Evolutionary Transition of Hypervirulent Klebsiella pneumoniae to multidrug-resistant Hypervirulent Klebsiella pneumoniae: Indian experience.

An emerging pathotype of Klebsiella pneumoniae, initially identified in Southeast Asian countries, has now spread to multiple countries, including India. These convergent strains, carrying both resistance and virulence determinants, are classified as multidrug-resistant Hypervirulent Klebsiella pneumoniae (MDR-HvKp). Since the initial reports, there has been a concerning surge in infections caused by this pathotype globally. In this context, we aim to shed light on the evolutionary changes that have taken place in this relatively novel pathotype. Understanding these changes is crucial for devising diagnosis and targeted intervention strategies to mitigate the spread of MDR-HvKp infections.

Activity of novel lactone ketolide nafithromycin against multicentric invasive and non-invasive pneumococcal isolates collected in India.

BACKGROUND: India is among the nations reporting substantial healthcare burden linked to pneumococcal infections. Nafithromycin is a novel lactone ketolide antibiotic, which recently entered Phase 3 development in India for the indication of community-acquired bacterial pneumonia (CABP). OBJECTIVES: To assess the in vitro activity of nafithromycin against serotyped invasive and non-invasive Streptococcus pneumoniae isolates, collected from nine medical centres across India. METHODS: A total of 534 isolates of S. pneumoniae were collected during 2015-20 and serotyped as per CDC protocol. A subset of erythromycin-non-susceptible S. pneumoniae (n = 200) was screened for the presence of erm(B) and mef(A/E) genes. A subset of MDR isolates (n = 54) were also subjected to MLST. The MICs of antibiotics were determined by the reference agar-dilution method (CLSI). Susceptibilities of the comparators were interpreted as per CLSI criteria. RESULTS: Fifty-nine distinct serotypes were identified among the 534 isolates. Among erythromycin-non-susceptible isolates, erm(B) and mef(A/E) genes were found in 49% and 59% strains respectively, while MLST showed clonal diversity. Azithromycin (67.6% non-susceptible) and clindamycin (31.8% non-susceptible) showed limited activity. Penicillin (for non-meningitis) or quinolone non-susceptibility was low (<11% and <6%, respectively). Nafithromycin showed potent activity with MIC50 and MIC90 of 0.015-0.03 and 0.06 mg/L, respectively, regardless of the macrolide resistance mechanisms. CONCLUSIONS: Indian pneumococcal isolates show poor susceptibilities to macrolides, in concordance with the global trend. Nafithromycin overcomes erm as well as mef-mediated macrolide resistance mechanisms expressed individually or concurrently in S. pneumoniae. This study supports continued clinical development of nafithromycin for pneumococcal infections including CABP.

Draft genome sequence of carbapenem-resistant Elizabethkingia anophelis strain BP8467 clinical isolate from India.

OBJECTIVES: Elizabethkingia spp. are Gram-negative, glucose-non-fermenting bacilli that are ubiquitous in natural environments such as soil, plant and water sources. Besides environmental sources, the bacterium can be found in hospital environments, particularly medical equipment and reagents. Here we report the draft genome sequence of an Elizabethkingia anophelis isolate from a blood culture. METHODS: Genomic DNA of E. anophelis strain BP8467 was sequenced on an Ion Torrent PGM platform and the reads were assembled de novo using SPAdes v.5.0.0. The draft genome was annotated using the Prokaryotic Genome Annotation Pipeline (PGAP) v.4.9. Genetic determinants of antimicrobial resistance as well as virulence factors were identified using computational tools. RESULTS: The assembled draft genome is 3859105bp in length with a G+C content of 35.62% distributed in 30 contigs. Presence of the blaBlaB and blaGOB-4 genes associated with resistance to carbapenems was identified. In addition, genes conferring resistance to other ß-lactams (blaCME-1), aminoglycosides [ant(6)-I] and chloramphenicol (catB) were also detected. Antimicrobial susceptibility testing showed that the isolate was susceptible to levofloxacin, trimethoprim/sulfamethoxazole, tetracycline and rifampicin. CONCLUSION: The presence of a multidrug-resistant isolate harbouring diverse antimicrobial resistance genes along with numerous virulence factors suggests the risk associated with Elizabethkingia spp. infections. This genome analysis provides insights into the antimicrobial resistance and pathogenicity mechanisms of multidrug-resistant E. anophelis that can help in the management of Elizabethkingia spp. infections in the future.

Prevalence of High and Low Level Mupirocin Resistance among Staphylococcal Isolates from Skin Infection in a Tertiary Care Hospital.

BACKGROUND: Mupirocin has been used for the treatment of skin infections and for the eradication of the nasal carriage of Methicillin -resistant Staphylococcus aureus (MRSA). The increased use of this antibiotic has been accompanied by its resistance, resulting in treatment failures. OBJECTIVE: This study was aimed at determining the prevalences of low and high level Mupirocin resistance among the clinical isolates of Staphylococcus species which were obtained from pyogenic infections. MATERIAL AND METHOD: Clinical samples such as wound swabs, tissues and pus which were submitted to the microbiology laboratory during a period of six months were screened for the growth of Staphylococcus species, which were identified as Staphylococcus aureus and Coagulase negative Staphylococcus species by the routine microbiological procedures. All the isolates were tested for their Mupirocin susceptibilities by using 5 and 200 µg discs and their resistance was confirmed from their Minimum Inhibitory Concentrations (MICs). RESULT: Out of 400 samples, 150 samples grew Staphylococcus species, of which 113 were Staphylococcus aureus and 37 were Coagulase negative Staphylococcus (CoNS). Only 5(3.3%) mupirocin resistant Staphylococcus species: three high level and two low level strains were detected. The MICs for the two low level and three high level Mupirocin resistant strains were 256 mg/L and ≥512mg/L each respectively. CONCLUSION: We conclude that the screening for mupirocin resistance, in terms of high-level and low-level resistance among the Staphylococcus species from patients with skin and soft tissue infections is warranted and that it is important for the clinicians in selecting the appropriate, empirical, topical, antimicrobial therapy. It also provides useful information about the prevalence of these resistant pathogens.