Genomic Epidemiology and Genetic Relatedness of Antimicrobial-Resistant Morganella morganii in Community and Hospital Settings in Bangladesh
- 1ICDDRB: International Centre for Diarrhoeal Disease Research Bangladesh
Abstract
Morganella morganii is an opportunistic pathogen with intrinsic and acquired antimicrobial resistance, but its genomic epidemiology remains poorly characterized in Bangladesh. We sequenced and compared genomes of 47 stool-derived M. morganii isolates from hospital (n = 29) and community (n = 18) participants in urban Dhaka.
Susceptibility testing showed frequent resistance to imipenem (70{middle dot}2%) and cefuroxime (97{middle dot}9%), while all isolates were resistant to colistin. Resistance to meropenem (6{middle dot}4%) and ertapenem (2{middle dot}1%) was uncommon. Based on acquired non-susceptibility across tested antimicrobial categories, 18/47 (38{middle dot}3%) isolates were multidrug-resistant, including 15/29 (51{middle dot}7%) hospital-derived and 3/18 (16{middle dot}7%) community-derived isolates. Genomic analysis identified 17 {beta}-lactamase alleles including Morganella-associated chromosomal {beta}-lactamases and acquired resistance determinants, with blaOXA-1, blaDHA-21, blaCTX-M-15, and blaTEM-1 predominating. However, no recognized acquired carbapenemase genes were detected. Among 44 non-{beta}-lactam resistance genes, tetB was most frequent.
Phylogenomic and average nucleotide identity analyses classified 31 isolates as M. morganii subsp. morganii and 16 as the subsp. intermedius lineage. Considerable population diversity was observed, with 33 distinct sequence types among the 47 isolates and no clear clustering by hospital or community origin. The subsp. intermedius isolates showed greater genomic heterogeneity than subsp. morganii, with a minimum within-group average nucleotide identity of 94{middle dot}2%. Single nucleotide variant (SNV) analysis identified several closely related isolate groups, including an ST1 pair differing by 10 SNVs and collected three days apart within the same hospital, although direct transmission could not be established.
Virulence-associated gene profiles differed between subspecies, with hemolysin- and toxin-associated genes predominantly detected among subsp. morganii isolates and largely absent from subsp. intermedius. Overall, these findings reveal substantial genomic diversity, a considerable burden of multidrug resistance, and subspecies-associated differences in virulence gene content among M. morganii circulating in Dhaka, while the frequent imipenem-non-susceptible but carbapenemase-negative phenotype highlights the need to investigate alternative carbapenem resistance mechanisms.
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BibTeX
@misc{rahman2026genomic,
title = {{Genomic Epidemiology and Genetic Relatedness of Antimicrobial-Resistant Morganella morganii in Community and Hospital Settings in Bangladesh}},
author = {T. Rahman and T. Khan and A. Haider and S. B. Moon and N. S. N. Samia and S. Mah-E-Muneer and G. M. S. Mamun and F. Chowdhury and M. Rahman and M. Jubair},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.23.26363554},
url = {https://www.medrxiv.org/content/10.64898/2026.09.23.26363554v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Genomic Epidemiology and Genetic Relatedness of Antimicrobial-Resistant Morganella morganii in Community and Hospital Settings in Bangladesh
AU - T. Rahman
AU - T. Khan
AU - A. Haider
AU - S. B. Moon
AU - N. S. N. Samia
AU - S. Mah-E-Muneer
AU - G. M. S. Mamun
AU - F. Chowdhury
AU - M. Rahman
AU - M. Jubair
PY - 2026
DA - 2026/09/23
PB - medRxiv
DO - 10.64898/2026.09.23.26363554
UR - https://www.medrxiv.org/content/10.64898/2026.09.23.26363554v1
AB - Morganella morganii is an opportunistic pathogen with intrinsic and acquired antimicrobial resistance, but its genomic epidemiology remains poorly characterized in Bangladesh. We sequenced and compared genomes of 47 stool-derived M. morganii isolates from hospital (n = 29) and community (n = 18) participants in urban Dhaka. Susceptibility testing showed frequent resistance to imipenem (70{middle dot}2%) and cefuroxime (97{middle dot}9%), while all isolates were resistant to colistin. Resistance to meropenem (6{middle dot}4%) and ertapenem (2{middle dot}1%) was uncommon. Based on acquired non-susceptibility across tested antimicrobial categories, 18/47 (38{middle dot}3%) isolates were multidrug-resistant, including 15/29 (51{middle dot}7%) hospital-derived and 3/18 (16{middle dot}7%) community-derived isolates. Genomic analysis identified 17 {beta}-lactamase alleles including Morganella-associated chromosomal {beta}-lactamases and acquired resistance determinants, with blaOXA-1, blaDHA-21, blaCTX-M-15, and blaTEM-1 predominating. However, no recognized acquired carbapenemase genes were detected. Among 44 non-{beta}-lactam resistance genes, tetB was most frequent. Phylogenomic and average nucleotide identity analyses classified 31 isolates as M. morganii subsp. morganii and 16 as the subsp. intermedius lineage. Considerable population diversity was observed, with 33 distinct sequence types among the 47 isolates and no clear clustering by hospital or community origin. The subsp. intermedius isolates showed greater genomic heterogeneity than subsp. morganii, with a minimum within-group average nucleotide identity of 94{middle dot}2%. Single nucleotide variant (SNV) analysis identified several closely related isolate groups, including an ST1 pair differing by 10 SNVs and collected three days apart within the same hospital, although direct transmission could not be established. Virulence-associated gene profiles differed between subspecies, with hemolysin- and toxin-associated genes predominantly detected among subsp. morganii isolates and largely absent from subsp. intermedius. Overall, these findings reveal substantial genomic diversity, a considerable burden of multidrug resistance, and subspecies-associated differences in virulence gene content among M. morganii circulating in Dhaka, while the frequent imipenem-non-susceptible but carbapenemase-negative phenotype highlights the need to investigate alternative carbapenem resistance mechanisms.
ER -