A commentary published in Frontiers in Microbiology by Abdisalan Abdikarin Mohamed and colleagues evaluates a retrospective study investigating antimicrobial resistance patterns among ESKAPEE pathogens in intensive care units at a tertiary care hospital in Mogadishu, Somalia, from 2020 through 2024. While acknowledging that the original investigation by Ibrahim and colleagues contributes valuable local microbiological evidence to a critical clinical setting, the commentary emphasizes that interpreting these surveillance findings requires essential methodological clarifications. Specifically, the authors identify key concerns regarding laboratory validation protocols, conflicting multidrug resistance estimates, and the reporting of statistical uncertainty across annual resistance proportions.
The commentators explain that their critique addresses how the reported resistance data should be interpreted and utilized clinically, rather than disputing the pressing necessity of hospital-based surveillance in Somalia. Their foremost methodological concern centers on the antimicrobial susceptibility testing techniques described in the original study. While the retrospective investigation reported using Kirby-Bauer disk diffusion, including testing with vancomycin and colistin disks, the authors did not clearly describe organism-antibiotic-specific minimum inhibitory concentration confirmation for suspected resistant isolates.
To contextualize these testing requirements, Mohamed and colleagues reference standard guidance from public health and standards organizations. Guidance from the Centers for Disease Control and Prevention explicitly advises against disk diffusion for testing vancomycin susceptibility in Staphylococcus aureus. Instead, CDC protocols recommend that any suspected intermediate or resistant S. aureus results be confirmed through repeat organism identification alongside a validated minimum inhibitory concentration method, ensuring screening results are not prematurely characterized as resistant phenotypes.
A parallel testing limitation affects the surveillance data for colistin. Joint recommendations from the Clinical and Laboratory Standards Institute and the European Committee on Antimicrobial Susceptibility Testing designate broth microdilution as the international reference method for colistin susceptibility testing and do not recommend disk diffusion. In the Somali retrospective dataset, Ibrahim and colleagues reported low colistin resistance in Klebsiella pneumoniae and an approximate 6% vancomycin resistance rate in S. aureus in 2024, despite explicitly acknowledging that vancomycin-resistant S. aureus had not been systematically assessed.
Because screening assays alone cannot establish verified resistance, the commentary calls on the original researchers to state the exact laboratory methods, minimum inhibitory concentration values, and interpretive criteria applied to these isolates. Organism-antibiotic-specific interpretive criteria are established in CLSI M100 and EUCAST breakpoint tables. Mohamed and colleagues urge the study authors to clarify which specific standards and versions were utilized in each observation year and whether historical susceptibility data were reinterpreted using a consistent, common standard version rather than presenting initial screening results as confirmed vancomycin-intermediate or vancomycin-resistant S. aureus.
The commentary raises a second major methodological concern regarding conflicting multidrug resistance estimates presented within the retrospective study. The authors point out a substantial discrepancy between summary statements and detailed tabular findings: the study abstract reports multidrug resistance in 85% of Acinetobacter baumannii isolates and 78% of K. pneumoniae isolates, whereas Table 4 records multidrug resistance in 150 of 194 isolates, or 77.3%, for A. baumannii and 70 of 144 isolates, or 48.6%, for K. pneumoniae.
This inconsistency leaves readers uncertain whether distinct analytical subpopulations, varied criteria, or differing denominators account for the divergent percentages. Citing the internationally accepted consensus definition by Magiorakos and colleagues, which defines multidrug resistance as acquired non-susceptibility to at least one agent in three or more antimicrobial categories, the commentators ask the authors to explain how their operational definition was applied in practice. They note that clarification is needed on how intermediate susceptibility results, incomplete testing panels, and missing multidrug resistance classifications were handled across the analyzed isolate cohorts.
A third critical issue highlighted in the commentary involves the presentation of annual resistance percentages without transparent testing denominators or statistical uncertainty metrics. Although Ibrahim and colleagues acknowledged encountering sparse sample sizes and missing organism-year observations in their hospital dataset, several reported annual metrics remain problematic. For instance, Table 3 reports 100% resistance in Enterobacter against multiple antimicrobial agents in 2023, yet each of these figures was derived from a single resistant isolate, demonstrating that only one isolate was tested that year.
