Indian Journal of Medical Microbiology最新文献

Introduction

Biapenem has been recently approved by the Drug Controller General of India for the treatment of complicated urinary tract infections (cUTI). However, there are no assessment studies that evaluate the in-vitro activity of biapenem against contemporary ESBL-producing Indian Enterobacterales isolates. To determine the activity of biapenem against contemporary ESBLs and/or OXA-1/ampC producing Enterobacterales and Pseudomonas aeruginosa isolates.

Methodology

Isolates were tested for susceptibility to biapenem and its comparators using the broth microdilution method. Presence of ESBLs (SHV, TEM, CTX-M) genes, OXA-1, and ampC genes (ACC, ACT, DHA, CIT/CMY, FOX) using multiplex PCR.

Results

Against ESBL with OXA-1 and/or ampC-producing E. coli, ESBL-K. pneumoniae, and cephalosporin-resistant P. aeruginosa, biapenem showed in-vitro activity similar to that of meropenem. Overall, a biapenem disc concentration of 10 μg provided no error rates for testing E. coli, K. pneumoniae, and P. aeruginosa isolates.

Conclusion

It is more accurate to test biapenem at a 10 μg disc concentration and apply more stringent disc diffusion breakpoints for interpretation.

Aeromonas species can cause a wide range of clinical infections. Several reports of drug resistance among the Aeromonas species have been reported, but our observations have differed. Here we present the changing susceptibility pattern of antibiotics for Aeromonas species over 14 years (January 2010–February 2024) at a tertiary care hospital in South India.

Background

PfK13 protein mutations are associated with the emergence of artemisinin resistance in Plasmodium falciparum. PfK13 protein is essential for mediating ubiquitination and controlling the PI3K/AKT pathway. Mutant PfK13 variations can interfere with substrate binding, especially with PfPI3K, which raises PfPI3K levels.

Methods

DUET, DynaMut2, mCSM, iStable 2.0, I-Mutant 2.0, and MuPro were utilized to study the protein stability and protein-substrate binding was studied using HADDOCK 2.4 docking algorithm between Wild-type and mutant PfK13 with the helical and catalytic domain of PfPI3K.

Results

i-Stable server analysis predicted that seven, out of the nine mutations associated with artemisinin resistance (F446I, Y493H, R539T, I543T, P553L, R561H, C580Y) reduced the protein stability. HADDOCK scores of the catalytic domain underscores the significant impact of the reported mutations on the binding affinity of the PfK13 protein. Further validation through the MM_GBSA technique, the binding free energy (DDG) between the wild-type and the mutant PfK13 protein analysis revealed a loss of interactions resulting from mutations in PfK13.

Conclusion

The study finding suggest that mutations in the PfK13 cause destabilization in the protein structure and affects the binding of PfPI3K. Although the findings remain preliminary and require further validation, it provides the basis for further research considering the importance of the interaction of PfK13 and PfPI3K to overcome the impact of artemisinin resistance.

Leptospirosis, an underdiagnosed zoonotic disease in India, was studied retrospectively in Madhya Pradesh, Central India. Between 2018 and 2019, 2617 samples from patients with hepatitis-related symptoms were collected. Of these, 518 tested negative for hepatitis and other tropical viral diseases under the VRDL project were analyzed for leptospira IgM using ELISA. 68 (13.12%) were positive for leptospirosis. Common symptoms included fever (97.45%) and jaundice (42.27%), with renal involvement in 30.88% of cases. Higher incidence was observed in the 31–60 age group, especially during monsoon and post-monsoon seasons. The study highlights the need for increased clinician awareness and inclusion of leptospirosis in screening panels to differentiate tropical illnesses in India.

Purpose

The study aims to compare random-access NeuMoDx values with artus qPCR values to validate the accuracy of NeuMoDx as an alternative to qPCR and provide an equation to convert copies/ml to IU/ml measurements.

Methods

A total of 95 samples, including 61 transplant patient samples (n = 23 urine, n = 38 plasma) as the study group, 28 BKPyV-free samples as the control group, and six quality control samples, were included. One-Way ANOVA, Pearson correlation, Bland-Altman, Passing-Bablok, Deming regression analyses were used for statistical evaluation.

Results

Of 95 samples, 46 (48 %) were positive with NeuMoDx, while 40 (42 %) were positive with artus qPCR. Both techniques were statistically similar (p > 0.05). Deming correlation analysis (r = 0.9590), Passing Bablok and Bland Altman analyses demonstrated a strong correlation between NeuMoDx and artus values. The equation that provides the conversion between NeuMoDx and artus qPCR values was NeuMoDx= (1.12965 x artus qPCR) – 0.55016. BKPyV infections remain a concern for transplant patients globally, and effective new diagnostic methods are required.

Conclusions

Consistency between the results of NeuMoDx and qPCR confirms that NeuMoDx may be a valuable alternative for detecting BKPyV to prevent viral propagation. Our findings may allow converting copy/ml results to IU/ml for diagnosing and monitoring BKPyV infections in transplant patients.

Pulmonary cryptococcosis is a fungal infection caused by Cryptococcus species, with Cryptococcus neoformans being the most common agent, affecting the lungs. While it commonly occurs in immunocompromised individuals, such as those with HIV/AIDS or undergoing immunosuppressive therapy, its presentation in patients with chronic kidney disease (CKD) is relatively rare. However, it should be considered in the differential diagnosis of respiratory infections in patients with CKD, particularly in the context of immunosuppression.

Purpose

Surgical site infection (SSI) is one of the frequent healthcare associated infections linked with significant morbidity, prolonged hospitalization, and death. SSI can be reduced by implementation of customized care bundle components as per standard guidelines. Hence this study was undertaken with the objective to implement care bundle in patients undergoing elective gastrointestinal surgeries and assess their impact on SSI rate.

Methods

The study was an interventional study conducted in the department of surgical gastroenterology for 8 months. Sample size was calculated to be 196 and only elective surgeries are included. CDC NHSN 2023 guidelines are used for surveillance of SSI and global guidelines for prevention of SSI was used for preparation of list of pre-operative, intraoperative and post-operative care bundle components and were implemented before the start of the study.

Results

Overall SSI rate and compliance to SSI care bundle in this study are 13.8% and 28.6%, respectively. When compared with the baseline SSI rate of 19.4%, there is reduction of 28.9% in SSI rate after the implementation of care bundle. Escherichia coli (54.2%) is the most commonly isolated organism. Care bundle non-compliant surgeries are associated with 2.3 times (relative risk-2.3) increased risk of SSI. There is fluctuating trend in compliance of care bundle and SSI rates across months.

Conclusion

This study shows the importance of implementation of set of care bundle for prevention of SSI which can be customized and adapted for reducing SSI.

Small colony variants (SCVs) in Klebsiella pneumoniae are rare and understudied. We report an SCV of Klebsiella pneumoniae isolated from the urine of a prostate cancer patient undergoing prolonged radiotherapy. The strain was non-lactose fermenting, non-mucoid, slow-growing, multi-drug resistant, and showed atypical biochemical reactions and biofilm formation. On whole genome sequencing, it showed low-level virulence, sequence type 231 and gene CTX-M-15. Three major porins OmpK35, OmpK36 and OmpK37 were found. SCVs pose challenges like difficulties in identification, altered metabolism, and increased biofilm formation, which contribute to persistent infections. Radiotherapy and chemotherapy may have led to the formation of the SCV phenotype.