Prevalence and Identification of Enterobacter cloacae from Clinical Samples in Thi-Qar
DOI:
https://doi.org/10.32792/utq/utjsci/v12i2.1407Keywords:
E. cloacae, Clinical Samples, EnterobacteriaceaeAbstract
Enterobacter cloacae is an opportunistic pathogen frequently associated with a wide range of clinical infections. Given the increasing prevalence of this bacterium and the limited information available on its virulence factors in Iraq, further investigation is warranted. This study aimed to analyze various clinical samples, accurately identify the presence of E. cloacae using diverse analytical methods, and confirm the findings through advanced diagnostic systems. A total of 200 clinical specimens were collected from hospitals and diagnostic laboratories in Thi-Qar province. Bacterial identification was carried out using morphological and biochemical methods, as well as automated systems such as API 20E and VITEK-2. Out of the 200 samples, 30 (15%) were confirmed to be E. cloacae. The prevalence showed no significant gender difference, with equal distribution between males and females (50% each). The highest infection rate (40%) was observed in the 20–30-year age group. Blood and wound specimens exhibited the highest isolation rate (33.33%), while stool samples showed the lowest (10%). This study emphasizes the clinical relevance of E. cloacae infections in Thi-Qar, particularly among younger individuals and patients presenting with blood or wound infections. The use of automated diagnostic tools proved essential for accurate bacterial identification.
Received: 2025-05-20
Revised: 2025-06-28
Accepted: 2025-07-12
References
B. J. Tindall, G. Sutton, and G. M. Garrity, “Enterobacter aerogenes Hormaeche and Edwards 1960 (Approved Lists 1980) and Klebsiella mobilis Bascomb et al. 1971 (Approved Lists 1980) share the same nomenclatural type (ATCC 13048) on the Approved Lists and are homotypic synonyms, with consequences for the name Klebsiella mobilis Bascomb et al. 1971 (Approved Lists 1980),” INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, vol. 67, no. 2, pp. 502–504, Oct. 2016, https:// doi. org/ 10. 1099/ ijsem.0. 001572.
W. Wu, Y. Feng, and Z. Zong, “Precise Species Identification for Enterobacter : a Genome Sequence-Based Study with Reporting of Two Novel Species, Enterobacter quasiroggenkampii sp. nov. and Enterobacter quasimori sp. nov,” mSystems, vol. 5, no. 4, Aug. 2020, https:// doi. org/ 10. 1128/ mSyst ems. 00527- 20.
A. Davin-Regli, J.-P. Lavigne, and J.-M. Pagès, “Enterobacter spp.: Update on Taxonomy, Clinical Aspects, and Emerging Antimicrobial Resistance,” Clinical Microbiology Reviews, vol. 32, no. 4, Jul. 2019, https:// doi. org/ 10. 1128/ CMR. 00002- 19.
G. Mancuso, A. Midiri, E. Gerace, and C. Biondo, “Bacterial antibiotic resistance: the most critical pathogens,” Pathogens, vol. 10, no. 10, p. 1310, Oct. 2021, https:// doi. org/ 10. 3390/ patho gens1 01013 10.
A. Davin-Regli and J.-M. PagèS, “Enterobacter aerogenes and Enterobacter cloacae; versatile bacterial pathogens confronting antibiotic treatment,” Frontiers in Microbiology, vol. 6, May 2015, https:// doi. org/ 10. 3389/ fmicb. 2015. 00392
M. L. Mezzatesta, F. Gona, and S. Stefani, “Enterobacter cloacae Complex: Clinical Impact and Emerging Antibiotic Resistance,” Future Microbiology, vol. 7, no. 7, pp. 887–902, Jul. 2012, https:// doi. org/ 10. 2217/ fmb. 12. 61.
S. S. Fatima and E. A. Mussaed, “Biochemical and molecular characterization of common UTI pathogen,” in SpringerBriefs in applied sciences and technology, 2017, pp. 23–46. doi: 10.1007/978-981-10-4750-3_2.
J. H. Leitão, “Microbial virulence factors,” International Journal of Molecular Sciences, vol. 21, no. 15, p. 5320, Jul. 2020, doi: 10.3390/ijms21155320.
Y. Nami, B. Haghshenas, M. Haghshenas, and A. Y. Khosroushahi, “Antimicrobial activity and the presence of virulence factors and bacteriocin structural genes in Enterococcus faecium CM33 isolated from ewe colostrum,” Frontiers in Microbiology, vol. 6, Jul. 2015, doi: 10.3389/fmicb.2015.00782.
