Indian Journal of Medical Microbiology最新文献

Background

& objective: The existence of visually identical cryptic Aspergillus species that can be distinguished only by molecular techniques is becoming more widely acknowledged. For the majority of antifungal drugs, these are known to exhibit a greater minimal inhibitory concentration in vitro. For the purpose of receiving the proper care, it is crucial to identify these species at right time. Our aim in this work is to identify and describe the Aspergillus species that are cryptic from all of the clinical samples.

Methods

Routine samples from inpatients and outpatients received in department of Microbiology, All India Institute of Medical Sciences, New Delhi, showing growth of Aspergillus species were included in this study. Phenotypic and Matrix Assisted Laser Desorption Ionisation - Time of Flight identified isolates were analysed for cryptic species, by PCR and ITS/ß – tubulin sequencing. In accordance with CLSI recommendations, antifungal susceptibility testing was conducted using micro broth dilution.

Results

Of the 94 isolates, 54 A. fumigatus, 34 A. flavus, 3 A. nidulans, 2 A. terreus, and 1 A. niger were morphologically identified. MALDI-TOF misidentified 2 A. nidulans isolates and 1 A, stellatus isolate. The ß – tubulin sequence analysis revealed that 2 isolates (2.08 %) were cryptic, one was A. stellatus and another one was A. tubingensis.

Purpose

The Centers for Disease Control and Prevention has classified methicillin-resistant S aureus (MRSA) as a serious public health threat. The escalating minimum inhibitory concentration (MIC) of standard anti-methicillin-resistant S aureus (MRSA) drugs within the susceptible range, known as "MIC creep," jeopardizes their effectiveness against MRSA infections, posing additional challenges in managing MRSA infections. This cross-sectional study was conducted in a tertiary care hospital in Central India to assess the susceptibility trends of clinical MRSA isolates against commonly used anti-MRSA drugs and to observe MIC creep, if any, over three years (2020–2022).

Methods

The study included 158 non-repetitive clinical MRSA isolates. The MICs of vancomycin, teicoplanin, and linezolid were determined in MRSA strains using agar dilution, while the MIC of daptomycin was performed by broth microdilution. MIC creep was assessed by calculating MIC50, MIC90, Modal MIC, G-mean MIC, and susceptible and resistant percentages for the fiscal years 2020, 2021, and 2022.

Results

Of the 158 MRSA isolates, none were resistant to vancomycin, teicoplanin, and daptomycin, but two showed resistance to linezolid (LRSA). However, fifteen isolates showed intermediate resistance to vancomycin (VISA), and five showed intermediate resistance to teicoplanin (TISA). MIC of these anti-MRSA drugs increased in 2021 and 2022 compared to 2020. G-mean MIC for vancomycin, teicoplanin, and linezolid in MRSA strains increased significantly over the study period, while daptomycin MIC remained relatively stable, with a slight increase in 2021 and 2022. There was a high resistance rate for clindamycin, doxycycline, and chloramphenicol among VISA, TISA, and LRSA isolates compared to MRSA.

Conclusions

During the three years of the study, “MIC creep” was observed in vancomycin, teicoplanin, and linezolid and, to some extent, for daptomycin in MRSA strains. The recovery of VISA, TISA, and linezolid-resistant MRSAs is worrisome, suggesting possible MRSA treatment failure and being a forerunner of resistant strains.

Background

Aptamers are not so new a concept, however, it is scarcely discussed by medical fraternity. Aptamers are potent, new identification molecules set to rope in a new technique in the diagnostic arena. Aptamers have started almost a revolution in diagnostic assays since their discovery in the 90s. (Radu S. Current and previous disease outbreaks around the world, U.S. News & World Report. 2020 Mar 13 [cited 2024 Jun 17]. Available from: https://www.usnews.com/news/best-countries/slideshows/20-pandemic-and-epidemic-diseases-according-to-who) provides an overview of pandemics and epidemics as reported by the WHO. It is interesting to note that several endemic and epidemic diseases viz. Chikungunya, Cholera, Crimean-Congo haemorrhagic fever, Ebola virus disease, Hendra virus infection, Influenza, Lassa fever, Marburg virus disease, Meningitis, MERS-CoV (Middle East Respiratory Syndrome Corona Virus), Monkeypox, Nipah virus infection, Novel coronavirus, Plague, Rift Valley fever, SARS (Severe Acute Respiratory Syndrome), Smallpox, Tularaemia, Yellow fever, and Zika virus disease have been identified by the WHO and are being explored for applicability of aptamer technology in their identification.

Objectives

One of the most important necessities to control epidemic or pandemic diseases is early diagnosis. However, the majority of the diagnostic tests for these diseases are available only in tertiary care centres. The objective of this review is to discuss the potential of aptamer technology to provide undemanding, simple, specific, sensitive, and cost-effective diagnostic assays that are useable in remote and field conditions.

