Morubagal Raghavendra Rao

Klebsiella pneumoniae (K. pneumoniae) is a high-priority antibiotic-resistant pathogen contributing significantly to the global burden of antimicrobial resistance (AMR). Extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases are major resistance mechanisms commonly observed in K. pneumoniae. The present study aimed to determine the prevalence and distribution of ESBL and AmpC β-lactamase production and to evaluate associated antimicrobial resistance patterns among clinical isolates. A prospective laboratory study was conducted over one year (January-December 2020) in a tertiary care hospital, South India. Total of 100 clinical isolates of K. pneumoniae were included. Identification and antimicrobial susceptibility testing (AST) were performed using the VITEK 2 compact system, while ESBL and AmpC production were detected using standard phenotypic methods. AST demonstrated markedly high resistance rates to carbapenems (meropenem, ertapenem and imipenem), fluoroquinolones (ciprofloxacin), cephalosporins (cefuroxime, ceftriaxone, and cefepime), and β-lactamase inhibitors. Overall, 53% (n = 53) of isolates were ESBL producers, 48% (n = 48) were AmpC producers, while 24% (n = 24) exhibited co-production of both enzymes. The proportion of co-producers represents a considerable subset, suggesting a clinically relevant association with multidrug-resistance. The association between ESBL and AmpC β-lactamase production was found to be statistically not significant (P-value = 0.49). The co-existence of ESBL and AmpC enzymes was associated with a higher resistance burden across multiple antibiotic classes, underscoring its potential impact on therapeutic outcomes. These findings highlight a substantial prevalence of β-lactamase-mediated resistance and emphasize the need for continuous surveillance, implementation of robust antimicrobial stewardship programs, and proper infection control strategies to limit the spread of multidrug-resistant K. pneumoniae.

Multidrug-resistant (MDR) Acinetobacter is an important pathogen which has a number of virulence characters that enable them to render resistance to antibiotics thus complicating the treatment options, thereby forcing clinicians to rely on last resort antibiotic such as colistin. However, resistance to colistin has also been reported, further increasing the challenge. To detect the rate of colistin resistance and carbapenemase production among MDR Acinetobacter baumannii isolates from a tertiary care hospital in South India. This is a prospective study conducted over a period of 15 months from August 2023 to October 2024 and included 110 isolates of MDR Acinetobacter baumannii. All the isolates were subjected to colistin resistance detection using microbroth dilution method and carbapenemase production using mCIM and eCIM methods. Of the 110 isolates of MDR A. baumannii, 19 (17.27%) showed colistin resistance. The mCIM and eCIM tests showed 70 (63.63%) serine carbapenemase producers and 61 (55.45%) metallo beta-lactamase producers. This study underscores the concerning prevalence of resistance determinants among MDR A. baumannii, providing clinicians and infection control specialists with essential data to guide the formulation of effective empirical treatment strategies and infection control measures.

Background: Lower respiratory tract infections (LRTIs) represent a significant clinical burden necessitating accurate microbiological diagnosis to guide targeted antimicrobial therapy. The quality of sputum specimens substantially influences the validity of culture results and diagnostic reliability. The Bartlett scoring system (BS) is a standardized, objective tool for assessing sputum specimen quality. However, its clinical utility in predicting culture positivity within tertiary care settings remains inadequately characterized in existing literature. Methods: A clinical audit was conducted on 212 consecutive sputum samples from patients with suspected LRTIs collected during September and October 2023 at a tertiary care center. All specimens underwent direct microscopy examination with concurrent assessment using the Bartlett scoring system (range 0–4). Samples meeting quality criteria (BS≥2) were processed for culture using standard microbiological techniques. Culture positivity rates were correlated with Bartlett scores to determine the association between sample quality assessment and microbiological yield. Results: Among the 212 sputum samples analyzed, specimens with higher Bartlett scores demonstrated significantly increased culture positivity rates, establishing a positive correlation between sample quality assessment and microbiological diagnostic yield. Samples classified as high-quality (BS≥2) demonstrated superior diagnostic utility compared to lower-quality specimens. The Bartlett scoring system, when applied systematically in conjunction with direct microscopy, facilitated objective specimen selection and enhanced laboratory processing efficiency. Conclusions: This audit demonstrates that the scientific utility of Bartlett scoring system serves as a valuable objective tool for assessing sputum quality and predicting culture positivity.

Multidrug resistant (MDR) Acinetobacter is an important pathogen which has a number of virulence characteristics that enable them to render resistance to antibiotics thus complicates the treatment options, thereby forcing clinicians to rely on last resort antibiotic such as colistin. However, resistance to colistin has also been reported, further increasing the challenge. To detect the virulence attributes, colistin resistance and carbapenemase production in MDR Acinetobacter baumannii from a tertiary care hospital in South India. This is a prospective study conducted over a period of 15 months from August 2023 to October 2024 with 110 isolates of MDR Acinetobacter baumannii. All the isolates were subjected to colistin resistance detection using microbroth dilution method, carbapenemase detection using mCIM and eCIM methods, virulence detection like biofilm production by tissue culture plate method, haemolytic activity on blood agar, proteolytic activity on milk agar and siderophore production on Chrome Azurol S agar. Of the 110 isolates of MDR A. baumannii, 19 (17.27%) showed colistin resistance, 89 (80.90%) showed biofilm production, 35 (31.81%) showed haemolysis, 60 (54.54%) showed proteolysis and 49 (44.54%) showed siderophore production. The serine carbapenemase from mCIM and metallo beta-lactamase producers from eCIM tests were 61 (55.45%) serine carbapenemase and 70 (63.63%) respectively. This study underscores the concerning prevalence of virulence and resistance determinants among MDR A. baumannii, providing clinicians and infection control specialists with essential data to guide the formulation of effective empirical treatment strategies and infection control measures.

