Hospital-Associated Synanthropic Insects as Carriers of Methicillin-Resistant Staphylococcus aureus: Evidence from Lahore, Pakistan: Hospital-Associated Synanthropic Carriers of Methicillin-Resistant Staphylococcus aureus

Taskeen Zahra; Hafiza Amina Rafiq; Marvah Qiass; . Mehwish; Saba Riaz

doi:10.54393/fbt.v5i3.196

Authors

Taskeen Zahra Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
Hafiza Amina Rafiq Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
Marvah Qiass Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
. Mehwish Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan
Saba Riaz Institute of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan

DOI:

https://doi.org/10.54393/fbt.v5i3.196

Keywords:

Methicillin-Resistant Staphylococcus Aureus, Houseflies, Garlic Extract, Antimicrobial Resistance

Abstract

The issue of antimicrobial resistance (AMR) is significant in the world, and one of the most important types of pathogens that transmit both nosocomial and community infections is methicillin-resistant Staphylococcus aureus (MRSA). Objectives: To determine the existence of antibiotic-resistant Gram-positive bacteria in hospital-related insects, to describe the resistance mechanisms and biofilm-forming capabilities of the bacteria. Methods: Two hundred houseflies were taken from one hospital, which was a tertiary care hospital in Lahore. The isolates of S. aureus were determined by mannitol fermentation, Gram stain, and standard biochemical assays. The Kirby-Bauer disk diffusion method of performing antimicrobial susceptibility testing was conducted as per CLSI (2023) guidelines. A microtiter plate assay was used to determine biofilm formation. PCR detection of the mecA and mecC genes was done by extracting their genomic DNA. The agar well diffusion assay was employed to determine the activity of FGE as a single entity and in conjunction with the 3-lactam antibiotics. Results: Sixteen S. aureus isolates (8% of the flies) were recovered. All isolates were methicillin-resistant and carried the mecA gene, while the mecC gene was absent. Resistance was universal to oxacillin (100%) and nitrofurantoin (100%), and was high against erythromycin (87.5%) and rifampicin (75%). Most isolates (62.5%) were strong biofilm producers. Conclusions: Hospital-associated houseflies can serve as reservoirs and potential vectors for multidrug-resistant, biofilm-forming MRSA. The synergy observed between FGE and β-lactam antibiotics highlights the potential of plant-derived adjuncts in addressing resistant infections.

References

Salam MA, Al-Amin MY, Salam MT, Pawar JS, Akhter N, Rabaan AA et al. Antimicrobial Resistance: A Growing Serious Threat for Global Public Health. In Healthcare. 2023 Jul; 11(13):1946. doi: 10.3390/healthcare11131946.

Safdar N, Saleem S, Salman M, Tareq AH, Ishaq S, Ambreen S et al. Economic Burden of Antimicrobial Resistance on Patients in Pakistan. Frontiers in Public Health. 2025 Feb; 13: 1481212. doi: 10.3389/fpubh.2025.1481212.

Naghavi M, Vollset SE, Ikuta KS, Swetschinski LR, Gray AP, Wool EE et al. Global Burden of Bacterial Antimicrobial Resistance 1990–2021: A Systematic Analysis with Forecasts to 2050. The Lancet. 2024 Sep; 404(10459): 1199-226.

Abebe AA and Birhanu AG. Methicillin-Resistant Staphylococcus Aureus: Molecular Mechanisms Underlying Drug Resistance Development and Novel Strategies to Combat. Infection and Drug Resistance. 2023 Dec: 7641-62. doi: 10.2147/IDR.S428103.

Lade H and Kim JS. Molecular Determinants of Β-Lactam Resistance in Methicillin-Resistant Staphylococcus Aureus (MRSA): An Updated Review. Antibiotics. 2023 Aug; 12(9): 1362. doi: 10.3390/antibiotics12091362

Brakstad OG, and Mæland JO. Mechanisms of Methicillin Resistance in Staphylococci. Journal of Pathology, Microbiology and Immunology. 1997 Jan; 105(1‐6): 264-76. doi: 10.1111/j.1699-0463.1997.tb00568.x.

Khan AA, Ali A, Tharmalingam N, Mylonakis E, Zahra R. First Report of mecC Gene in Clinical Methicillin-Resistant S. Aureus (MRSA) from Tertiary Care Hospital Islamabad, Pakistan. Journal of Infection and Public Health. 2020 Oct; 13(10): 1501-7. doi: 10.1016/j.jiph.2020.05.017.

