Evaluation of a simple method for testing aztreonam and ceftazidime-avibactam synergy in New Delhi metallo-beta-lactamase producing Enterobacterales.

NDM-producing carbapenem-resistant bacterial infections became a challenge for clinicians. Combination therapy of aztreonam and ceftazidime-avibactam is a prudent choice for these infections. However, there is still no recommendation of a practically feasible method for testing aztreonam and ceftazidime-avibactam synergy. We proposed a simple method for testing aztreonam and ceftazidime-avibactam synergy and compared it with reference broth micro-dilution and other methods. Carbapenem-resistant Enterobacterales clinical isolates were screened for the presence of the NDM gene by the Carba R test. NDM harbouring isolates were tested for aztreonam and ceftazidime-avibactam synergy by broth microdilution (reference method), E strip-disc diffusion, double disc diffusion, and disc replacement methods. In the newly proposed method, the MHA medium was supplemented with ceftazidime-avibactam (corresponding to an aztreonam concentration of 4µg/ml). The MHA medium was then inoculated with the standard inoculum (0.5 McFarland) of the test organism. An AZT disc (30 µg) was placed on the supplemented MHA medium, and the medium was incubated overnight at 37°C. Aztreonam zone diameter on the supplemented MHA medium (in the presence of ceftazidime-avibactam) was compared with that from a standard disc diffusion plate (without ceftazidime-avibactam), performed in parallel. Interpretation of synergy was based on the restoration of aztreonam zone diameter (in the presence of ceftazidime-avibactam) crossing the CLSI susceptibility breakpoint, i.e., ≥ 21 mm. Of 37 carbapenem-resistant NDM-producing isolates, 35 (94.6%) were resistant to aztreonam and tested synergy positive by the proposed method. Its sensitivity and specificity were 97.14% and 100%, respectively. Cohen's kappa value showed substantial agreement of the reference method with the proposed method (κ = 0.78) but no other methods. The proposed method is simple, easily interpretable, and showed excellent sensitivity, specificity, and agreement with the reference method. Therefore, the new method is feasible and reliable for testing aztreonam synergy with avibactam in NDM-producing Enterobacterales.

Evaluation of three protocols for direct susceptibility testing for Gram-negative rods from flagged positive blood culture bottles.

Bloodstream infections are associated with high mortality, which can be reduced by targeted antibiotic therapy in the early stages of infection. Direct antibiotic susceptibility testing (AST) from flagged positive blood cultures may facilitate the administration of early effective antimicrobials much before the routine AST. This study aimed to evaluate three different direct AST protocols for Gram-negative rods from flagged positive blood culture broths. Blood culture broths showing Gram-negative rods only were subjected to direct AST by Clinical and Laboratory Standards Institute-recommended direct disk diffusion (protocol A). Additionally, automated AST (protocol B) and Kirby-Bauer disk diffusion (protocol C) were performed with standard inoculum prepared from bacterial pellets obtained by centrifuging blood culture broths in serum separator vials. For comparison, conventional AST of isolates from solid media subculture was also performed with Kirby-Bauer disk diffusion (reference standard) and the automated method. Overall, categorical agreements of protocols A, B, and C were 97.6%, 95.7%, and 95.9%, respectively. Among Enterobacterales, minor error, major error, and very major error rates of protocol B were 3.5%, 0.36%, and 0.43%, respectively, whereas minor error, major error, and very major error rates of protocol C were 3.4%, 0.72%, and 0.21%, respectively, and among non-fermenters, protocol B had a minor error rate of 6.5%, and protocol C had a minor error rate of 4.1% and major error rate of 1.9%. All three direct AST protocols demonstrated excellent categorical agreements with the reference method. Performance of protocols B and C between Enterobacterales and non-fermenters was not statistically different. IMPORTANCE: Bloodstream infections are associated with high mortality that can be reduced by targeted antibiotic therapy in the early stages of infection. Direct antibiotic susceptibility testing (AST) from flagged positive blood cultures may facilitate the administration of early effective antimicrobials much before the routine AST. Clinical and Laboratory Standards Institute-recommended direct AST can be performed with a limited number of antibiotic disks only. On the other hand, using an automated system for direct AST will not only allow effective laboratory workflow with reduced turnaround time but also provide the minimum inhibitory concentration values of tested antibiotics. However, using expensive automated systems for direct AST may not be feasible for resource-limited laboratories. Therefore, in this study, we aimed to evaluate the CLSI-recommended method and two other direct AST protocols (one with an automated system and the other with disk diffusion) for Gram-negative rods from flagged positive blood cultures.

Evaluation of a rapid immunochromatographic test for the diagnosis of intestinal protozoan infections among patients attending a rural outreach outpatient department in Northern India.

