Sheep pox, goat pox, and lumpy skin diseases are economically significant and contagious viral diseases of sheep, goats and cattle, respectively, caused by the genus Capripoxvirus (CaPV) of the family Poxviridae. Currently, CaPV infection of small ruminants (sheep and goats) has been distributed widely and are prevalent in Central Africa, the Middle East, Europe and Asia. This disease poses challenges to food production and distribution, affecting rural livelihoods in most African countries, including Ethiopia. Transmission occurs mainly by direct or indirect contact with infected animals. They cause high morbidity (75-100% in endemic areas) and mortality (10-85%). Additionally, the mortality rate can approach 100% in susceptible animals. Diagnosis largely relies on clinical symptoms, confirmed by laboratory testing using real-time PCR, electron microscopy, virus isolation, serology and histology. Control and eradication of sheep pox virus (SPPV), goat pox virus (GTPV), and lumpy skin disease (LSDV) depend on timely recognition of disease eruption, vector control, and movement restriction. To date, attenuated vaccines originating from KSGPV O-180 strains are effective and widely used in Ethiopia to control CaPV throughout the country. This vaccine strain is clinically safe to control CaPV in small ruminants but not in cattle which may be associated with insufficient vaccination coverage and the production of low-quality vaccines.

No abstract

Background Bovine Respiratory Disease (BRD) is a multifactorial and economically important illness of cattle. The current study was designed to characterize the major bacterial pathogens associated with BRD and determine the antibiotic susceptibility patterns of isolates. Samples were collected from 400 pneumonic cases of cattle. Results Laboratory assay revealed isolation of 376 (94.0%) bacterial pathogens. The most prevalent bacterial pathogens recovered were Mannheimia haemolytica (M. haemolytica) followed by Pasteurella multocida (P. multocida), Histophilus somni (H. somni), and Bibersteinia trehalosi (B. trehalosi) from 191 (50.80%), 81 (21.54%), 56 (14.89%), and 48 (12.77%) samples, respectively. M. haemolytica strains were confirmed using multiplex PCR assay through the amplification of PHSSA (~ 325 bp) and Rpt2 (~ 1022 bp) genes. Capsular typing of P. multocida revealed amplification of serogroup A (hyaD-hyaC) gene (~ 1044 bp) and serogroup D (dcbF) gene (~ 657 bp). B. trehalosi isolates displayed amplification of the sodA gene (~ 144 bp). Besides, serotyping of M. haemolytica showed the distribution of serotype A:1 (82.20%), A:2 (10.47%), and A:6 (7.33%). Whereas, biotyping of P. multocida revealed a higher prevalence of biotype A:3 (83.95%), then A:1 (8.64%), A:2 (4.94%), and A:12 (2.47%). The majority of the retrieved isolates showed remarkable susceptibility to enrofloxacin, ciprofloxacin, sulfamethoxazole-trimethoprim, florfenicol, and ceftiofur (100%). Besides, varying degree of antimicrobial resistance was observed against streptomycin, gentamicin, penicillin-G, and ampicillin. Conclusions The current findings confirmed that M. haemolytica (A:1) strain is the most common bacterial pathogen identified from BRD cases in the study areas of Ethiopia. Hence, continuous outbreak monitoring and evaluation of antibiotics susceptibility patterns of bacterial pathogens associated with BRD are indispensable to reduce the impact of BRD in the study areas. Further investigation of bacterial pathogens and genotypic analysis of pathogens from a wider area of the country is essential to design a cost-efficient control strategy.

BackgroundPasteurellaceae families are usually considered opportunistic pathogens which inhabit normal flora on the mucosal membranes of the upper respiratory and the lower genital tracts of mammals and birds. The majority of P. multocida, M. hemolytica, and B. trehalosi isolates are opportunistic animal pathogens and cause disease only under certain conditions. Some of the target genes are shared by isolates found in the same or different genuses. The alpha / beta hydrolase kmt1 genes part of OMP and SLP are shared by all P.multocida species and FbpA is common gene for both P.multocida and M. hemolytica isolates. Other virulence related genes are used for genotyping of P.multocida, M.hemolytica and B.trehalosi isolates. The objective of the current research was focused on the detection and genotyping of different target genes that can be found in the isolates of P. multocida, M. hemolytica, and B. trehalosi using various PCR primers. The distributions of virulence-associated genes were assessed in the isolates of the three genera.Materials and methodsA total of eight isolates from P. multocida, M. hemolytica, and B. trehalosi isolated from clinical cases of cattle and sheep and stored at the Bacteriology laboratory of NVI were used as source of samples for the present study. DNeasy® Blood & Tissue Kit (Qiagen, Germany) was used for the extraction of DNA from bacterial isolates. Different primers were used for genotyping of P. multocida, P.hemolytica and B.trehalosi isolates.ResultsP.multocida was detected using species-specific kmt1 primer with an amplicon product of 460bp. Four serogroups of P.multocida (A, B, D, &E) were detected using serotype-specific primers with amplification products of 1044bp, 760bp, 657bp, and 511bp respectively. PCR was conducted to HS causing P.multocida type B and detected 620 bp amplicons. SLP genes were detected in all P.multocida serotypes with an amplification product size 1400-1553bp. In addition to that, the four P. multocida serotypes were found to be positive for BRD-PmSLP with an amplification product of 460bp but using recombinant HS-SLP primers resulted in the double band at 460 bp and 541bp for serotypes A and D. However, HS causing type B& E serotypes were detected with an amplified product of 541bp. TbpA2 has been detected with an amplicon size of approximately 750 bp for types (A and D) and 1300bp for type B using TbpA-F2/Rev primers. All of the P.multocida serotypes (A, B, D&E) and M. hemolytica (A: 1) were strongly positive for the iron acquisition FbpA gene with amplification bands at 500bp and 1000bp, respectively. A multiplex PCR assay was carried out for detection of M. haemolytica A: 1 using PHSSA and Rpt2 primers with amplification products of 327pb and 1022 bp respectively. The three isolates of B. trehalosi were identified using BtsodA primers with the result of 144bp amplicon size.ConclusionFrom this work, we understood that P.multocida and M. haemolytica shared genetic materials like iron binding proteins (FbpA) and some of the target genes (kmt1 and SLP) were commonly found in all isolates of P. multocida. However, TbpA2 was found to be in most but not in all Pasteurella isolates. We also observed that PHSSA and Rpt2 genes were exclusively found in M. hemolytica isolates whereas Bt-sodA was prominent in all B. trehalosi isolates (T3, T4&T15).