Unveiling the antibiotic resistance pattern in Staphylococcus aureus: A systematic review (2013-2024)

Abstract

BACKGROUND

Staphylococcus aureus (S. aureus) is one of the six highly pathogenic nosocomial bacteria. These bacteria develop or evolve with several antibiotic resistance mechanisms and therefore known to escape antibiotic treatments. Several reports suggest that multidrug resistance in S. aureus is increasing worldwide over the time. Indian population is comprised of diverse ethnic group residing different geographical regions. Recent reports revealed that antibiotic resistance in S. aureus isolates vary in different regions of India.

AIM

To identify antibiotic resistance pattern in S. aureus in India.

METHODS

In the present study, we overviewed resistance in S. aureus isolates to different antibiotics. We searched for the research articles on antibiotic resistance in S. aureus from India using Scopus, Google scholar, and PubMed databases (Prospero registration No. PROSPERO 2025CRD420251153034). We identified a total of 26 articles published during 2013 to 2024 in English language. We extracted the information about the location of the study, antibiotics used and percentage of the resistant isolates.

RESULTS

Among 26 studies, most of the studies were reported from northern India (31%), southern India (27%) and eastern India (27%), followed by western India (11%) and Pan India (4%). The findings highlight very high resistance to beta-lactam antibiotics, particularly penicillin and methicillin, reflecting a substantial burden of methicillin-resistant S. aureus. Fluoroquinolones and macrolides also showed elevated resistance levels, whereas linezolid, teicoplanin, chloramphenicol, and doxycycline retained comparatively better activity.

CONCLUSION

The present review, demonstrated geographical region wise trends of antibiotic resistance in S. aureus from India, which will be useful in designing the further studies investigating antibiotic resistance patterns.

Key Words: Staphylococcus aureus; Antibiotic resistance; Geography; India; β lactam

Core Tip: Staphylococcus aureus (S. aureus) antibiotic resistance reveals substantial regional heterogeneity across India, with significant variations in resistance rates even within the same geographical regions. This variance reflects variations in healthcare facilities, socioeconomic characteristics, and antibiotic usage behaviours. The results demonstrate the critical need for region-specific antibiotic stewardship programs and standardized, multicenter surveillance to direct efficient treatment and reduce the rising prevalence of multidrug-resistant S. aureus.

INTRODUCTION

The rapid emergence and spread of antibiotic resistance in pathogenic bacteria pose a major challenge to global health security[1]. Bacterial pathogens are implicated in a wide range of clinical and pathophysiological conditions, and the may cause diverse disease manifestations[2-6]. Many of these pathogens have acquired resistance to commonly used antibiotics, significantly limiting treatment options[7,8].

Furthermore, bacteria often coexist and interact within microbial communities, forming biofilms or producing toxins that enhance survival, virulence, and resistance to antimicrobial therapy[9,10]. Antibiotic resistance is closely linked to bacterial genetic composition[11], and the collective genetic repertoire of microbial communities can further influence resistance phenotypes[12,13]. Individual bacterial species may harbor multiple resistance mechanisms against a single drug, as demonstrated in Klebsiella pneumoniae, where mutations in two-component regulatory systems and efflux pump genes contribute to resistance[14]. Additionally, bacteria frequently employ distinct resistance mechanisms against different classes of antibiotics[15].

The continuous evolution of multidrug-resistant bacteria through novel resistance mechanisms underscores highlights the need for routine resistance surveillance[16]. The World Health Organization has identified six priority nosocomial pathogens, collectively termed ESKAPE: Enterococcus faecium, Staphylococcus aureus (S. aureus), Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. which are responsible for the majority of hospital-acquired infections and are particularly adept at evading antibiotic treatment[17,18]. Among these, S. aureus is the most prevalent Gram-positive pathogens worldwide, including in Asian countries[19,20].

S. aureus exhibits a broad spectrum of antibiotic resistance mechanisms, arising through chromosomal mutations as well as horizontal gene transfer via plasmids and transposons[21,22]. Methicillin resistance remains the most common and clinically significant form of resistance in S. aureus[23,24].

