Date of Publication
11-2025
Document Type
Master's Thesis
Degree Name
Master of Science in Biology
Subject Categories
Biology
College
College of Science
Department/Unit
Biology
Thesis Advisor
Llewelyn Moron Espiritu
Mark Angelo O. Balendres
Defense Panel Chair
Florabelle D. Querubin
Defense Panel Member
Anish M.S. Shrestha
Ronilo Jose Flores
Abstract (English)
Antimicrobial resistance (AMR) is one of the most pressing global health threats. In 2019, an estimated 1.27 million deaths were directly attributed to bacterial AMR and 4.9 million deaths associated with it. Hospital wastewater (HWW) harbors antibiotic resistance genes (ARG) and a diversity of antibiotic-resistant bacteria (ARB), which contribute to the AMR problem. This study profiled the ARGs, ARBs, and mobile genetic elements (MGE) of untreated hospital wastewater from three tertiary hospitals in Metro Manila using shotgun metagenomic sequencing. Results revealed high abundances of ARGs conferring resistance to sulfonamides (sul1, sul2), aminoglycosides (aadS), and macrolides/streptogramins (msrE, mphE). Notably, antiseptic and disinfectant resistance genes (qacEΔ1, qacL) were detected for the first time in Philippine HWWs. A significantly higher diversity (Shannon) of ARGs was seen in HWW B and HWW C against HWW A (p < 0.01). The bacterial community was dominated by Pseudomonadota, with prevalent genera including Stenotrophomonas, Pseudomonas, and Rhodococcus. There was no significant difference in biodiversity (Shannon index) of the genera found across the hospitals (p > 0.05). A wide diversity of MGEs associated with resistance to multiple drug classes, including antiseptics and disinfectants, was observed. These included insertion sequences (IS1071, ISPasp1, IS1247, ISVsa3, ISAba1, ISStma11), Class 1 integrons, and plasmid replicons (IncQ2, IncP6, repUS43, Col440II, Col(pHAD28), and ColRNAI). Overall, these findings highlight key ARGs, bacterial pathogens, and MGEs that may contribute to the persistence and transmission of AMR within healthcare settings, underscoring the value of integrating genotypic surveillance of HWW into existing AMR surveillance to guide wastewater management and strengthen infection control measures.
Abstract Format
html
Abstract (Filipino)
Ang antimicrobial resistance (AMR) ay isa sa mga pinakamalaking banta sa pandaigdigang kalusugan. Noong 2019, tinatayang 1.27 milyong pagkamatay ang direktang iniuugnay sa bacterial AMR at 4.9 milyong pagkamatay ang may kaugnayan dito. Ang wastewater mula sa mga ospital (HWW) ay naglalaman ng antibiotic resistance genes (ARG) at iba’t ibang uri ng antibiotic-resistant bacteria (ARB) na dumadagdag sa problema ng AMR. Sinuri sa pag-aaral na ito, ang mga ARG, ARB, at mobile genetic elements (MGE) sa HWW mula sa tatlong tersiyaryong ospital sa Metro Manila gamit ang shotgun metagenomic sequencing. Ipinakita ng mga resulta ang mataas na bilang ng ARG na nagbibigay ng resistansya sa sulfonamides (sul1, sul2), aminoglycosides (aadS), at macrolides/streptogramins (msrE, mphE). Kapansin-pansin, ang mga gene para sa resistansya sa antiseptics at disinfectants (qacEΔ1, qacL) ay natukoy sa kauna-unahang pagkakataon sa HWW sa Pilipinas. Mas mataas na pagkakaiba-iba (Shannon) ng ARG ang nakita sa HWW B at HWW C kumpara sa HWW A (p < 0.01). Ang komunidad ng bakterya ay pinamunuan ng Pseudomonadota, kung saan karaniwang matatagpuan ang mga genus na Stenotrophomonas, Pseudomonas, at Rhodococcus. Walang makabuluhang pagkakaiba sa biodiversity (Shannon index) ng mga genus na natagpuan sa mga ospital (p > 0.05). Nakita rin ang malawak na pagkakaiba-iba ng mga MGEs na may kaugnayan sa resistansya sa iba’t ibang klase ng gamot, kabilang ang antiseptics at disinfectants. Kabilang dito ang insertion sequences (IS1071, ISPasp1, IS1247, ISVsa3, ISAba1, ISStma11), Class 1 integrons, at plasmid replicons (IncQ2, IncP6, repUS43, Col440II, Col(pHAD28), at ColRNAI). Sa kabuuan, itinatampok ng mga natuklasan ang mahahalagang ARG, bacterial pathogens, at MGE na maaaring mag-ambag sa pagpapatuloy at pagkalat ng AMR sa mga pasilidad pangkalusugan. Binibigyang-diin nito ang kahalagahan ng pag-integrate ng genotypic surveillance ng HWW sa umiiral na AMR surveillance upang makatulong sa mas mahusay na pamamahala ng HWW at pagpapatibay ng infection control measures.
Abstract Format
html
Language
English
Format
Electronic
Keywords
Metagenomics; Drug resistance in icroorganisms; Bioinformatics; Sewage--Philippines--Metro Manila
Recommended Citation
Santos, J. E. (2025). The resistome, bacterial composition, and mobilome of hospital wastewaters in Metro Manila: A shotgun metagenomics approach. Retrieved from https://animorepository.dlsu.edu.ph/etdm_bio/33
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Embargo Period
12-4-2026