Content

Here, we discuss recent advances and approaches in aptamer and aptamer engineering useful in the diagnosis of infectious and non-infectious conditions. This review also discusses a few sensing discoveries which are a gift of advanced engineering and technology using optical and electrochemical aptasensors. It's still a long way to go, and we need to take into account the technological challenges being faced by aptamer-aptasensor technology.

Background

In July 2022, the world health organization (WHO) announced the monkeypox virus (MPXV) as a public health emergency of international concern, due to the unprecedented global transmission of the disease beyond previously endemic countries in Africa.

Methods

For this systematic review, the author searched the “web of science” (WoS) database, which retrieves 138 articles on MPXV, published between 01-04–2022 and 22-09-2022. This period witnessed the maximum cases of infection as confirmed by the WHO. Seventy articles were used for in-depth analysis, after excluding papers not highly relevant to the topic.

Results and conclusions

The current review demonstrates different types of MPXV identification analysis, transmission of MPXV, clinical features, immune responses against MPXV, the mutations, and phylogenetic analysis. It also identifies the patients with high-risk complications and determines the other diseases related to MPXV. This paper provides suggestions for the suitable usage of vaccines or antiviral drugs as a procedure to control the outbreak and preventive strategies related to the humans. This research discusses significant implications and recommendations to contribute in reducing the spread of MPXV and presents avenues for upcoming MPXV research.

Purpose

The National Tuberculosis Elimination Programme (NTEP) of the Government of India has strived to control tuberculosis (TB) in the country through various interventions. Understanding the trends of resistance patterns may provide insights into the effectiveness of TB control activities in the country.

Methods

A total of 31,144 clinical samples were received from 2013 to 2022 from presumptive drug-resistant TB patients. All the specimens were decontaminated and subjected to the line probe assay for detection of resistance to rifampicin and isoniazid. Mycobacterium tuberculosis (MTB) was detected in 28,814 samples. Autoregressive integrated moving average model (ARIMA) was fitted to assess the trend over time.

Results

A decreasing trend in multi-drug resistant TB from 19 % in 2013 to 4 % in 2022 was seen. A decreasing trend in rifampicin monoresistance from 11.2 % in 2013 to 1.5 % in 2022 was seen, though there was an increase in resistance in 2017. No significant decreasing trends were seen in the proportion of isoniazid monoresistance from 8.3 % in 2013 to 7 % in 2022.

Conclusion

The findings are encouraging, and to a considerable extent, affirm that India is well on track with regard to the goal of TB elimination.

Anaerobic bacteria are rare but important cause of otogenic brain abscess. Improved patient management techniques and early clinical and laboratory diagnosis of otogenic infections are necessary to reduce the risk of intracranial complications. Here we present a case of recurrent pyogenic brain abscess caused by Bacteroides fragilis secondary to otitis media.

Multidrug -resistant tuberculosis (MDRTB) is a serious threat to mankind. India has the highest number of MDRTB cases, although majority remain undiagnosed due to inadequate diagnostic infrastructure, leading to increased community transmission and mortality. This one-year observational retrospective study highlighted the effectiveness of the National Tuberculosis Elimination Program (NTEP) for prompt detection of drug-resistant TB by GeneXpert MTB/RIF assay and revealed its associated clinico-epidemiological factors. The overall detection rates of MTB and RRTB were 20.70 % and 20.86 % respectively. The pediatric population had 7.69 % rifampicin resistance, and HIV was strongly associated with the development of TB and RRTB (P < 0.01).

Introduction

COVID-19 disease continues to be a global health concern. The current protocol for detecting SARS-CoV-2 requires healthcare professionals to draw blood from patients. Recent studies showed that dried blood spot (DBS) is a valuable sampling procedure that can collect a low blood volume without the need for the presence of medical practitioners. This study synthesized the available literature on using DBS as a blood collection tool to diagnose COVID-19 disease.

Materials and methods

A comprehensive search utilizing OVID, CINAHL, and Scopus databases was done from inception to March 2023. Five reviewers collected, extracted and organized the study data.

Results

This systematic review included 57 articles. DBS was commonly prepared by finger pricking. Most studies showed more favorable results and longer sample stability (more than 1080 days) with lower storage temperature conditions for the DBS. DBS samples were mostly used for serological assays for COVID-19 disease detection. ELISA was the most used detection method (43.66 %). Diagnostic performance of laboratory tests for COVID-19 using DBS sample showed high sensitivity of up to 100 % for immunoassay tests and 100 % specificity in agglutination, PCR, and DELFIA assays.

Conclusion

DBS sampling coupled with serological testing can be an alternative method for collecting blood and detecting COVID-19 disease. These tests using DBS samples showed excellent diagnostic performance across various geographic locations and demographics.