S. aureus is a common skin commensal but is also a major cause of wound infections and a wide range of nosocomial diseases, including osteoarticular infections, endocarditis, and soft tissue infections[25]. Importantly, antibiotic resistance patterns are influenced by social, economic, cultural, and healthcare-related factors, which vary considerably across regions[26]. India’s large population, diverse ethnic composition, varied healthcare infrastructure, and distinct biogeographic zones further contribute to regional heterogeneity in antimicrobial usage and resistance trends[27,28].

Given these factors, a consolidated and geographically informed assessment of antibiotic resistance in S. aureus within India is critically needed. An India-specific review can provide insights into regional resistance patterns, identify emerging trends, and highlight gaps in surveillance and antimicrobial stewardship. In this article, we systematically review published studies on antibiotic resistance in S. aureus from India, analyse resistance patterns across different geographic regions, and discuss the current status, challenges, and future perspectives for controlling S. aureus-associated antimicrobial resistance in the country.

MATERIALS AND METHODS

Study design

A protocol registration in International Prospective Register of Systematic Reviews has been done (Prospero registration No. PROSPERO 2025CRD420251153034). This study performed a systematic review for analysing antimicrobial resistance (AMR). We are adapting Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. For the present review, we searched for the studies describing the antibiotic resistance published from 2013 to 2024. As bacteria keep evolving resistance to antibiotics, the articles published from 2013 were considered. We systematically searched for the articles using databases including Scopus, Google scholar and PubMed.

Literature selection criteria

To identify publications for systematic reviews, these particular keywords were utilized in the relevant search engine: (“staphylococcus aureus” or “staphylococcus aureus bacteraemia” or “staph infection” or “staphylococcus aureus infection”) AND (“antimicrobial resistance” or “pathogen resistance” or “bacterial resistance” or “drug resistance” or “multi-drug resistance” or “resistant bacteria”) AND (“India” or “Indian”) AND (“prevalence” or “frequency” or “proportion” or “widespread”) AND (“2013:2024”). The searches obtained a total of 4640 documents from the aforementioned search engines. First, the downloaded research papers were verified to see whether they were duplicated, and 390 articles were omitted since they were found to be duplicates. The first screening began by reviewing each article's title and abstract. And 4124 of them were deleted this time since their titles and abstracts indicated that they did not support the overall purpose of the current study. According to the inclusion criteria, of the 126 literatures, 12 were review articles, 3 were case studies, and 8 were neonatal study or 23 were animal study, 2 were coagulase negative S. aureus or 1 were environmental study, 1 were no full text available and another 50 publications lack critical information on the technique of antibiotic resistance patterns. This review included only original research publications published in English. This leads to a total of 26 articles for to be assessed in this review. Figure 1 illustrates the process of selecting research publications using PRISMA principles.

Figure 1 Diagram illustrating the selection process of research articles using PRISMA. AMR: Analysing antimicrobial resistance; S. aureus: Staphylococcus aureus.

Quality assessment of included studies

To analyze the methodological quality of the included studies, we used the Newcastle-Ottawa Scale (NOS), which is commonly used to assess the quality of non-randomized studies, including observational studies such as cohort and case-control studies. Each research received a maximum of 9 ratings, divided as follows: Up to 4 stars for selection, 2 stars for comparability, and 3 stars for outcome/exposure. Star allocation was based on information available in the data extraction sheet, including study design, sample size, representativeness of isolates, and antimicrobial susceptibility testing methodology. Studies scoring 7-9 stars were considered high quality, 4-6 stars as moderate quality, and < 4 stars as low quality. Two independent reviewers performed the NOS scoring for each study. Two independent reviewers carried out the NOS scoring for each study. Disagreements in rating were resolved by discussion, and if a decision could not be reached, a third reviewer was involved.

