Modified Carbapenem Inactivation Method and Ethylenediaminetetraacetic Acid (EDTA)-Carbapenem Inactivation Method for Detection of Carbapenemase-Producing Enterobacterales and Pseudomonas aeruginosa.

INTRODUCTION: The rising incidence of carbapenem resistance in Enterobacterales and Pseudomonas aeruginosa is a concern. Since carbapenemase production is the primary resistance mechanism, detecting and identifying the genes responsible for it is crucial to effectively monitor its spread. OBJECTIVE: This study aims to detect positivity for the modified carbapenem inactivation method (mCIM) and ethylenediaminetetraacetic acid (EDTA)-carbapenem inactivation method (eCIM) for the detection of carbapenemase-producing Enterobacterales and Pseudomonas aeruginosa. METHODS: Methods: A cross-sectional study was carried out at a tertiary care hospital, including 250 clinical isolates of Enterobacterales and Pseudomonas aeruginosa. These isolates exhibited resistance to at least one of the carbapenems as determined by the VITEK AST 2 System (bioMérieux, USA). The isolates were subjected to mCIM testing, and those that tested positive were further tested using eCIM. The results were interpreted in accordance with the guidelines provided by the Clinical and Laboratory Standards Institute (CLSI) 2023. RESULTS: Out of the total 250 carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa isolates, 151 (60.4%) were Klebsiella pneumonia, 44 (17.6%) were Escherichia coli, 10 (4.0%) were Enterobacter cloacae, 6 (2.4%) were Providencia spp., 4 (1.6%) were Serratia marcescens, 4 (1.6%) were Proteus mirabilis and 31 (12.4%) were Pseudomonas aeruginosa. Positivity for the mCIM was observed in 96% (240 out of 250) of the isolates. Of the mCIM-positive isolates, 234 (97.5%) also tested positive for eCIM, indicating metallo-ß-Lactamase (MLB) production. A statistically significant association was found between both mCIM and eCIM positivity and the degree of resistance to carbapenem (p<0.05). Conclusion: This study shows that the inexpensive method, a combination of mCIM and eCIM assists in differentiating between serine carbapenemase producers and MLB producers, thereby guiding the selection of appropriate therapy and useful in infection control in resource-limited settings.

Evaluation of In-Vitro Activity of Ceftaroline Against Methicillin-Resistant Staphylococcus aureus Clinical Isolates.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of hospital and community-acquired infections. Fewer drugs, such as vancomycin, teicoplanin, and daptomycin, are effective against it, but they come with high toxicity. Fifth-generation cephalosporins like ceftaroline and second-generation cefuroxime are effective against MRSA. Limited studies are available on ceftaroline resistance in the literature. This study was undertaken to determine ceftaroline resistance in MRSA in a tertiary care hospital in Eastern India. A cross-sectional, hospital-based study was carried out with MRSA isolates obtained from various clinical samples of patients. Identification of the isolates to the species level was performed by an automated Vitek system, and selected samples were genotypically confirmed by detecting the mecA gene via real-time PCR. Out of a total of 334 Staphylococcus aureus isolates examined in this study, the prevalence of MRSA was seen in 59.3% (198/334), and methicillin-sensitive Staphylococcus aureus was in 40.7% (136/334). Of the total 198 MRSA isolates, ceftaroline intermediate MRSA was seen in 8.6% (17/198), and ceftaroline sensitive MRSA was in 91.4% (181/198), respectively. Among the 17 ceftaroline intermediate MRSA isolates, 88.2% (15/17) showed a minimum inhibitory concentration (MIC) of 2 µg/ml, and 11.8% (2/17) showed an MIC of 3 µg/ml. All the remaining 91.4% (181/198) isolates were sensitive to ceftaroline and showed an MIC ≤1 µg/ml. Real-time PCR confirmed the presence of the mecA gene in MRSA isolates. In this present study, not a single isolate was resistant to ceftaroline, suggesting that it, being a safer drug, can be used in place of glycopeptides such as vancomycin or teicoplanin and linezolid, where resistance has already been detected. The rational use of ceftaroline could be useful in clinical settings, and further studies will confirm the findings.

Correlation of Breakthrough Infection During the Omicron Wave With Seropositivity of Vaccinated Patients Undergoing Hemodialysis.