A. M. O’Hara, F. C. Tenover, and J. M. Miller, “Parallel comparison of accuracy of API 20E, Vitek GNI, MicroScan Walk/Away Rapid ID, and Becton Dickinson Cobas Micro ID-E/NF for identification of members of the family Enterobacteriaceae and common gram-negative, non-glucose-fermenting bacilli,” Journal of Clinical Microbiology, vol. 31, no. 12, pp. 3165–3169, Dec. 1993, doi: 10.1128/jcm.31.12.3165-3169.1993.
N. Di Tommaso, A. Gasbarrini, and F. R. Ponziani, “Intestinal barrier in human health and disease,” International Journal of Environmental Research and Public Health, vol. 18, no. 23, p. 12836, Dec. 2021, doi: 10.3390/ijerph182312836.
A A. H. Hammadi, "Isolation and identification of pathogenic bacteria from Al-Rystimya Station and their effects on public health," Journal Name, vol. 4, no. 12, pp. 1-8, Dec. 2015.
A. Bunyan and A. Q. J. Alkhuzaee, "Phenotypic detection of some virulence factors and antibiotics susceptibility of Enterobacter cloacae isolated from urinary tract infection," Journal Name, vol. 10, no. 7, pp. 669-677, Dec. 2017.
Bizzini and G. Greub, “Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, a revolution in clinical microbial identification,” Clinical Microbiology and Infection, vol. 16, no. 11, pp. 1614–1619, Jul. 2010, doi: 10.1111/j.1469-0691.2010.03311.x.
H. R. Al-Jabery et al., “Evaluation of some hematological parameters in HCV infected patients among blood donors at Thi-Qar province,” Academia Open, vol. 9, no. 2, Dec. 2024, doi: 10.21070/acopen.9.2024.10402.
M. Štefánek et al., “Antimicrobial Resistance and Biofilms Underlying Catheter-Related Bloodstream Coinfection by Enterobacter cloacae Complex and Candida parapsilosis,” Antibiotics, vol. 11, no. 9, p. 1245, Sep. 2022, doi: 10.3390/antibiotics11091245.
S. Fukuzawa et al., “High prevalence of colistin heteroresistance in specific species and lineages of Enterobacter cloacae complex derived from human clinical specimens,” Annals of Clinical Microbiology and Antimicrobials, vol. 22, no. 1, Jul. 2023, doi: 10.1186/s12941-023-00610-1.
F. Mosaffa, F. Saffari, M. Veisi, and O. Tadjrobehkar, “Some virulence genes are associated with antibiotic susceptibility in Enterobacter cloacae complex,” BMC Infectious Diseases, vol. 24, no. 1, Jul. 2024, doi: 10.1186/s12879-024-09608-2.
N. Kang et al., “Colistin heteroresistance in Enterobacter cloacae is regulated by PhoPQ‐dependent 4‐amino‐4‐deoxy‐l‐arabinose addition to lipid A,” Molecular Microbiology, vol. 111, no. 6, pp. 1604–1616, Mar. 2019, doi: 10.1111/mmi.14240.
Z. Zeng et al., “Carbapenem-Resistant Enterobacter cloacae Complex in Southwest China: Molecular Characteristics and Risk Factors Caused by NDM Producers,” Infection and Drug Resistance, vol. Volume 17, pp. 1643–1652, Apr. 2024, doi: 10.2147/idr.s447857.
H. Lahlaoui, A. B. H. Khalifa, and M. B. Moussa, “Epidemiology of Enterobacteriaceae producing CTX-M type extended spectrum β-lactamase (ESBL),” Médecine Et Maladies Infectieuses, vol. 44, no. 9, pp. 400–404, Sep. 2014, doi: 10.1016/j.medmal.2014.03.010.
A. Jayol, P. Nordmann, P. Lehours, L. Poirel, and V. Dubois, “Comparison of methods for detection of plasmid-mediated and chromosomally encoded colistin resistance in Enterobacteriaceae,” Clinical Microbiology and Infection, vol. 24, no. 2, pp. 175–179, Jun. 2017, doi: 10.1016/j.cmi.2017.06.002.
X. Gao et al., “Transcriptomic and phenotype analysis revealed the role of rpoS in stress resistance and virulence of pathogenic Enterobacter cloacae from Macrobrachium rosenbergii,” Frontiers in Microbiology, vol. 13, Nov. 2022, doi: 10.3389/fmicb.2022.1030955.
X. Gao et al., “Transcriptomic and phenotype analysis revealed the role of rpoS in stress resistance and virulence of pathogenic Enterobacter cloacae from Macrobrachium rosenbergii,” Frontiers in Microbiology, vol. 13, Nov. 2022, doi: 10.3389/fmicb.2022.1030955.