Data extraction

Following the final selection of research papers based on the PRISMA standards, data from the various studies were retrieved. The data retrieved from the research papers include author’s names, the publication year, where the study was conducted, the study’s sample size, AMR, and the drugs that were used.

RESULTS

An exhaustive search yielded 4640 articles, which were then downloaded. Out of 4640 records, 402, 3529 and 709 were obtained from PubMed, Scopus and Google Scholar respectively. In accordance with the PRISMA, 26 records were used in this systematic review. Table 1[29-54] contains basic information about the included studies, such as the author's name, publication year, research site (Indian state), sample size, and the antibiotics examined in each study.

Table 1 Characteristics of included studies (2013–2024).

Ref.	Study design (observational/cohort/case control/cross sectional)	Study setting (state/region)	Sample size (n)	Clinical source (e.g., blood, wound, nasal swab)	Patient population	Laboratory methods	Antibiotics tested
[29]	Observational	Tamil Nadu, India	26	Sputum, nasal, throat swab	Patients from tertiary care hospital	Kirby-Bauer’s method/Kirby-Bauer disc diffusion method	Methicillin, ampicillin, penicillin, oflaxacin, oxacillin, tobramycin, gentamycin, vancomycin, ciprofloxacin, bacitracin, chloramphenico
[30]	Cohort	Odisha, India	718	Blood	People from rural community	Antimicrobial susceptibility disc diffusion method	Penicillin, ampicillin, erythromycin, azithromycin, cefoxitin, cotrimoxazole, clindamycin, teicoplanin, ciprofloxacin, vancomycin, chloramphenicol, levofloxacin, tetracycline, gentamicin, linezolid
[31]	Observational	Puducherry, India	8032	Blood, body fluids	People from rural and urban community	Kirby-Bauer’s method/Kirby-Bauer disc diffusion method	Penicillin, erythromycin, cefoxitin, cotrimoxazole, clindamycin, teicoplanin, ciprofloxacin, vancomycin, tetracycline, gentamicin, linezolid
[32]	Observational	Odisha, India	278	Pus, wound swab, nasal swab, skin swab, urine, body fluids and blood	Patients from tertiary care hospital	Cefoxitin disc diffusion test, D-test	Methicillin
[33]	Observational	India	185	Throat swab	Patients from tertiary care hospital	Antimicrobial susceptibility disc diffusion method	Erythromycin, penicillin, clindamycin, amoxicillin, gentamicin, vancomycin, tetracycline, ciprofloxacin
[34]	Observational	Delhi, India	6	Pus, wound	Patients from tertiary care hospital	Cefoxitin disc diffusion test, disc diffusion	Penicillin, amoxicillin methicillin, oxacillin, cefoxitin, gentamicin, ciprofloxacin, ceftazidime
[35]	Observational	Jaipur	30	Urine, inanimate swab, semen, earswabs, corneal swab	Patients from tertiary care hospital	Agar diffusion method	Ampicillin followed by ciprofloxacin, cotrimoxazole, cefixime, doxycycline/pefloxacin, ofloxacin, norfloxacin, cefuroxime, amoxiclave, cefazolin, cephalexin, amikacin, netilmicin
[36]	Cross-sectional observational	Haryana, India	747	Pus, exudates, wound, tissue, swab	Patients from tertiary care hospital	Antimicrobial susceptibility testing by VITEK 2 AST-P628 card (bioMerieuxInc., France)	Penicillin, gentamycin, co-trimoxazole, erythromycin, clindamycin, levofloxacin, tetracycline, linezolid, teicoplanin, vancomycin
[37]	Observational	Gujarat, India	36	Rectal swab, urine sample, wound swab, hand swab	Patients from tertiary care hospital	Disc diffusion testing	Penicillin, aziothromycin, erythromycin, linezolid, co-trimoxazole, vancomycin, cefoxitin, ciprofloxacin, gatifloxacon, ofloxacin, clindamycin, gentamycin, norfloxacin, ampicillin, piperacillin/tazobactum
[38]	Observational	Odisha, India	251	wound-swabs	Patients from tertiary care hospital	Disc diffusion testing	Amikacin, gentamycin, tobramycin, amoxyclav, ampicillin, oxacillin, piperacillin/tazobactam, cefepime, ceftazidime, ceftriaxone, gatifloxacin, levofloxacin, ciprofloxacin, ofloxacin, linezolid, vancomycin
