Muhammad Luqman Sohail

Pathological alterations in respiratory system during co-infection with low pathogenic avian influenza virus (H9N2) and Escherichia coli in broiler chickens

Abstract Introduction: Despite the advancements in the field, there is a lack of data when it comes to co-infections in poultry. Therefore, this study was designed to address this issue. Material and Methods: Broiler birds were experimentally infected with E. coli (O78) and low pathogenic avian influenza (LPAI) strain, alone or in combination. The experimental groups were negative control. Results: The infected birds showed most severe clinical signs in E. coli+LPAI group along with a significant decrease in weight and enhanced macroscopic and microscopic pathological lesions. The survival rate was 60%, 84%, and 100% in birds inoculated with E. coli+LPAI, E. coli, and LPAI virus alone, respectively. The results showed that experimental co-infection with E. coli and H9N2 strain of LPAI virus increased the severity of clinical signs, mortality rate, and gross lesions. The HI titre against LPAI virus infection in the co-infected group was significantly higher than the HI titre of LPAI group, which may indicate that E. coli may promote propagation of H9N2 LPAI virus by alteration of immune response. Conclusion: The present study revealed that co-infection with E. coli and H9N2 LPAI virus caused more serious synergistic pathogenic effects and indicates the role of both pathogens as complicating factors in poultry infections.

Incidence and Drug Resistance of Zoonotic Mycobacterium bovis Infection in Peshawar, Pakistan

Prevalence of zoonotic Mycobacterium bovis (bTB) disease in human population is underreported from the North of Pakistan. Here, we report on the proportion of human bTB disease among the overall TB patients, drug resistance pattern of bTB isolates, and knowledge, attitude, and practices (KAP)-based analysis of bTB disease. For this purpose, sputum samples from a total of 300 clinically diagnosed TB patients and 100 randomly selected school children suspected of pulmonary TB were processed by culture as well as polymerase chain reaction (PCR) for isolation, identification, and confirmation of Mycobacterium tuberculosis (mTB) and bTB species. Isolates of bTB were processed for drug susceptibility tests. Data on KAP regarding TB were obtained on a pretested questionnaire. Sputum-based PCR results indicated that 288/300 (96%) were confirmed as mTB, while 12/300 (4%) were found as bTB diseases. Interestingly, none of the school child was declared positive for either mTB or bTB. Notably, 274/300 (91.3%) positively cultured samples were identified as mTB, 13/300 (4.3%) as bTB, while 5/300 (1.7%) as mixed containing both. Importantly, except one, all of the bTB isolates were found resistant to pyrazinamide. Surprisingly, most of the bTB isolates (~70%) were found resistant to a broad range of first- and second-line anti-TB drugs. SplitsTree and recombination analysis indicated no evidence of intergenic recombination. Finally, residence, occupation, presence of animals at home, and sleeping alongside animals were found significantly associated with occurrence of bTB disease. To the best of our knowledge, we report for the first time on the high (4%) burden of bTB disease in human TB patients in Peshawar, Pakistan.

Host immune responses and vaccination against avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is one of the most economically damaging diseases affecting the poultry industry. This group of extra-intestinal E. coli causes a variety of clinical conditions including air-sacculitis and cellulitis. The economic impact of APEC is mainly due to mortality, slower growth rates and carcass downgrading. In commercial broiler operations, APEC infections are controlled indirectly by vaccination against other respiratory diseases and minimising stress conditions, and directly by administration of antimicrobial agents to suppress symptoms in infected flocks. Several studies have demonstrated that the most common virulence factors studied in APEC are rarely present in the same isolate, showing that APEC strains constitute a heterogeneous group. Different isolates may harbour different associations of virulence factors, each able to induce colibacillosis. Despite its economical relevance, the pathogenesis of colibacillosis is poorly understood. The O antigen, a component of the surface lipopolysaccharide, has been identified as a promising vaccine target. With the availability of a novel bioconjugation technology it is expected that multivalent O antigen conjugate vaccines can be produced on an industrial scale. Despite the potential for developing an efficacious vaccine to combat this economically important poultry disease, several obstacles hinder such efforts. These include cost, vaccine delivery method and timing of vaccination. The present discusses current knowledge on APEC virulence, host response to infection and various attempts to develop an effective vaccine

Molecular characterisation of Leptospira strains in Pakistan

Abstract Introduction: Leptospirosis affects a wide range of mammals, humans, and even a few poikilothermic animal species. In Pakistan, serological studies of equine leptospirosis have reported a prevalence of over 40%, but no study has ever been conducted towards molecular detection of Leptospira in horses. Material and Methods: Blood samples from 128 horses were screened using ELISA and 41 positive samples were examined for the presence of leptospiral DNA using specific primers for 16S rRNA gene. Results: Out of 41 tested samples, 20 samples were found to be PCR-positive, revealing a fragment of 306 bp after gel electrophoresis. Sequencing and phylogenetic analysis of positive samples revealed circulation of pathogenic Leptospira spp. in Pakistani horses. No evidence of circulation of intermediate species was found in this study. Conclusion: This study reports the first molecular evidence of equine leptospirosis in Pakistan and lays ground for further research in this area. It also confirms the efficiency of 16S rRNA for the diagnosis of equine leptospirosis.