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Our study aimed to explore the genetic variation in the Toll-like receptor 4 (TLR4) gene and establish its association with somatic cell score (SCS) and milk production traits in four Indian camel breeds namely Bikaneri, Kachchhi, Jaisalmeri and Mewari. TLR4 gene fragment of 573 bp spanning 5’ UTR, exon-1 and partial intron-1 region was amplified and genotyped using the PCR-sequence based typing method. Only one SNP located at position C472T was identified. Genotyping revealed two alleles (C and T) and three genotypes: CC, CT and TT. The genotype frequencies for CC, CT and TT were 0.116, 0.326 and 0.558 and allele frequencies for C and T alleles were 0.279 and 0.721, respectively. Association study inferred that the effect of genotype on SCS, lactation yield (LY) and peak yield (PY) was non-significant however heterozygote (CT) genotypes recorded lower SCS and higher LY and PY. It can be concluded that the TLR4 gene possesses limited genetic variation, depicting polymorphism at a single locus in Indian camel breeds with a predominance of the TT genotype. The association study indicated that heterozygote animals possess better udder health and production performance, the statistical significance of which needs to be established using a large data set.

Toll-like receptors (TLRs) are an important family of receptors constituting the first line of defense system. Tolllike receptors play crucial roles in the innate immune system by recognizing pathogen-associated molecular patterns derived from various microbes. Present investigation was carried out to characterize the coding sequence of TLR2 gene in Indian dromedary camels. Blood was collected from five Bikaneri camels and genomic DNA was isolated. Eight pairs of overlapping primers were designed for amplification of TLR2 gene coding region. All the fragments were successfully amplified using Polymerase chain reaction (PCR). The PCR products were purified and subjected to Sanger’s sequencing. TLR2 gene fragment of 3213 bp consisting of 2287 bp of coding sequence of exon 2 and 926 bp of 3’untranslated region (UTR) was successfully amplified. The sequence generated was submitted to the NCBI with accession number MW557315.1. The encoded amino acids codes for 12 leucine rich repeats (LRR) (Accession no. UBN09134.1). At the nucleotide level, the Bikaneri camels’ TLR2 gene showed highest similarity with camelids (99.30 to 99.59%) followed by vicugna pacos (97.54%). The nucleotide sequence similarity was lowest with Homo sapiens (82.37%). The amino acid sequence based phylogenetic tree revealed close relationship between camelid species followed by pig (86.2%), whereas human, gorilla, horse and donkey were distantly placed on the tree.

Tuberculosis (TB) is a serious public health problem worldwide, especially in tropical developing countries. Nevertheless, reports on congenital TB in humans and animals are extremely rare. In this study, abortion was reported in an 8-year-old she-camel at the 9th month of gestation. The she-camel appeared healthy in clinical examination, had a good body condition score, normal appetite, and had no signs of respiratory disease and fever. The expelled placenta was dark red-colored, thickened, and edematous with multifocal to coalescing ecchymotic hemorrhages on the allantoic surface. The striking finding was multiple, white-yellow, solid nodular lesions in the fetal lung, the pleura, and the liver. On histopathology, typical granulomatous lesions were detected in the lung and the liver characterized by caseous necrosis surrounded by lymphocyte and macrophage infiltration and concentric layers of fibrosis. The Ziehl-Neelsen staining detected scarce acid-fast bacilli in lung and liver tissues. The DNA extracted from tubercular lesions from the lung and liver showed amplification of the IS6110 region of the Mycobacterium tuberculosis complex by PCR. The sequencing and phylogenetic analysis revealed a close association of these sequences with Mycobacterium tuberculosis. The she-camel was detected positive for a single intradermal tuberculin test performed 24 h after abortion. This is the first report on congenital TB caused by M. tuberculosis in a dromedary camel fetus with a possible vertical transmission.

Camelpox is a wide-spread infectious viral disease of camelids. An outbreak of camelpox was reported in 15 adult male dromedary camels aged between 10 to 16 years of an organized herd in winter season. The infected camels showed clinical signs of fever, anorexia, lachrymation, pendulous lips, excessive salivation and pock lesions on the skin of head, neck, mouth, lips, extremities, thigh, abdomen, scrotum and inguinal region. Mortalities were recorded in three infected camels after 10–12 days of infection and showed systemic pox lesions characterized by vesicles, papules, ulcerations and raised pock lesions in the mucous membranes of the mouth, tongue, tracheal mucosa, lung, abomasum and liver. Histopathology study revealed characteristic pox lesions with intracytoplasmic eosinophilic inclusion bodies in tongue. Lung showed lesion of interstitial pneumonia (n = 2) and bronchointerstitial pneumonia (n = 1). Liver showed infiltration of mononuclear cells around central veins and degenerative changes of hepatocytes. The abomasum and intestine showed ulcerations, marked capillary congestion and areas of lymphocyte infiltration in mucosa and submucosa. The presence of camelpox virus (CMLV) was confirmed in viral DNA isolated from formalin fixed paraffin embedded (FFPE) tissues of tongue, lung, abomasum, liver, heart and intestine of infected camels by C18L gene PCR. The sequencing of viral DNAs showed phylogenetic relatedness with other CMLV isolates from India and other countries. Thus, our study confirmed the rare severe form of systemic camelpox outbreak in adult male dromedary camels hence future attention should be given for studies on virulence, strain identification and molecular epidemiology of CMLV for planning of effective preventive and control strategies.