[39]	Observational	Patna, India	86	Nasal swabs	Patients from tertiary care hospital	Disc diffusion testing	Methicillin
[40]	Cross-sectional	Mysore, India	200	Anterior nares and web spaces of both hands	Patients from tertiary care hospital	Disc diffusion testing	Methicillin
[41]	Observational cross-sectional	Kashmir, India	229	Nasal swabs	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Erythromycin, clindamycin, vancomycin, tetracycline, co-trimoxazole, gentamicin, penicillin, ciprofloxacin, cefoxitin, oxacillin
[42]	Cross-sectional	Kolkata, West Bengal, India	46	23 pus, 6 blood, 17 wound swab	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Cefoxitin, clindamycin, azithromycin, erythromycin, co-trimoxazole, ciprofloxacin, vancomycin, linezolid
[43]	Retrospective study	India	26310	Pus, blood, respiratory samples, urine, sterile body fluids, tissue, ear swab, nasa swab, skin swab	Patients from tertiary care Hospital	Kirby-Bauer disc diffusion	Erythromycin, clindamycin, co-trimoxazole, gentamicin, penicillin, ciprofloxacin
[44]	Cross-sectional study	Pondicherry, India	192	Pus swab	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Methicillin
[45]	Cross sectional	South India	102	Pus swab	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Ciprofloxacin, tetracycline, gentamicin, amikacin, netilmicin, co-trimoxazole, chloramphenicol
[46]	Observational, cross-sectional	Mumbai/Pune India	143	Pus, urine, blood and sputum samples, pleural fluids and tissue bits	Patients from tertiary care hospital	Disc difusion method	Erythromycin, ciprofloxacin, trimethoprimsulfamethoxazole, gentamicin, tetracycline
[47]	Observational, cross-sectional	Karad, India	100	Pus, sputum, wound swabs, blood, urine, and other body fluids	Patients from tertiary care hospital	Disc difusion method	Penicillin-G, erythromycin, gentamycin, co-trimoxazole, clindamycin, levofloxacin, ciprofloxaci, amikacin, nitrofurantoin, linezolid, vancomycin
[48]	Observational	Kolkata, India	50	Wound	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Amoxyclav, erythromycin, ciprofloxacin, levofloxacin, cefuroxime, clindamycin, gentamicin, trimethoprim– sulfamethoxazole, amikacin, doxycycline
[49]	Observational	Punjab, India	248	Pus, blood, urine, body fluids, catheter tips etc.	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Erythromycin, clindamycin, gentamicin, ciprofloxacin, vancomycin, linezolid, Ampicillin, co-trimoxazole
[50]	Observational, cross-sectional	South, India	100	Skin swab	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Gentamicin, erythromycin, clindamycin, tetracycline, ciprofloxacin
[51]	Observational	Tamil Nadu, India	165	Throat swab	Patients from tertiary care hospital	Kirby-Bauer disc diffusion	Pethicillin
[52]	Observational	Haryana, India	104	Blood culture bottles	Patients from tertiary care hospital	Cefoxitin disc diffusion test, Kirby-Bauer disc diffusion	Penicillin, erythromycin, clindamycin, gentamicin, ciprofloxacin, cotrimoxazole
[53]	Prospective, cross sectional study	Patna, India	179	Pus, urine, blood, conjunctival swab, endo-tracheal aspirate and synovial fluid	Patients from tertiary care Hospital	Cefoxitin disc diffusion test, Kirby-Bauer disc diffusion	Penicillin, erythromycin, clindamycin, ciprofloxacin, gentamicin, cotrimoxazole, vancomycin, linezolid
[54]	Observational	Doon Valley, Uttrakhand	111	Nasal swab	Patients from tertiary care hospital	Cefoxitin disc diffusion test, Kirby-Bauer disc diffusion	Methicillin

We assessed the quality of included study using NOS shown in Table 2[29-54]. Out of 26 studies, 3 studies were classified as high quality (NOS ≥ 7), while the remaining 22 studies were of moderate quality (NOS 4-6) and 1 study was of low quality (NOS < 4). No study was excluded on the basis of quality assessment. In cases of incomplete reporting, conservative scoring was applied.

