carried stx(1) gene alone or in combination with stx(2) gene, while as only one strain (2%) from migratory goats possessed stx(2) gene alone. Interestingly in the present study none of the STEC strains carried eaeA gene. Similarly, none of the strains from local goats possessed eaeA and none of the migratory goats possessed stx(1) gene. Eight strains (16%) (belonging to four different serogroups) from migratory goats carried eaeA gene. Twenty-five (14.7%) and seven (14%) strains from local and migratory goats harboured hlyA gene respectively.

CONCLUSIONS

Healthy goats of Jammu and Kashmir state serve as a reservoir of STEC and EPEC. Further studies in this direction are needed to work out whether or not they are transmitted to humans in this part of world.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first report of isolation of STEC and EPEC strains from healthy goats in Jammu and Kashmir State of India, which could be a source of infection to humans.

Current understanding of the aetiology and laboratory diagnosis of footrot

Footrot is a highly contagious disease of the feet of ruminants caused by the synergistic action of certain bacterial species of which Dichelobacter nodosus (D. nodosus) is the main transmitting agent. The infection is specific to sheep and goats, although it has also been reported in cattle, horses, pigs, deer and mouflon. The antigenic diversity of D. nodosus is due to variations in the DNA sequence of its fimbrial subunit gene (fimA) and provides the basis for classification of the organism into at least 10 major serogroups (A-I and M), the distribution of which varies with different geographical locations. Host immune response to vaccination is serogroup specific. There are three different clinical forms of disease caused by virulent, intermediate and benign strains of D. nodosus, respectively. In order to facilitate rapid and reliable clinical diagnosis, virulence determination, strain differentiation and serogroup identification for effective control measures, immunological tests, DNA probes and PCR based techniques have been introduced. This review summarises the current understanding of the mechanisms of antigenic diversity of D. nodosus as well as advances made in its strain differentiation and diagnosis.

Determination of bovine rotavirus G genotypes in Kashmir, India

Rotavirus ribonucleic acid (RNA) was extracted from ten faecal samples of diarrhoeic calves positive for group A rotavirus by enzyme-linked immunosorbent assay (ELISA). A portion of the extracted RNA was run in polyacrylamide gel to determine the presence of rotaviral RNA and the rest subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) to generate the near full length VP7 gene. Only six samples yielded the desired product. The amplified products were subjected to G-typing by PCR using a cocktail of G6, G8 and G10 typing primers. All of the six samples were characterised as G10 and none of the samples revealed mixed infection by twin G types. Four samples, despite possessing sufficient rotavirus particles as revealed by ELISA and polyacrylamide gel electrophoresis, did not yield any amplified product on RT-PCR. This could be due to non-specific inhibitors of the PCR reaction, present in the faecal samples, being carried through the extraction procedures.

Investigation of shiga toxin-producing Escherichia coli in avian species in India

AIMS

To investigate the presence or absence of shiga toxin-producing Escherichia coli (STEC) in avian species in India.

METHODS AND RESULTS

Faecal samples originating from 500 chicken and 25 free flying pigeons were screened for the presence of E. coli. A total of 426 (chicken, 401; pigeons, 25) E. coli strains were isolated. Of 426 E. coli strains, 387 were grouped into 77 serogroups, while 70 and 59 strains were untypable and rough, respectively. All isolates were subjected to multiplex polymerase chain reaction (m-PCR) for the detection of stx(1), stx(2), eaeA, hlyA and saa genes. None of the E. coli strains studied showed the presence of stx(1), stx(2) or their variants and saa genes. Overall 11 (2.74%) and seven (1.74%) strains from chickens possessed eaeA and hlyA genes, respectively, while as only six (1.49%) strains from chickens possessed both eaeA and hlyA genes. O9, O8, O60 and O25 serogroups were most predominant of which there were 24 (5.63%), 23 (5.39%), 23 (5.39%) and 20 (4.69%) strains, respectively. None of the isolates from pigeons showed the presence of any of the virulence genes studied.

CONCLUSIONS

STEC are absent in chickens and pigeons. However, further studies are required in this direction to confirm or contradict our findings. E. coli strains originating from birds are carrying a low percentage eaeA or hlyA genes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study is the first attempt to investigate STEC in chickens and free flying pigeons in India. The chickens and pigeons cannot be considered as important carrier of STEC in India.