Despite great efforts, intestinal protozoan infections remain a significant healthcare concern worldwide. Although many point-of-care (POC) tests are increasingly being used, microscopic examination of stool specimens remains the mainstay for their diagnosis, especially in resource-limited settings. We assessed the utility of rapid POC tests based on immunochromatography among patients from rural Northern India. A total of 78 patients were enrolled in the study. Out of nine specimens that tested positive for Giardia duodenalis on microscopy, an immunochromatographic test (ICT) could detect only five (55.55%). Entamoeba histolytica/dispar was demonstrated in two specimens on microscopy, both of which were missed by ICT. Its overall sensitivity, specificity, and positive and negative predictive value were 50%, 98.5%, 83.3%, and 93%, respectively. Its performance was considered unsatisfactory. Although ICT-based tests provide a relatively rapid and less labor-intensive alternative, they should be used to supplement and not replace stool microscopy.

Breakthrough infection among healthcare personnel following exposure to COVID-19: Experience after one year of the world's largest vaccination drive.

Context: The COVID-19 vaccination drive globally was supposedly a game-changing event. However, the emerging variants of the virus and waning immunity over time posed new challenges for breakthrough infections. Standing at the frontline of defense against COVID-19, healthcare personnel (HCP) were vulnerable to such infections. Aims: This study estimates i) the vaccine breakthrough infections (VBI) among HCP following exposure to COVID-19 cases, and ii) the mean interval between the second dose of vaccine and laboratory-confirmed SARS-CoV-2 infection. Materials and Methods: A cross-sectional study was conducted including 385 HCP with a history of exposure to COVID-19 cases during January and February 2022. Demographic details and clinical and vaccination history were collected from the test forms and the Web-based hospital management system. Laboratory testing of COVID-19 was carried out by real-time RT-PCR test. Results: The majority of the HCP were males (262; 68.05%) and nurses (180; 46.75%) by occupation. Two doses of vaccines were received by 278 (87.7%) HCP. VBI was confirmed in 185 (66.55%) HCP. No significant difference in VBI between the COVAXIN and COVISHIELD recipients (P = 0.69) was observed. The interval between the second dose and confirmed SARS-CoV-2 infection was significantly higher (P < 0.00001) in COVAXIN recipients (median 228 days) than in COVISHIELD recipients (median 95 days). Conclusions: The incidence of VBI was very high among the HCP, but not statistically different among the COVAXIN and COVISHIELD-recipients. Waning immunity over time suggests boosting immunity with a third dose because of emerging variants.

Relevance of Conventional Microscopy in the Diagnosis of Mucormycosis during COVID-19 Pandemic.

Introduction: Mucormycosis is a lethal disease which bewildered the health-care community of India during the ongoing second wave of the COVID-19 pandemic. The diagnosis is challenging considering the poor isolation in culture. Aims: The aim of the study was to emphasize the utility of potassium hydroxide (KOH) mount examination using conventional light microscopy for early diagnosis of mucormycosis in resource-limited settings. Materials and Methods: A retrospective analysis of results for all the samples including tissue biopsies, swabs, and pus received in the laboratory for KOH microscopy was done, and results were recorded. The clinical and demographic details of the patients were collected from the hospital information system. Results: A total of 75 samples from 50 patients were received in the laboratory. Out of these, 43 samples from 35 patients showed fungal hyphae (38 patients with only nonseptate hyaline hyphae, 2 with septate hyaline hyphae, and 3 samples with mixed infections). All patients except one were positive for severe acute respiratory syndrome coronavirus 2 infection. The most common age group was 45-59 years (40%), followed by 30-44 years (34.28%) with a male predominance. There was a significant difference in hemoglobin A1C (P = 0.005) and ferritin (P = 0.017) levels between laboratory-confirmed mucormycosis patients and clinically suspected mucormycosis patients without confirmation. Conclusion: Early diagnosis and initiation of targeted therapy is the cornerstone for treating mucormycosis patients. Hence, a rapid and reliable mode of diagnosis is the need of the hour. Conventional microscopy is such a tool that may be used, especially in resource-limited settings.

Persistence of SARS-CoV-2 in COVID-19 patients during the second wave of the pandemic in India.

