Hospital Isolates and Resistance Patterns

Evidence

This retrospective observational study reviewed clinical microbiology laboratory records at Bhatia Hospital in Mumbai, Maharashtra, India. It covered clinically significant bacterial and fungal isolates from inpatient and outpatient specimens received from January through December 2025. The analysis included 2,075 non-duplicate, clinically significant isolates. pmid:42763679

Investigators identified bacterial and fungal isolates with standard microbiological methods and the VITEK® 2 Compact system. They performed antimicrobial susceptibility testing with the same automated system and interpreted results under CLSI M100, 35th edition, 2025 guidelines. ESBL production was assessed with phenotypic confirmatory methods; MRSA was identified through cefoxitin resistance, and VRE through vancomycin MIC interpretation. Laboratory data were entered into Microsoft Excel, with categorical variables expressed as frequencies and percentages. pmid:42763679

Gram-negative bacteria were the predominant group, accounting for 1,627 of 2,075 isolates (78.4%). Gram-positive bacteria and fungal isolates were also represented, but the reported distribution indicates that the hospital’s isolate profile during the review period was led by Gram-negative organisms. pmid:42763679

Multidrug-resistant organisms accounted for 597 of 2,075 isolates (28.8%), and the study reported that MDRO prevalence differed significantly across clinical areas of isolation. The report also described comparatively better in vitro activity of reserve antimicrobial agents against susceptible isolates than of several commonly used β-lactam antibiotics and fluoroquinolones. These are laboratory susceptibility observations, rather than evidence comparing treatment effectiveness in patients. pmid:42763679

Analysis — Surveillance interpretation

The central contribution is a local surveillance snapshot: it brings organism distribution, susceptibility testing, and multidrug-resistance surveillance into one retrospective review of hospital laboratory records. The predominance of Gram-negative isolates and the reported MDRO burden make the findings relevant to how an institution maintains its antibiogram and frames antimicrobial-stewardship discussions. Because the work is based on clinically significant isolates rather than a treatment comparison, it describes the microbiological environment encountered in this setting; it does not show that one empirical regimen improves clinical outcomes over another. pmid:42763679

The reported difference in MDRO prevalence across clinical areas suggests that resistance patterns may vary by the setting from which isolates are obtained. That supports examining local data by care area rather than treating an institution-wide summary as interchangeable across every clinical context. However, the comparison is organism-dependent in the report, and the supplied evidence does not support extending this observation into a patient-level causal explanation. The reserve-agent finding likewise concerns in vitro activity among susceptible isolates, so it should not be equated with clinical benefit, safety, access, or appropriateness for any individual. pmid:42763679

For infection and immunity research readers, the study is most useful as an institutional microbiology and resistance-monitoring report. Its methods provide a defined laboratory framework for repeated local measurement, including standardized identification and susceptibility interpretation. Its stated implications concern continuous microbiological surveillance, regular institutional antibiogram updates, and antimicrobial stewardship. Those are surveillance-oriented uses of the evidence, not a prediction of resistance patterns at other hospitals or a basis for patient-specific conclusions. pmid:42763679

Limitations

The study was retrospective and conducted at a single center, which the authors state may limit direct generalizability to other healthcare settings. Its population was defined by clinical isolates and laboratory records, so the evidence does not provide a patient-level comparison of exposures, therapies, or outcomes. pmid:42763679

Molecular characterization of resistance mechanisms, including carbapenemase and ESBL genes, was not performed. The authors also state that patient-level clinical variables, antibiotic-exposure history, and treatment outcomes were beyond the scope of the analysis. These constraints limit interpretation of mechanisms and clinical consequences from the laboratory surveillance findings alone. pmid:42763679

Statistical significance in the reported variation in MDRO prevalence across clinical areas does not establish clinical significance. The results should therefore be read as locally generated susceptibility and distribution evidence, with uncertainty about how they translate across settings or into clinical outcomes. pmid:42763679