Aims: The activation of cellular and humoral immunity depends upon nature of antigens. Complex proteins like bacterial outer membrane proteins (OMP) usually successfully activate both humoral and cellular immunity. Whereas antigens like bacterial lipopolysaccharides (LPS) usually elicit T-independent immunity i.e. humoral immunity without the activation of cellular immune wing. The present study was under taken to evaluate the comparative immunologic behavior of both the important molecules (bacterial lipopolysaccharide and outer membrane proteins) of Pasteurella multocida alone and in combination in bovine calves in field conditions. Methodology and results: Pasteurella multocida was isolated, purified and identified from an outbreak by mean of culture and biochemical methods. The pathogenicity of the confirmed isolates was done in rabbits (Oryctolagus cuniculus) on the principles of Koch’s postulates. Alum based vaccine against P. multocida was prepared and antibody titer against Outer membrane protein (OMP) and lipopolysaccharides (LPS) were determined by complement fixation test (CFT). The results showed that the antibody titer against OMP and LPS in whole culture vaccine is significantly higher than the respective tested vaccines. These results concluded that OMP no doubt is an active T-dependent immunogenic molecule but its immunogenicity increases many times when combined with LPS in whole culture vaccine. Conclusion, significance and impact of study: Lipopolysaccharides (LPS) in combination with outer membrane proteins (OMP) synergistically boost the humoral immune response in vaccinated animal.

Aims: The study was carried out firstly, to evaluate the prevalence of extended spectrum beta lactamase (ESBL), multidrug resistant Klebsiella pneumoniae isolates from Punjab, Pakistan and secondly, to characterize the genotypes of their beta lactamase producing enzymes and optimization of PCR based method for rapid and authentic detection of antibiotic resistant gene. Methodology and results: Two hundred of K. pneumonia strains were isolated from different clinical samples. Blood and MacConkey Agar were used to isolate and identify bacterial microorganisms while Muller Hinton Agar was used to evaluate the antimicrobial susceptibility against different antibiotics as per CLSI 2012 guidelines. ESBL producing bacteria were screened by double disk synergy /combination disk test. PCR was optimized and performed for resistant gene (CTX-M). The results showed that most of the isolates were resistant to multiple antibiotic including cephalosporin, aztreonam, sulphamethoxazole/trimethoprim, ciprofloxacin, doxycyclin and were sensitive to imipenam and amikacin. Frequency of CTX-M gene in ESBL producing K. pneumoniae was 94%. Conclusion, significance and impact of study: Based on the finding of this study it is suggested that prevalence of CTX-M gene (95%) is very high among ESBL producing isolates. Therefore, PCR based method may help clinicians for rapid detection and treatment of patients by choosing right medication against the resistant bacteria as early as possible.