Geographical distribution, disease association and diversity of Klebsiella pneumoniae K/L and O antigens in India: roadmap for vaccine development.

Klebsiella pneumoniae poses a significant healthcare challenge due to its multidrug resistance and diverse serotype landscape. This study aimed to explore the serotype diversity of 1072 K. pneumoniae and its association with geographical distribution, disease severity and antimicrobial/virulence patterns in India. Whole-genome sequencing was performed on the Illumina platform, and genomic analysis was carried out using the Kleborate tool. The analysis revealed a total of 78 different KL types, among which KL64 (n=274/1072, 26 %), KL51 (n=249/1072, 24 %), and KL2 (n=88/1072, 8 %) were the most prevalent. In contrast, only 13 distinct O types were identified, with O1/O2v1 (n=471/1072, 44 %), O1/O2v2 (n=353/1072, 33 %), and OL101 (n=66/1072, 6 %) being the predominant serotypes. The study identified 114 different sequence types (STs) with varying serotypes, with ST231 being the most predominant. O serotypes were strongly linked with STs, with O1/O2v1 predominantly associated with ST231. Simpson's diversity index and Fisher's exact test revealed higher serotype diversity in the north and east regions, along with intriguing associations between specific serotypes and resistance profiles. No significant association between KL or O types and disease severity was observed. Furthermore, we found the specific association of virulence factors yersiniabactin and aerobactin (P<0.05) with KL types but no association with O antigen types (P>0.05). Conventionally described hypervirulent clones (i.e. KL1 and KL2) in India lacked typical virulent markers (i.e. aerobactin), contrasting with other regional serotypes (KL51). The cumulative distribution of KL and O serotypes suggests that future vaccines may have to include either ~20 KL or four O types to cover >85 % of the carbapenemase-producing Indian K. pneumoniae population. The results highlight the necessity for comprehensive strategies to manage the diverse landscape of K. pneumoniae strains across different regions in India. Understanding regional serotype dynamics is pivotal for targeted surveillance, interventions, and tailored vaccine strategies to tackle the diverse landscape of K. pneumoniae infections across India. This article contains data hosted by Microreact.

Circulation of Third-Generation Cephalosporin Resistant Salmonella Typhi in Mumbai, India.

We report the persistent circulation of third-generation cephalosporin resistant Salmonella Typhi in Mumbai, linked to the acquisition and maintenance of a previously characterized IncX3 plasmid carrying the ESBL gene blaSHV-12 and the fluoroquinolone resistance gene qnrB7 in the genetic context of a triple mutant also associated with fluoroquinolone resistance.

Comparative study of Smear Microscopy, Rapid Slide Culture, and Lowenstein - Jensen culture in cases of pulmonary tuberculosis in a tertiary care hospital.

BACKGROUND: Tuberculosis (TB), a dreadful disease known to mankind continues to be a problem in a developing country like India. The incidence of people getting infected with TB is on the rise due to compounding factors like coinfection with the human immunodefiency virus and multidrug-resistant strains. There is a definitive need for early diagnosis and treatment of TB to curb transmission of the infection. Direct smear microscopy, though cheap and rapid, lacks sensitivity. Isolation of Mycobacterium tuberculosis in culture requires a long time, because of which there is a need for a rapid method which has good sensitivity and specificity for the detection of M. tuberculosis. The present study was undertaken to determine the test which diagnoses TB rapidly and to compare the sensitivity of smear microscopy, concentration method, rapid slide culture, and Lowenstein - Jensen (LJ) culture. MATERIALS AND METHODS: Sputum samples of 200 patients were subjected to direct smear and concentration by modified Petroff's method. The concentrated sputum was also taken for slide culture using human blood medium and inoculated on LJ media. RESULTS: LJ culture was positive in 47 (23.5%) cases, of which three were nontubercular mycobacteria. Using LJ culture as the standard method, the sensitivity of direct smear, concentration method, and rapid slide culture method was 68, 83, and 89%, respectively, and specificity was 100% in all the three tests. CONCLUSION: Rapid slide culture showed good sensitivity which was comparable to and next in efficacy to LJ culture and this technique can be adopted in the Revised National Tuberculosis Control Program (RNTCP) as it is a rapid, cheap, sensitive, and specific method.