Background Patients with chronic kidney disease and undergoing hemodialysis are at greater risk of developing COVID-19. In spite of vaccine efficacy, SARS-CoV-2 breakthrough infection has been reported in several studies. This study was carried out to assess if seroconversion could predict SARS-CoV-2 breakthrough infection in a cohort of vaccinated patients undergoing hemodialysis. Methodology Patients undergoing maintenance hemodialysis for at least three months and who had received two doses of BBV152 or AZD1222 vaccine were included in the study. Their baseline IgG antibodies to SARS-CoV-2 were measured and followed up for a median of three months during the third wave of COVID-19 in India with SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) to detect breakthrough infections. Results Of 80 patients enrolled, seroconversion was seen in 81% of the cases, and SARS-CoV-2 breakthrough cases have been detected in 16% (13/80; 95% CI 8.95-26.18) patients undergoing hemodialysis. Of the 13 patients, seven patients required hospitalization and others had a mild outcome. There was no correlation of baseline seropositivity with breakthrough infections or hospitalization. Conclusions A majority of patients who underwent hemodialysis are seropositive post-vaccination. The breakthrough infection did not correlate with baseline seroconversion. Thus, there would be other predictors of breakthrough COVID-19 infections that need to be recognized in this susceptible population.

Colistin Resistance Among Multi-Drug Resistant Gram-Negative Bacterial Isolates From Different Clinical Samples of ICU Patients: Prevalence and Clinical Outcomes.

INTRODUCTION: Colistin is considered to be the last resort for the management of infections caused by multi-drug resistant (MDR) gram-negative bacilli (GNB). However, in the recent past, there has been a rise in colistin resistance among MDR isolates in clinical settings with no profound data on the incidences and causes. The purpose of this study was to estimate the prevalence of colistin-resistance (CLR) in MDR isolates collected from different intensive care units (ICUs) and to determine the clinical outcomes of the patients.  Materials and methods: A prospective study was conducted in the ICU of a tertiary care hospital in Eastern Odisha, India from March 2019 to February 2020. MDR GNB isolates from different clinical samples of ICU patients, not intrinsically resistant to colistin, were included in this study. Samples collected for culture and sensitivity testing were processed as per standard guidelines in the microbiology laboratory. MDR organisms were examined for colistin susceptibility by the broth dilution method. Clinical data was collected from hospital electronic medical records and presented as percentage, number (N), and median (range). RESULTS:  The prevalence of colistin resistance MDR GNB was found to be 19.6% in the present study. Colistin resistance among the MDR isolates was found to be the highest (9.2% for Klebsiella pneumonia followed by 5% for Escherichia coli). CLR drug-resistant isolates were commonly (28.8%) isolated from samples of respiratory tract infections and the majority (54.1%) were from neurology ICU. In this study, co-morbidity was not found among 57.9% of the ICU patients and recovery was maximum i.e., 74.2%. CONCLUSION: This study found the prevalence of colistin resistance to be high (19.6%) among all MDR GNB isolates from samples of ICU patients, Klebsiella pneumonia and Escherichia coli commonly acquire colistin resistance. Patients in the neurology ICU were frequently infected with CLR MDR strains. Most of the patients who recovered were without any underlying comorbidities. Prolonged hospital stay and direct antibiotic pressure in the hospital can lead to the development of CLR variants.

Aloe vera mouthwashes can be a natural alternative to chemically formulated ones - A randomized-controlled trial.

Objectives: To evaluate the antiplaque and antibacterial efficacy of commercially available mouthwashes containing aloe vera (AV), hydrogen peroxide (HP), and cetylpyridinium chloride (CPC) in a 4-day plaque regrowth study. Methods: Plaque score and salivary samples were assessed (Day-0 and Day-4) in 96 participants in a randomised, double-blind prospective parallel-arm 4-day plaque regrowth study. Participants were divided into five groups who refrained from engaging in regular oral hygiene measures during the study period and used commercially available mouthwashes containing AV, HP, and CPC as test products with distilled water (DW) and chlorhexidine (CHX) mouthwash as negative and positive controls, respectively. Salivary bacterial count was expressed as colony-forming units (CFU) (culture method). Results: There was a significant difference both in plaque score (p < 0.001) and in CFU (p < 0.001) among the study mouthwashes at Day-4. The plaque score and CFU of AV were significantly higher and lower than those of CHX and DW, respectively. The plaque score of HP was significantly higher than that of AV (p = 0.016) and CPC (p < 0.001). No significant difference was observed between AV and CPC (p = 0.70). Moreover, the CFU of HP was significantly higher than that of CPC (p = 0.04). There was no statistically significant difference between the CFU of mouthwashes containing AV and HP (p = 0.912) or AV and CPC (p = 0.280). No significant difference was seen in the inhibition of plaque and salivary bacterial count between AV, HP, and CPC. Conclusion: The antiplaque and antibacterial efficacy of commercially available AV mouthwash was similar to that of CPC and significantly better than that of HP mouthwash and can be a natural alternative to chemically formulated mouthwashes.