Gwenzi W, Chaukura N, Muisa-Zikali N, Teta C, Musvuugwa T, Rzymski P et al. Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance. Antibiotics. 2021 Jan; 10(1): 68. doi: 10.3390/antibiotics10010068.

Silva V, Almeida L, Gaio V, Cerca N, Manageiro V, Caniça M et al. Biofilm Formation of Multidrug-Resistant MRSA Strains Isolated from Different Types of Human Infections. Pathogens. 2021 Jul; 10(8): 970. doi: 0.3390/pathogens10080970.

Murugaiyan J, Kumar PA, Rao GS, Iskandar K, Hawser S, Hays JP et al. Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics. Antibiotics. 2022 Feb; 11(2): 200. doi: 10.3390/antibiotics11020200.

Iskandar K, Hawser S, Hays JP, Mohsen Y, Adukkadukkam S, Awuah WA et al. Progress in Alternative Strategies to Combat Antimicrobial Resistance: Focus on Antibiotics. Antibiotics. 2022; 11: 200. doi: 10.3390/antibiotics11020200.

Stepanović S, Vuković D, Hola V, Bonaventura GD, Djukić S, Ćirković I et al. Quantification of Biofilm in Microtiter Plates: Overview of Testing Conditions and Practical Recommendations for Assessment of Biofilm Production by Staphylococci. Journal of Pathology, Microbiology and Immunology. 2007 Aug; 115(8):891-9. doi: 10.1111/j.1600-0463.2007.apm_630.x.

Yılmaz EŞ and Aslantaş Ö. Antimicrobial Resistance and Underlying Mechanisms in Staphylococcus Aureus Isolates. Asian Pacific Journal of Tropical Medicine. 2017 Nov; 10(11): 1059-64. doi: 10.1016/j.apjtm.2017.10.003.

Ezeh CK, Eze CN, Dibua ME, Emencheta SC. A Meta-Analysis on the Prevalence of Resistance of Staphylococcus Aureus to Different Antibiotics in Nigeria. Antimicrobial Resistance & Infection Control. 2023 Apr; 12(1): 40. doi: 10.1186/s13756-023-01243-x.

Idrees MM, Saeed K, Shahid MA, Akhtar M, Qammar K, Hassan J et al. Prevalence of mecA-and mecC-associated Methicillin-Resistant Staphylococcus Aureus in Clinical Specimens, Punjab, Pakistan. Biomedicines. 2023 Mar; 11(3): 878. doi: 10.3390/biomedicines11030878.

Lozano C, Fernández-Fernández R, Ruiz-Ripa L, Gómez P, Zarazaga M, Torres C. Human mecC-Carrying MRSA: Clinical Implications and Risk Factors. Microorganisms. 2020 Oct; 8(10): 1615. doi: 10.3390/microorganisms8101615.

Yin JH, Kelly PJ, Wang C. Flies as Vectors and Potential Sentinels for Bacterial Pathogens and Antimicrobial Resistance: A Review. Veterinary Sciences. 2022 Jun; 9(6): 300. doi: 10.3390/vetsci9060300.

Cook K, Premchand-Branker S, Nieto-Rosado M, Portal EA, Li M, Rubio CO et al. Flies as Carriers of Antimicrobial Resistant (AMR) Bacteria in Nigerian Hospitals: A Workflow for Surveillance of AMR Bacteria Carried by Arthropod Pests in Hospital Settings. Environment International. 2025 Feb; 196: 109294. doi: 10.1016/j.envint.2025.109294.

Awan AB, Arshad MM, Haque A. Level of Biofilm Production by Staphylococcus Aureus Isolates Is Critical for Resistance Against Most but Not All Antimicrobial Drugs. Pakistan Journal of Medical Sciences. 2022 Nov; 38(8): 2150. doi: 10.12669/pjms.38.8.6276.

Li G, Ma X, Deng L, Zhao X, Wei Y, Gao Z et al. Fresh Garlic Extract Enhances the Antimicrobial Activities of Antibiotics on Resistant Strains in Vitro. Jundishapur journal of microbiology. 2015 May; 8(5): e14814. doi: 10.5812/jjm.14814.