Ante-mortem and Post-mortem Diagnosis Modalities and Phylogenetic Analysis of Rabies Virus in Domestic and Wild Animals of Gujarat, India.

In the present study, total of 32 ante-mortem (AM) samples (saliva = 18 and corneal smears = 14) from six animal species (cattle = 5; camel = 1; goat = 1; horse = 1; buffalo = 4; dog = 6) and 28 post-mortem (PM) samples of domestic (cattle = 6; camel = 1; goat = 1; buffalo = 5; dog = 7) and wild animals (lion = 4, mongoose = 2; bear = 1; leopard = 1) were examined for rabies diagnosis in Gujarat, India. Direct fluorescent antibody test (dFAT) and reverse transcriptase polymerase chain reaction (RT-PCR) were applied on AM samples, whereas along with dFAT and RT-PCR, histopathological examination, immunohistochemistry (IHC) and real time PCR (qPCR) were used for PM diagnosis. Nucleotide sequencing of full nucleoprotein (N) and glycoprotein (G) genes were carried out upon representative amplicons. In AM examination, 7/18 saliva and 5/14 corneal impressions samples were found positive in dFAT and 8/18 saliva samples were found positive in RT-PCR. In PM examination, 14/28 samples showed positive results in dFAT and IHC with unusual large fluorescent foci in two samples. In histopathology, 11/28 samples showed appreciable lesion and Negri bodies were visible in 6 samples, only. Out of 23 brain samples examined. 12 samples were found positive in N gene RT-PCR and qPCR, and 10 samples in G gene RT-PCR. Phylogenetic analysis of N gene revealed that test isolates (except sample ID: lion-1; lion, Gir) form a close group with sequence ID, KM099393.1 (Mongoose, Hyderabad) and KF660246.1 (Water Buffalo, Hyderabad) which was far from some south Indian and Sri Lankan isolates but similar to Indian isolates from rest of India and neighboring countries. In G gene analysis, the test isolates form a close group with sequence ID, KP019943.1. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01126-0.

Genotyping of Indian antigenic, vaccine, and field Brucella spp. using multilocus sequence typing.

INTRODUCTION: Brucellosis is one of the most important zoonotic diseases that affects multiple livestock species and causes great economic losses. The highly conserved genomes of Brucella, with > 90% homology among species, makes it important to study the genetic diversity circulating in the country. METHODOLOGY: A total of 26 Brucella spp. (4 reference strains and 22 field isolates) and 1 B. melitensis draft genome sequence from India (B. melitensis Bm IND1) were included for sequence typing. The field isolates were identified by biochemical tests and confirmed by both conventional and quantitative polymerase chain reaction (qPCR) targeting bcsp 31Brucella genus-specific marker. Brucella speciation and biotyping was done by Bruce ladder, probe qPCR, and AMOS PCRs, respectively, and genotyping was done by multilocus sequence typing (MLST). RESULTS: The MLST typing of 27 Brucella spp. revealed five distinct sequence types (STs); the B. abortus S99 reference strain and 21 B. abortus field isolates belonged to ST1. On the other hand, the vaccine strain B. abortus S19 was genotyped as ST5. Similarly, B. melitensis 16M reference strain and one B. melitensis field isolate were grouped into ST7. Another B. melitensis field isolate belonged to ST8 (draft genome sequence from India), and only B. suis 1330 reference strain was found to be ST14. CONCLUSION: The sequences revealed genetic similarity of the Indian strains to the global reference and field strains. The study highlights the usefulness of MLST for typing of field isolates and validation of reference strains used for diagnosis and vaccination against brucellosis.

The use of pathological and histopathological techniques in the diagnosis of peste des petits ruminants in India.

The authors report on an outbreak of peste des petits ruminants (PPR) among sheep and goats in the Province of Gujarat, India. Clinical signs observed during outbreaks were typical of PPR. Predominant signs were severe diarrhoea, dyspnoea, mucopurulent discharge from the eyes and nose, erosive rhinitis, necrotic ulcers in the mouth, on the dental pad, tongue, upper and lower lips, fever and depression. Common post-mortem findings included congestion, red hepatisation, raised patches of emphysema in the lungs, haemorrhages and froth exudates in the trachea, severe enteritis and streaks of haemorrhages in the intestine, enlargement and petechial haemorrhages in the spleen and oedema and inflammatory lesions in the mesenteric lymph nodes. Spectacular histopathological changes were observed in the lungs, intestine, spleen, mesenteric lymph nodes, liver and kidneys. Clinical, gross and histopathological lesions and haematological changes were suggestive of PPR, which was further confirmed by detection of PPR viral antigen in clinical samples, as well as post-mortem tissues using the sandwich enzyme-linked immunosorbent assay (s-ELISA).