Comparative Evaluation of Cartridge-Based Abbott ID NOW Test With Probe-Based Real-Time Reverse Transcription Polymerase Chain Reaction Assay for Detection of SARS-CoV-2.

BACKGROUND: The gold standard test for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recommended by WHO is real-time reverse transcription polymerase chain reaction (RT-PCR), which has a turnaround time of five to six hours. Abbott ID NOW (Abbott Diagnostics Scarborough, Inc., Scarborough, ME, USA), the cartridge-based loop-mediated isothermal amplification (LAMP) assay, was approved by FDA for Emergency Use Authorization as rapid point of care testing. The present study was planned to evaluate the performance of the cartridge-based Abbott ID NOW test by comparing it to the currently used standard probe-based real-time RT-PCR method for detection of SARS-CoV-2. METHODOLOGY: A cross-sectional study was conducted in a tertiary care hospital in the eastern part of India after getting institutional ethics committee (IEC) approval. Two hundred fifty-nine cases of various age groups of both sexes who were advised for testing for SARS-CoV-2 were included in the study. Nasopharyngeal swabs were collected according to protocol advisory by the Indian Council of Medical Research (ICMR), India. Dry swabs were sent for Abbott ID NOW testing and swabs in viral transport medium were sent for probe-based RT-PCR assay using the CoviPath kit (Thermo Fisher Scientific, Bangalore, India). The data were collected and statistical analysis was performed using Statistical Package for Social Sciences (SPSS) (IBM Corp., Armonk, NY, USA). Sensitivity, specificity, positive and negative predictive values for ID NOW were calculated taking RT-PCR as the gold standard.  Results: Out of 259 patients enrolled in the study, 49% were symptomatic for coronavirus disease 2019 (COVID-19). The prevalence rate of SARS-CoV-2 was 20.84% among the study population. Sensitivity and specificity, positive and negative predictive values of ID NOW test in comparison to RT-PCR assay was found to be 87%, 98%, 92.1% and 96.8% respectively. ID NOW detected seven out of 54 (12.9%) cases as false negative who were found to be positive with RT-PCR, with mean Ct value of the target genes >34. CONCLUSIONS: In this study the overall sensitivity for ID NOW assay was found to be lower, but specificity, positive and negative predictive values were found to be higher. It had the highest correlation to RT-PCR among symptomatic patients and at higher viral loads. Due to the ease of use and shortest result time for detecting COVID-19, ID NOW test could be used as a point-of-care test. But for all tests, the results should be interpreted according to the clinical and epidemiological context.

Assessment of non-invasive models for liver fibrosis in chronic hepatitis B virus related liver disease patients in resource limited settings.

CONTEXT: A total of 350 million individuals are affected by chronic hepatitis B virus infection world-wide. Historically, liver biopsy has been instrumental in adequately assessing patients with chronic liver disease. A number of non-invasive models have been studied world-wide. AIM: The aim of this study is to assess the utility of non-invasive mathematical models of liver fibrosis in chronic hepatitis B (CHB). Indian patients in a resource limited setting using routinely performed non-invasive laboratory investigations. SETTINGS AND DESIGN: A cross-sectional study carried out at a tertiary care center. SUBJECTS AND METHODS: A total of 52 consecutive chronic liver disease patients who underwent percutaneous liver biopsy and 25 healthy controls were enrolled in the study. Routine laboratory investigations included serum aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Gama glutamyl transpeptidase (GGT), total bilirubin, total cholesterol, prothrombin time and platelet count. Three non-invasive models for namely aspartate aminotransferase to platelet ratio index (APRI), Fibrosis 4 (FIB-4) and Forn's index were calculated. Outcomes were compared for the assessment of best predictor of fibrosis by calculating the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of each index. STATISTICAL ANALYSIS USED: Medcalc online software and by Microsoft Excel Worksheet. Chi-square test was used for significance. P value < 0.05 was taken as significant. RESULTS: While the serum levels of AST, ALT and GGT were significantly higher in patients group as compare with the healthy controls (P < 0.01), the platelet counts were significantly lower in patient group as compared to the control group (P < 0.01). Mean value of all 3 indices were significantly higher in patients group as compare with the controls (P < 0.01). CONCLUSIONS: Out of the three indices, APRI index with a NPV of 95% appeared to be a better model for excluding significant liver fibrosis while FIB-4 with a PPV of 61% showed fair correlation with significant fibrosis. Thus, these two non-invasive models for predicting of liver fibrosis, namely APRI and FIB-4, can be utilized in combination as screening tools in monitoring of CHB patients, especially in resource limiting settings.