Carbapenemase detection amongst Acinetobacter baumannii and Klebsiella pnuemoniae - IJMMTD- Print ISSN No: - 2581-4753 Online ISSN No:- 2581-4761 Article DOI No:- 10.18231/j.ijmmtd.2025.008, IP International Journal of Medical Microbiology and Tropical Diseases-IP Int J Med Microbiol Trop Dis

Gram-negative bacterial infections that are resistant to carbapenems are a serious clinical problem. The only effective drugs against them are still tigecycline and colistin. In fact, polymyxin E, also known as colistin, has been regarded as a "last resort" antibiotic. But in recent years, colistin resistance has increased globally, significantly reducing treatment options and highlighting the significance of accurate colistin testing methods to support appropriate therapeutic decision-making. There is no requirement to cite reference in the So it is suggested to rephrase the sentence. The primary goal of the study is to compare the effectiveness of E-test and Vitek 2 for colistin sensitivity testing to the conventional microbroth dilution method using 120 clinical isolates of and that are resistant to carbapenem over the course of a year, isolated from January to December 2019. In comparison to Vitek-2, the results indicated that brothmicro dilution and E-test produced the narrowest range of colistin MICs. After comparing the E-test's errors and overall agreement with BMD, 100% of the Essential Agreement, 94.27% of the Categorical Agreement, and 5.72% of the Very Major Errors with no Major Errors were found. Comparing Vitek-2 with BMD, similar results were found: 1.66% MEs, 98.32% CAs, 80.99% EAs, and no VMEs. As a result, it was determined that, in contrast to Vitek-2, MBD and E-test had distinct MICs, making them appropriate for determining colistin MIC. It will take more research on automated systems to standardize colistin susceptibility testing procedures, particularly for and .

Tuberculosis (TB), a dreadful disease known to mankind continues to be a problem in a developing country like India. The incidence of people getting infected with TB is on the rise due to compounding factors like coinfection with the human immunodefiency virus and multidrug-resistant strains. There is a definitive need for early diagnosis and treatment of TB to curb transmission of the infection. Direct smear microscopy, though cheap and rapid, lacks sensitivity. Isolation of Mycobacterium tuberculosis in culture requires a long time, because of which there is a need for a rapid method which has good sensitivity and specificity for the detection of M. tuberculosis. Hence the present study was undertaken to determine Performance of rapid slide culture method for confirming pulmonary tuberculosis in clinically suspected and smear positive cases and also to assess the factors responsible for poor outcomes in the study population.

Salmonella enterica serovar Kentucky is an emerging human pathogen in developed countries and also a concern for public health in developing countries. Although genus Salmonella is usually susceptible to many antimicrobial agents, a recent increase in resistance has become a cause for concern. A case of ceftriaxone resistant Salmonella enterica serovar Kentucky causing bacteremia and acute gastroenteritis is reported in this paper. The Salmonella Kentucky isolate in this case was resistant to most classes of antibiotics. This is the first case report of Salmonella enterica serovar Kentucky resistant to ceftriaxone. Multidrug resistant patterns of Salmonella Kentucky are observed globally. Awareness of various nontyphoid Salmonella causing human infections is of utmost importance, because delayed identification, serotyping, and susceptibility testing may delay the administration of antibiotics leading to worsening outcomes.

Diphtheria is a vaccine-preventable disease and is caused by toxigenic strains of Corynebacterium diphtheriae. Several case reports have been published in the recent years, and this resurgence of cases has occurred mainly in adolescent and adult populations. Also, several research articles have reported waning immunity against diphtheria in adults who have completed childhood immunization. Thus, it is an important need to conduct larger sero-surveillance studies to understand the cause of rising diphtheria cases. Here, we report a case of a 23-year-old pregnant women of 8 weeks’ gestation who presented to the outpatient department with fever, severe throat pain, odynophagia, dysphagia, neck pain, and neck swelling of 3 days’ duration. On clinical examination, a gray, leathery membrane was noted on the soft palate. An Albert’s stain from the membrane revealed organisms resembling Corynebacterium diphtheriae. Appropriate treatment was initiated immediately, and follow-up examination at 2 weeks from date of discharge was uneventful. The gray membrane had completely resolved. Contact tracing was done and the appropriate antimicrobial agent was administered. This case study indicates the importance of timely clinical and microbiological diagnosis and reinforces the previously reported resurgence of diphtheria infection.