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Aims:  The present study focused on cloning and expression of chiA gene from a highly chitinolytic local isolate of Serratia marcescens in an anti‐Coleopteran Bacillus thuringiensis and comparison of the characteristics of the native and recombinant ChiAs. Methods and Results:  chiA gene from Ser. marcescens was cloned, sequenced and compared with the previously cloned chiA genes. chiA gene was PCR cloned and expressed in anti‐Coleopteran B. thuringiensis strain 3023 as verified by Western blot analysis. Specific ChiA activity of the recombinant B. thuringiensis (strain 3023‐SCHI) reached its highest level at 21st hour of growth (16·93 U mg−1), which was 5·2‐ and 1·3‐fold higher than that of its parental strain and Ser. marcescens, respectively. Temperature and pH effects on native and recombinant ChiAs were next determined. The recombinant plasmid was quite stable over 240 generations. Conclusions:  Serratia marcescens ChiA was heterologously expressed in an anti‐Coleopteran B. thuringiensis at levels even higher than that produced by the source organism. Significance and Impact of the Study:  Bacillus thuringiensis 3023‐SCHI co‐expressing anti‐Coleopteran Cry3Aa protein and Ser. marcescens chitinase offers a viable alternative to the use of chitinolytic microbes/enzymes in combination with entamopathogenic bacteria for an increased potency because of synergistic interaction between them.

Bordetella pertussis is the causative agent of whooping cough (pertussis) which is a worldwide vaccine preventable acute respiratory illness that predominantly involves infants. The reactogenicity of whole-cell (Pw) vaccines and the difficulty of their consistent production have led to the development of acellular pertussis (Pa) vaccines. However, despite high vaccination coverage using either Pw or Pa and introduction of adolescent and adult vaccines with reduced antigen content, there are still reports about the circulation of the microorganism in populations, morbidity in infants and increasing incidence of pertussis among adolescent and adults who transmit the infection to yet unimmunized infants. Waning vaccine-induced immunity and antigenic divergence in circulating strains seem to be the major problems accounting for resurgence of pertussis. Considering the need for new vaccination strategies, improvement of current Pa vaccines by including new virulence factors would probably be the most rationale strategy. Recent advances in B. pertussis proteomics, subproteomics and immunoproteomics greatly aided in identifying novel antigens of the pathogen. Future studies involving quantitative transcriptomic and proteomic profiling of host-B. pertussis interactions, studying gene expression in vivo and reverse vaccinology will also be very promising approaches and tools to develop pertussis vaccines inducing long term immunity.