Table 2 Quality assessment of included studies using the Newcastle–Ottawa Scale.

Ref.	Quality rating (high/moderate/low)
[29]	Moderate
[30]	Moderate
[31]	High
[32]	Moderate
[33]	Moderate
[34]	Low
[35]	Moderate
[36]	Moderate
[37]	Moderate
[38]	Moderate
[39]	Moderate
[40]	Moderate
[41]	Moderate
[42]	Moderate
[43]	High
[44]	Moderate
[45]	Moderate
[46]	Moderate
[47]	Moderate
[48]	Moderate
[49]	Moderate
[50]	Moderate
[51]	Moderate
[52]	Moderate
[53]	High
[54]	Moderate

Antibiotic resistance trend in S. aureus

Among 26 studies, most of the studies were reported from northern India (31%), southern India (27%) and eastern India (27%), followed by western India (11%) and Pan India (4%) (Figure 2). This distribution highlights regional variability and under-representation of certain geographical areas in antimicrobial resistance surveillance. In this systematic review to assess the antimicrobial resistance pattern of S. aureus. Resistance data were available for antibiotics belonging to multiple therapeutic classes, showing wide variation across drugs (Figure 3 and Table 3).

Figure 2 Geographical region wise distribution of the studies (n = 26) in India reported (during 2013 to 2024) on the antibiotic resistance in Staphylococcus aureus.

Figure 3 Balloon plot depicting the antibiotic resistance patterns in Staphylococcus aureus to different drugs. Percentage of resistant to different drugs was plotted in different studies (published during 2013 to 2024) in India.

Table 3 Antibiotics reported in 26 studies and their classes.

Class of antibiotics	Name of antibiotic	No of studies	Mean	Min	Max
Beta lactam	Penicillin	12	91.77	59.25	100.00
	Amoxicillin	6	75.71	17.64	100.00
	Ampicillin	7	69.85	28.00	100.00
	Cephalexin	1	17.64	17.64	17.64
	Cefazolin	1	17.64	17.64	17.64
	Ceftriaxone	1	6.00	6.00	6.00
	Cefuroxime	2	12.32	7.00	17.64
	Meropenem	0	0.00	0.00	0.00
	Imepenem	0	0.00	0.00	0.00
	Augmentin	0	0.00	0.00	0.00
	Cefoxitin	6	37.53	6.55	83.30
	Cefepime	1	67.25	67.25	67.25
	Methicillin	9	53.96	3.48	100.00
	Piperacillin	2	54.13	36.00	72.25
	Ceftazidime	2	62.98	59.25	66.70
	Cloxacillin	1	52.94	52.94	52.94
	Cefixime	0	0.00	0.00	0.00
	Cephalosporin	0		0.00	0.00
	Oxacillin	5	48.54	4.00	93.33
	Cefotaxime	0	0.00	0.00	0.00
Glycopeptides	Vancomycin	6	46.20	7.00	100.00
	Teicoplanin	3	5.52	0.10	15.00
Tetracycline	Tetracycline	9	32.22	4.80	66.60
	Doxycycline	2	26.59	12.00	41.17
	Minocycline	0		0.00	0.00
Lincosamide	Clindamycin	15	42.58	8.73	91.48
Macrolides	Erythromycin	12	63.62	9.17	100.00
	Azithromycin	4	30.56	8.00	71.00
Fluroquinolones	Ciprofloxacin	16	54.88	6.38	89.20
	Levofloxacin	4	59.63	8.00	86.00
	Ofloxacin	5	67.95	35.29	100.00
	Gatifloxain	2	64.25	52.00	76.50
	Fluoroquinolones	0	0.00	0.00	0.00
	Norfloxacin	2	30.71	29.41	32.00
Aminoglycosides	Netilmycin	2	11.85	6.05	17.64
	Streptomycin	0	0.00	0.00	0.00
	Gentamycin	17	46.76	3.00	86.00
	Amikacin	4	33.94	17.64	73.25
	Tobramycin	2	66.75	47.50	86.00
Rifamycins	Rifampicin	0		0.00	0.00
Oxazolidinones	Linezolid	4	19.60	2.90	37.50
Synthetic	Cotrimoxazole	16	48.46	20.00	81.45
Nitrobenzene ring	Chloramphenicol	3	18.12	8.00	34.10
Lipopeptide	Daptomycin	0	0.00	0.00	0.00
Phosphonic acid	Fosfomycin	0	0.00	0.00	0.00

