Characterization of antimicrobial resistance mechanisms of multidrug resistant Gram negative bacterial wound infections and their clinical epidemiology from a tertiary care hospital in Karnataka, India

Background: Extended spectrum beta lactamases, AmpC and Metallo-betalactamases in GNB isolates are a common occurrence in most Indian hospitals. The presence of these antimicrobial resistance mechanisms contributes to prolonged hospital stay, poor quality of life, increased morbidity and mortality among patients with these infections. The aim of the study was to analyse the antimicrobial resistance mechanisms of multidrug resistant Gram negative bacterial wound infection and their clinical epidemiology.Methods: A prospective study was conducted for one year among 100 patients of Kasturba Medical College, Manipal admitted with MDR GNB wound infections. The antibiogram and phenotypic resistance mechanisms of the bacterial isolate from these infections were identified using phenyl boronic acid and ethyl diacetate.  The empirical therapy, specific therapy and clinical outcome of the patients were also analyzed.Results: Out of 100 study patients, 152 MDR GNB isolates were obtained.  73% patients were admitted in the surgical wards. 43% patients had diabetes. Ulcers (27%) and abscess (25%) were the most common diagnosis. Escherichia coli (39%), Klebsiella pneumoniae (24%) and Pseudomonas aeruginosa (19%) were the most common isolates. Maximum number of ESBL was seen among Enteric Gram negative bacilli (36%), MBL was seen among Pseudomonas aeruginosa and Acinetobacter species (55% each), AmpC was seen among enteric GNB (10%) and Acinetobacter species (18%). Cefaperazone sulbactam, amikacin and meropenem were the most common antibiotics given as specific therapy. Clinical response was observed among 93% patients.Conclusions: The determination of the antimicrobial resistance mechanisms of GNB isolates from wound infections plays a major role in establishing an antibiotic policy for the treatment of these infections

Comparison of Three Phenotypic Methods of Carbapenemase Enzyme Detection to Identify Carbapenem-resistant Enterobacterales

The prevalence of multidrug-resistant gram-negative bacilli has increased worldwide. Critical care areas of most hospitals use carbapenem antibiotics for the empirical treatment of gram-negative bacterial (GNB) infections. In the last decade, there have been reports of the detection of carbapenem-resistant Enterobacterales (CRE). This rise in the spread of CRE presents a great challenge in the treatment of GNB infections and poses a serious threat to global health. To detect the burden of CRE and to characterize CRE, we used three phenotypic methods for the detection of carbapenemase enzymes. Using conventional aerobic bacterial culture methods, 150 Enterobacterales strains were isolated from various clinical samples. Identification of CRE was performed using multiple phenotypic detection methods, such as the Kirby Bauer disc diffusion method for meropenem (10 mcg) using the CLSI 2021 interpretation for meropenem, modified Hodge test (MHT), Carba NP test, and modified carbapenem inactivation method (mCIM) test. A total of 150 Enterobacterales strains were isolated over a period of 1 year. Among these, 66/150 (44%), 63/150 (43%), 64/150 (43%), and 65/150 (43%) were identified as CRE using the Kirby Bauer disc diffusion method, MHT, mCIM test, and Carba NP test, respectively. The sensitivity and specificity of MHT, mCIM, and Carba NP tests within 95% CI were 93.94%/100%, 96.97%/100%, and 98.48%/100%, respectively. The positive and negative predictive values of MHT, mCIM, and Carba NP tests were 100%/95.45%, 100%/97.67%, and 100%/98.82%, respectively. The accuracies of the MHT, mCIM, and Carba NP tests were 97.33%, 98.67%, and 99.33% respectively indicating a high burden of carbapenem resistance in Enterobacterales. Therefore, given the current statistics of carbapenem resistance, use of carbapenem as empiric treatment in the intensive care units of hospitals may not be beneficial. Identification of carbapenem resistance can help in the initiation of appropriate antimicrobial therapy. This study compares the accuracy and efficiency of Carba NP, mCIM, and MHT in detecting carbapenem-resistant Enterobacterales