INTRODUCTION: India witnessed the catastrophic second wave of COVID-19 during the summer months of 2021. Many patients with non-resolution of symptoms admitted to dedicated COVID-19 treatment centers required prolonged inpatient care which led to the unavailability of beds for other COVID-19 patients. The objective of this study was to determine the duration of SARS-CoV-2 positivity in moderate and severe COVID-19 patients requiring long-term pulmonary care as well as to find out the association between different variables with the persistence of the virus. METHODOLOGY: A retrospective chart review of clinical and laboratory data of patients with moderate and severe COVID-19 between 1st April 2021 and 15th July 2021 admitted for more than 28 days and requiring long-term pulmonary care was carried out at National Cancer Institute, AIIMS, India. SARS-CoV-2 RNA was detected with real-time reverse transcriptase-polymerase chain reaction-based tests. Data from all consecutively included patients satisfying the selection criteria were presented temporally and analyzed by Fisher's exact test (p < 0.05). RESULTS: All 51 patients tested positive for SARS-CoV-2 RNA at the 5th week of initial laboratory confirmation of COVID-19. The majority of the patients (38; 74.5%) remained positive for viral RNA till the 6th week and the median duration of viral positivity was 45 days. The clinical presentation of SARI at admission was significantly higher among patients with viral persistence till the 6th week (p < 0.05). CONCLUSIONS: The median duration of the viral positivity was 45 days and SARI at admission was significantly associated with viral persistence till the 6th week.

Challenges in setting up a diagnostic microbiology laboratory during coronavirus disease 2019 crisis and impact on the diagnosis of communicable diseases.

The coronavirus disease 2019 (COVID-19) pandemic has left the health-care workers exhausted and the system dwindling. The challenges have been immense everywhere and even worse in developing countries. Despite the Indian Government's forethought and active investment in various national programs, the pandemic has brought unconceivable repercussions on the management and notification of several other lethal infectious diseases including human immunodeficiency virus (HIV) and tuberculosis. Although the phenomenal capacity building for COVID-19 testing and diagnosis over a short time is admirable, the journey has been arduous. From convincing the hospital managements to create the recommended infrastructure, to the procurement of necessary equipment and consumables on an urgent basis, and providing services round the clock with limited workforce, the laboratory personnel throughout the country have done a remarkable job in their quest to combat the pandemic. However, the work needs to be pursued further in apprehension and preparedness for any emerging agents.

Clinical features, demography, and predictors of outcomes of SARS-CoV-2 infection at a tertiary care hospital in India: A cohort study.

BACKGROUND: The "second wave" of the COVID-19 pandemic hit India from early April 2021 to June 2021. We describe the clinical features, treatment trends, and baseline laboratory parameters of a cohort of patients with SARS-CoV-2 infection and their association with the outcome. METHODS: This was a retrospective cohort study. Multivariate logistic regression models were fitted to identify clinical and biochemical predictors of developing hypoxia, deterioration during the hospital stay, and death. RESULTS: A total of 2080 patients were included. The case fatality rate was 19.5%. Among the survivors, the median duration of hospital stay was 8 (5-11) days. Out of 853 (42.3%%) of patients who had COVID-19 acute respiratory distress syndrome at presentation, 340 (39.9%) died. Patients aged >45 years had higher odds of death as compared to the 18-44 years age group. Vaccination reduced the odds of death by 40% (odds ratio [OR] [95% confidence interval [CI]]: 0.6 [0.4-0.9], P = 0.032). Patients with hyper inflammation at baseline as suggested by leukocytosis (OR [95% CI]: 2.1 [1.5-3.1], P < 0.001), raised d-dimer >500 mg/dL (OR [95% CI]: 3.2 [2.2-4.7], P < 0.001), and raised C-reactive peptide >0.5 mg/L (OR [95% CI]: 3.7 [2.2-13], P = 0.037) had higher odds of death. Patients who were admitted in the 2nd week had lower odds and those admitted in the 3rd week had higher odds of death. CONCLUSION: This study shows that vaccination status and early admission during the inflammatory phase can change the course of illness of these patients. Improving vaccination rates and early admission of patients with moderate and severe COVID-19 can improve the outcomes.

Antimicrobial resistance and COVID-19 syndemic: Impact on public health.

The COVID -19 pandemic has had a catastrophic impact on the global economy and the healthcare industry. Unfortunately, the scientific community still hasn't discovered a definite cure for this virus. Also, owing to the unscrupulous use of antibiotics in wake of the current situation, another ongoing pandemic of antimicrobial resistance (AMR) has been entirely eclipsed. However, increased compliance to infection control measures like hand hygiene (both at hospital and community level), and restricted travel might be favorable. It is evident that the AMR strategies will be impacted disproportionately varying with the respective policies followed by the countries and hospitals to deal with the pandemic. The vaccination drive initiated globally has provided a glimmer of hope. In this article, the possible reciprocity between the two contemporaneous pandemics has been addressed. The world needs to be vigilant to punctuate the symphony between these lethal threats to global health. The restraint to combat against AMR will be boosted as our discernment of the problem also changes with the epidemiological interplay becoming more apparent in near future.