Number of studies represent the number of research articles (published during 2013 to 2024) reporting resistance in Staphylococcus aureus to the particular drug.

Beta-lactam antibiotics

High resistance was observed against beta-lactam antibiotics. Penicillin showed the highest resistance, with a mean value of 91.77%, indicating poor effectiveness. Substantial resistance was also reported for amoxicillin and ampicillin. Resistance to methicillin was documented in nine studies, with an average resistance of 53.96%, suggesting a high prevalence of methicillin-resistant S. aureus (MRSA). Cephalosporins demonstrated different resistance patterns, where resistance levels were higher for cefepime, ceftazidime, and cefoxitin, resistance levels were lower for ceftriaxone and cefuroxime. There was no report on the use of carbapenems and beta, lactam/beta, lactamase inhibitor combinations.

Glycopeptides

Resistance to vancomycin was reported in six studies and varied widely, indicating reduced susceptibility in some settings. In contrast, teicoplanin showed consistently low resistance, suggesting preserved activity.

Tetracyclines

Moderate resistance was noted for tetracycline, while doxycycline showed comparatively lower resistance. No data were available for minocycline.

Lincosamides and macrolides

Clindamycin demonstrated moderate resistance, with wide variation across studies. Among macrolides, erythromycin showed high resistance, whereas azithromycin displayed lower and variable resistance.

Fluoroquinolones

High resistance was commonly observed among fluoroquinolones. Ofloxacin, gatifloxacin, levofloxacin, and ciprofloxacin all demonstrated elevated resistance levels, indicating reduced effectiveness of this class.

Aminoglycosides

Among aminoglycosides, gentamicin was the most frequently reported and showed moderate resistance. Higher resistance was seen with tobramycin, while amikacin and netilmicin showed lower resistance levels.

Other antibiotics

Resistance to cotrimoxazole was moderate across studies. Linezolid showed low resistance, indicating maintained efficacy. Chloramphenicol also demonstrated low resistance. No resistance data were available for rifampicin, daptomycin, or fosfomycin.

Overall, the review indicates high resistance to commonly used antibiotics, particularly beta-lactams and fluoroquinolones. In contrast, linezolid, teicoplanin, doxycycline, and chloramphenicol retained better activity against S. aureus. These findings highlight the importance of continuous resistance monitoring and rational antibiotic use.

DISCUSSION

The findings of the present study reaffirm that S. aureus, particularly methicillin-resistant strains, continues to represent a major infectious threat in Indian healthcare settings. Despite advances in diagnostics and antimicrobial therapy, MRSA remains widely prevalent and exhibits resistance to multiple antibiotic classes, limiting effective treatment options. Similar concerns have been raised at the national level, where systematic analyses have highlighted the sustained burden and clinical impact of MRSA infections across India[55].