Molecular detection and characterization of Dichelobacter nodosus in ovine footrot in India

Dichelobacter nodosus was detected in three clinical cases of ovine footrot in Kashmir, India. The detection was done by PCR in three clinical specimens directly, without isolating the organism, using species-specific 16S rDNA primers. Positive results were indicated by amplification of a 783 bp product. All the three samples were subjected to serogrouping by multiplex PCR using group (A-I) specific primers. All the three samples revealed the presence of serogroup B of D. nodosus by yielding a single band of 283 bps.

Isolation and characterization of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) from calves and lambs with diarrhoea in India

AIMS

To determine the prevalence and molecular characteristics of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) in calves and lambs with diarrhoea in India.

METHODS AND RESULTS

Faecal samples originating from 391 calves and 101 lambs which had diarrhoea were screened for presence of E. coli. A total number of 309 (249 bovine and 60 ovine) E. coli strains were isolated. A total of 113 bovine and 15 ovine strains were subjected to multiplex polymerase chain reaction (m-PCR) for detection of stx1, stx2, eaeA and EHEC hlyA genes. STEC and EPEC belonging to different serogpoups were detected in 9.73% of calves studied. Six per cent and 26.66% of lambs studied were carrying STEC and EPEC, respectively. Majority of the STEC serogroups isolated in this study did not belong to those which have been identified earlier to be associated mainly with diarrhoea and enteritis in cattle and sheep outside India. The most frequent serogroup among bovine and ovine EPEC was O26 (40%). One of the most important STEC serogroup O157, known for certain life-threatening infections in humans, was isolated from both bovine and ovine faecal samples.

CONCLUSIONS

A high percentage of STEC and EPEC belonging to different serogroups are prevalent in calves and lambs with diarrhoea in India and could be the cause of disease in them.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study reports, for the first time, the isolation and characterization of STEC and EPEC serogroups associated with diarrhoea in calves and lambs in India. Many STEC and EPEC strains belonged to serogoups known for certain life-threatening diseases in humans.

Detection of a mammalian-like group A rotavirus in diarrhoeic chicken

The present investigation describes detection of a mammalian-like electropherogroup A rotavirus in chicken with diarrhoea. This also records the first detection of a rotavirus in an avian species from India. During the investigation 75 diarrhoeic faecal samples collected from adult chicken were screened for the presence of group A rotavirus antigen by sandwich ELISA. All three samples positive for rotavirus antigen revealed 11 bands of RNA in polyacrylamide gel electrophoresis (PAGE). In contrast to avian group A rotavirus, segment 5 was found to migrate closer to 6 as is the case with mammalian group A rotaviruses. Segments 7, 8 and 9 were found to migrate as a tight triplet, which is characteristic of group A rotavirus.

Molecular characterization of an Indian isolate of Japanese encephalitis virus that shows an extended lag phase during growth

The biological properties of an Indian isolate (GP78) of Japanese encephalitis virus (JEV) were characterized in tissue-cultured cells and mice and these were compared with the JaOArS982 strain from Japan. The GP78 strain had a markedly extended lag phase during its growth in porcine stable kidney (PS) cells. There were no obvious defects in the penetration of GP78 into PS cells. However, viral RNA and protein synthesis were significantly delayed in GP78-infected PS cells. Fusion-from-within assays carried out in C6/36 cells indicated that GP78 was less fusogenic than the JaOArS982 strain of JEV. Moreover, maximum fusion in GP78-infected cells occurred at pH 5.5, whereas JaOArS982-infected cells showed maximum fusion at pH 6.0. These results suggested that there may be a lesion in the virus-cell fusion process. The GP78 strain also showed delayed growth in brains of 1-week-old BALB/c mice. Although JEV GP78 was as virulent as the JaOArS982 strain in these mice, the appearance of clinical symptoms of JEV infection was delayed by a day in mice infected with the GP78 strain and these animals showed an increased average survival time. Comparison of the nucleotide sequences of the GP78 and the JaOArS982 strains of JEV identified a number of amino acid substitutions in structural proteins. Of these, a Thr --> Met substitution at residue 76 of the envelope protein is predicted to be causally associated with the altered biology of the GP78 strain during growth.