Universal Coronavirus Testing to Control the Pandemic: Ethical Issues and Dilemmas

Every country had to make several difficult decisions in the initial phase of the Coronavirus (COVID-19) pandemic to allocate resources for COVID testing. Decisions on who should be tested for COVID-19 testing are extremely vital for pandemic preparedness. In this article, we highlight the need for prioritization of testing resources including direct-to-consumer testing methods, ethical dilemmas involved in obligatory testing, and testing of refugees and immigrants

Antimicrobial Resistance: A One Health Perspective in India

One health is a collaborative, multi-sectoral, trans-disciplinary approach used to achieve optimal health and well-being outcomes that recognize the interconnections among people, animals, plants, and their shared environment. This approach is crucial because animals and people are colonized by the same bacteria species and treated with the same antibiotic classes; the technique is instrumental in fighting antibiotic resistance. The microorganism developed antibiotic-resistant genes, which were transferred to the animal and human population via the environment. Human activities speed up the organism to acquire resistance rapidly. The primary sources of antimicrobial resistance from the environment were improper sewage and hospital waste sanitation, effluents from antibiotic production units, animal husbandry waste, agricultural manure use, livestock, and aquatic sources. This study analyzed the various routes by which antimicrobial-resistant gene is transferred into humans and their pathway in India. The study concludes that implementing strict regulation and monitoring regarding the irrational use of antibiotics in animals, sewage disposal, waste disposal, and hospital infection control practices, and providing awareness to the public regarding antibiotic resistance can reduce the rate of developing antibiotic resistance to some extent along with implementing antibiotic stewardship programmes for veterinary medicine

Susceptibility Profile of Nitrofurantoin and Fosfomycin among Carbapenem-resistant Enterobacteriaceae Isolates in UTI from a Tertiary Care Hospital

UTI is one of the most common infections requiring antibiotic treatment and hospitalization. The rising trend in multidrug resistance to commonly used antibiotics has reduced the therapeutic options for treating these infections. Reexploring older antibiotics like nitrofurantoin and fosfomycin provide treatment options and help combat resistance. This prospective study was conducted in the Department of Microbiology, SRM Medical College Hospital and Research Center, from July 2021 to February 2022. The study included only clean catch midstream urine isolates of Escherichia coli and Klebsiella pneumonia from hospitalized patients and outpatients. Standard microbiological procedures were used to process the urine samples. Direct gram stain and conventional biochemical reactions were performed to identify the isolates. The antimicrobial susceptibility testing was carried out by the Kirby Bauer disk diffusion method and Minimum Inhibitory Concentration by E- test gradient method for fosfomycin. MIC for nitrofurantoin was determined by Micro Broth Well Dilution according to CLSI guidelines 2021. Among 150 urine samples, Escherichia coli 107 (71.3%) was higher than Klebsiella pneumonia 43 (29%). Carbapenemase production was seen in 58 (63.04%) isolates by the Kirby Bauer disc diffusion method. Among the 58 positive carbapenemase producers, E. coli was found to be 33 (56.8%), and Klebsiella pneumonia was 25 (43.1%). Fosfomycin susceptibility rates by E test were reported to be high in Escherichia coli, ranging from 0.5-1mg/L. Klebsiella pneumonia was less susceptible to fosfomycin ranging from 16-32mg/L. Only 7(21%) isolates of Escherichia coli showed MIC of 1-4µg/ml to nitrofurantoin by broth microdilution. 21 (63.63%) isolates of Escherichia coli and 11(44%) isolates of Klebsiella pneumonia were reported to have an intermediate category with MIC of 8-32µg/mL. A higher MIC of 64- > 256µg/ml was shown by 5 (15.15%) isolates of Escherichia coli and 14 (56%) isolates of Klebsiella pneumonia. Older medications may resurface as useful therapeutic choices as resistance to current treatment options grow