S. F. Bristy et al., “Misdiagnosis of bacterial pathogens by the diagnostic centers: a potential route for antibiotic resistance,” Journal of Applied Pharmaceutical Science, Jan. 2023, doi: 10.7324/japs.2024.175488.
X. Gao et al., “Transcriptomic and phenotype analysis revealed the role of rpoS in stress resistance and virulence of pathogenic Enterobacter cloacae from Macrobrachium rosenbergii,” Frontiers in Microbiology, vol. 13, Nov. 2022, doi: 10.3389/fmicb.2022.1030955.
A. Elbehiry et al., “Enterobacter cloacae from urinary tract infections: frequency, protein analysis, and antimicrobial resistance,” AMB Express, vol. 14, no. 1, Feb. 2024, doi: 10.1186/s13568-024-01675-7.
M. Ganbold, J. Seo, Y. M. Wi, K. T. Kwon, and K. S. Ko, “Species identification, antibiotic resistance, and virulence in Enterobacter cloacae complex clinical isolates from South Korea,” Frontiers in Microbiology, vol. 14, Mar. 2023, doi: 10.3389/fmicb.2023.1122691.
A. Selenic, D. R. Dodson, B. Jensen, M. J. Arduino, A. Panlilio, and L. K. Archibald, “Enterobacter cloacae bloodstream infections in pediatric patients traced to a hospital pharmacy,” American Journal of Health-System Pharmacy, vol. 60, no. 14, pp. 1440–1446, Jul. 2003, doi: 10.1093/ajhp/60.14.1440.
S. Cai et al., “High prevalence of carbapenem-resistant Enterobacter cloacae complex in a tertiary hospital over a decade,” Microbiology Spectrum, vol. 12, no. 12, Oct. 2024, doi: 10.1128/spectrum.00780-24.
F. Guérin et al., “Cluster-dependent colistin hetero-resistance inEnterobacter cloacaecomplex,” Journal of Antimicrobial Chemotherapy, vol. 71, no. 11, pp. 3058–3061, Jul. 2016, doi: 10.1093/jac/dkw260.
S. Liu et al., “Cluster Differences in Antibiotic Resistance, Biofilm Formation, Mobility, and Virulence of Clinical Enterobacter cloacae Complex,” Frontiers in Microbiology, vol. 13, Apr. 2022, doi: 10.3389/fmicb.2022.814831.
S. Y. Kim, H. J. Kim, S. H. Jeong, “Correlation between virulence genes and carbapenem resistance in Enterobacter cloacae complex” Microbial Drug Resistance, vol. 28, no. 4, pp. 560–566., Jul. 2022.
A. Morales, R. Cebrián, C. Ratia, “No significant association between virulence genes and antibiotic resistance in Enterobacter cloacae isolates” Journal of Medical Microbiology, vol. 69, no. 7, pp. 986–992., Jun. 2020.
T. K. W. Ling, Z. K. Liu, and A. F. B. Cheng, “Evaluation of the VITEK 2 System for Rapid Direct Identification and Susceptibility Testing of Gram-Negative Bacilli from Positive Blood Cultures,” Journal of Clinical Microbiology, vol. 41, no. 10, pp. 4705–4707, Oct. 2003, doi: 10.1128/jcm.41.10.4705-4707.2003.
A. J. Zakrzewski, U. Zarzecka, W. Chajęcka-Wierzchowska, and A. Zadernowska, “A Comparison of Methods for Identifying Enterobacterales Isolates from Fish and Prawns,” Pathogens, vol. 11, no. 4, p. 410, Mar. 2022, doi: 10.3390/pathogens11040410.
H. Wang, Y. Zhang, X. Liu, et al., "Emergence of carbapenem-resistant E. cloacae producing bla_NDM and bla_IMP in eastern China," BMC Infect. Dis., vol. 23, p. 156, 2023. [Online]. Available:
I. Vock, D. Müller, and R. Frei, "Antimicrobial susceptibility of Enterobacterales in Switzerland: amikacin retains efficacy," Swiss Med. Wkly., vol. 154, p. w30222, 2024. [Online]. Available:
J. Kim, D. Kim, H. Jung, et al., "Plasmid-mediated quinolone resistance in Enterobacter cloacae from ICUs," J. Glob. Antimicrob. Resist., vol. 28, pp. 94-100, 2022. [Online]. Available:
M. Tanaka, T. Okamoto, Y. Kato, et al., "Colistin susceptibility and mcr-9 detection in Enterobacter cloacae," J. Antimicrob. Chemother., vol. 78, no. 6, pp. 1458–1465, 2023. [Online]. Available:
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