The resistance patterns observed in our study are broadly consistent with multicentric surveillance reports generated by the Indian Council of Medical Research antimicrobial resistance surveillance network. These studies have documented high resistance rates among Staphylococcus species, with notable geographic and institutional variability[31]. Such heterogeneity suggests that local antimicrobial usage practices and infection control measures significantly influence resistance trends. The continued circulation of resistant strains underscores the importance of region-specific surveillance rather than reliance on pooled national estimates alone.

High resistance to commonly used β-lactam antibiotics observed in our study aligns with earlier hospital-based investigations conducted in different parts of India. Studies from tertiary care centres have consistently reported reduced susceptibility of S. aureus to penicillin, ampicillin, and other first-line agents, reflecting long-standing selective pressure[56,57]. Of particular concern is the gradual increase in minimum inhibitory concentrations reported for last-resort antibiotics, a phenomenon described as minimum inhibitory concentration creep, which has been previously noted in Indian clinical isolates[57]. Although complete resistance to glycopeptides remains uncommon, the emergence of vancomycin-intermediate strains reported from southern India signals a worrying trend[51].

Macrolide and lincosamide resistance patterns in the present study also mirror observations from earlier Indian studies. Inducible clindamycin resistance has been widely reported and is clinically significant, as failure to detect this phenotype may lead to inappropriate therapy and treatment failure[32,42]. Molecular investigations have further demonstrated the presence of erythromycin resistance determinants among Indian S. aureus isolates, supporting the phenotypic resistance observed in routine laboratory testing[33]. These findings emphasize the need for routine implementation of confirmatory tests for inducible resistance in clinical microbiology laboratories.

The increasing recognition of community-associated MRSA in India is another important aspect highlighted by our findings. Several studies have reported MRSA infections in patients without traditional healthcare exposure, including cases of skin and soft tissue infections, nasal carriage among healthy individuals, and pyoderma[41,50]. Our results are in agreement with these observations and suggest that MRSA is no longer confined to hospital environments. The detection of virulence-associated markers, such as Panton-Valentine leukocidin genes, further complicates the clinical profile of community-associated strains and may contribute to disease severity[50].

Severe and invasive infections caused by multidrug-resistant S. aureus, including ventilator-associated pneumonia, bloodstream infections, and central nervous system infections, have been frequently reported from Indian tertiary care hospitals[31,57,58]. Similar clinical implications were evident in our study population, highlighting the increased risk of adverse outcomes in patients infected with resistant strains. Genetic studies have shown that resistance in MRSA is often mediated by mobile genetic elements, including integrons, which facilitate rapid dissemination of resistance determinants within hospital settings[46].

From a broader public health perspective, the findings of this study are particularly relevant in the context of India’s National Action Plan on Antimicrobial Resistance. Although policy frameworks and surveillance mechanisms are in place, gaps in implementation and regional data generation remain evident[59,60]. Institution-based studies such as ours therefore play a crucial role in supplementing national surveillance data and informing local antimicrobial stewardship strategies.

In summary, the resistance patterns observed in this study closely parallel those reported in earlier Indian literature, reinforcing the persistent and evolving challenge posed by MRSA. The convergence of hospital-associated and community-associated strains, coupled with rising multidrug resistance, highlights the urgent need for continuous surveillance, rational antibiotic use, and strengthened infection control practices to limit further spread of resistant S. aureus in India.

CONCLUSION

This systematic review shows that S. aureus has developed widespread antimicrobial resistance across India, particularly to commonly prescribed antibiotics. The persistently high burden of MRSA highlights the urgent need for stricter infection control and more rational antibiotic use in clinical practice. Empirical treatment guidelines should be regularly updated based on local resistance data, and antibiotics with lower resistance should be used cautiously under antimicrobial stewardship programs. For future research, continuous regional surveillance, standardized susceptibility testing, and molecular studies on resistance mechanisms are essential to monitor trends, guide therapy, and develop effective strategies to limit further resistance.

ACKNOWLEDGEMENTS

The authors are grateful to Dr. D. Y. Patil Medical College, Hospital and Research Centre and Dr. D. Y. Patil Vidyapeeth, Pune, for providing necessary facility and support.