Antimicrobial Susceptibility and Multidrug Resistance among Streptococcus pneumoniae Isolates from Predominantly Non-Sterile Respiratory Specimens in Children Hospitalized with Pneumonia or Suspected Bacteremia in the Mekong Delta, Vietnam, 2022–2024 :  A Hospital-Based Cross-Sectional Study

Nghia Quang Bui; Khai Quang Tran; Le Thi Nhu Tran; Long Duy Phun; Duy Khanh Nguyen; Duong Thai Bach; No Thi Tran; Tram Ngoc Ly; Thinh Nguyen; Hien Thi Nguyen

doi:10.33192/smj.v78i10.284093

Authors

Nghia Quang Bui Department of Pediatrics, Faculty of Medicine, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
Khai Quang Tran Department of Pediatrics, Faculty of Medicine, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
Le Thi Nhu Tran Department of Microbiology, Faculty of Medicine, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
Long Duy Phun Department of Pediatrics, Faculty of Medicine, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
Duy Khanh Nguyen Medical Student, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam.
Duong Thai Bach Medical Student, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
No Thi Tran Medical Student, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
Tram Ngoc Ly Medical Student, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam.
Thinh Nguyen Medical Student, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam
Hien Thi Nguyen Department of Nutrition and Food Safety, Faculty of Public Health, Can Tho University of Medicine and Pharmacy, Can Tho 94000, Vietnam

DOI:

https://doi.org/10.33192/smj.v78i10.284093

Keywords:

Streptococcus pneumoniae, Drug resistance, multiple, bacterial, Child, hospitalized, Pneumococcal vaccines, Vietnam

Abstract

Objective: To characterize antimicrobial susceptibility and multidrug resistance (MDR) among Streptococcus pneumoniae isolates from children hospitalized with pneumonia or suspected bacteremia in Vietnam’s Mekong Delta and explore factors associated with MDR.

Materials and Methods: This cross-sectional study included children aged 2 months–15 years with culture-confirmed S. pneumoniae and susceptibility results at a tertiary pediatric hospital during 2022–2024. Identification used conventional methods and VITEK 2 Compact; susceptibility testing used VITEK 2 AST-GP67 and Etest when indicated, and contemporaneous CLSI M100 criteria. MDR was defined as non-susceptibility to ≥1 agent in ≥3 classes with an independent pneumococcal CLSI criterion; screening tests and non-independent results (including surrogate ampicillin) were excluded. Associations were explored using Fisher’s exact test with Holm adjustment.

Results: Among 58 children, 38 (65.5%, 95% CI 52.7–76.4) had MDR isolates. Resistance was 100% to tetracycline, 65.5% to erythromycin, 63.3% to penicillin, and 52.2% to cefepime. Ceftriaxone was susceptible in 25/36 isolates (69.4%); all 58 isolates were vancomycin-susceptible. MDR occurred in 5/8 blood isolates and 33/50 nasopharyngeal aspirate isolates, reported descriptively. Absence of an underlying condition was associated with MDR after Holm adjustment (adjusted P=0.020); vaccination was not (adjusted P=0.367). Risk-factor analyses were exploratory and underpowered (20 non-MDR isolates).

Conclusion: MDR S. pneumoniae was common in this referral population. Because most isolates came from non-sterile respiratory specimens and testing was clinically directed, the 65.5% estimate should be interpreted as institution-level surveillance conditional on the observed testing panel rather than an unbiased population prevalence.

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