The commentators point out that an estimate derived from a single bacterial isolate provides negligible statistical evidence of a true temporal shift in pathogen resistance across the patient population. To make underlying statistical uncertainty fully visible to clinicians and epidemiologists, Mohamed and colleagues advise reporting exact resistant-to-tested isolate counts alongside corresponding 95% confidence intervals for every organism-antibiotic-year pairing. They also request clarification on isolate deduplication protocols, specifically whether analyses were restricted to the first isolate per patient and organism or encompassed repeat clinical episodes.
In accordance with CLSI M39 guidelines, distinguishing routine cumulative antibiograms from focused surveillance intended to detect emerging resistance is essential for aligning analytical methods with clinical goals. Furthermore, the commentary notes that the study’s endpoint in October 2024 restricts direct comparisons of full-year isolate counts, although an incomplete year does not intrinsically bias resistance proportions. The commentary concludes that documenting robust susceptibility confirmation, reconciled multidrug resistance denominators, and explicit uncertainty boundaries will strengthen confidence in local surveillance and help clinicians differentiate preliminary signals from actionable data for empirical intensive care treatment protocols.
The commentary, titled “Interpreting ESKAPEE Resistance Trends in Somali Intensive Care Units: Laboratory Validation, Data Consistency, and Statistical Uncertainty,” reflects an academic collaboration among researchers based at Somali National University, the Somali National University Faculty of Health Science and Tropical Medicine, the Benadir Research Consultancy and Evaluation Center, and Salaam University in Mogadishu. While recognizing the value of local hospital data generated by Ibrahim and colleagues, the authors emphasize that rigorous methodological transparency must underpin regional surveillance to make evidence clinically actionable.
A primary concern raised by the authors involves preventing preliminary laboratory screening results from being mischaracterized as confirmed resistance phenotypes. Mohamed and colleagues specifically warn against reporting unverified observations as confirmed vancomycin-intermediate Staphylococcus aureus or vancomycin-resistant Staphylococcus aureus, designated as VISA and VRSA. Because Ibrahim and colleagues acknowledged that vancomycin-resistant S. aureus had not been systematically assessed, their report of approximately 6% vancomycin resistance in 2024 requires validated confirmation rather than reliance on Kirby-Bauer disk diffusion. In line with Centers for Disease Control and Prevention guidance, any suspected intermediate or resistant S. aureus isolate demands repeat organism identification and validated minimum inhibitory concentration testing before being presented as a confirmed resistant pathogen.
The commentary further examines the interpretive standards governing antimicrobial susceptibility testing across longitudinal hospital studies. Both the Clinical and Laboratory Standards Institute M100 guidelines and the European Committee on Antimicrobial Susceptibility Testing breakpoint tables provide organism-antibiotic-specific interpretive criteria that are revised periodically.
Similar methodological scrutiny applies to Gram-negative pathogens, particularly colistin susceptibility testing in Klebsiella pneumoniae isolates. Joint CLSI and EUCAST guidance identifies broth microdilution as the international reference standard and explicitly advises against using disk diffusion methods for colistin. Mohamed and colleagues observe that while the retrospective dataset reported low colistin resistance in K. pneumoniae, the lack of clearly described broth microdilution methods, reported minimum inhibitory concentration values, and defined interpretive criteria leaves clinicians unable to verify whether these findings represent true, validated microbiological phenotypes.
The commentary also addresses the need for methodological precision when operationalizing definitions of multidrug resistance. The substantial discrepancies between the study abstract and Table 4, where Acinetobacter baumannii multidrug resistance shifts from 85% to 77.3% across 150 of 194 isolates, and K. pneumoniae drops from 78% to 48.6% across 70 of 144 isolates, indicate potential differences in analytical subpopulations or denominators. The authors note that applying the internationally recognized consensus definition established by Magiorakos and colleagues, which requires acquired non-susceptibility to at least one agent in three or more antimicrobial categories, necessitates transparent reporting. The researchers must clarify how intermediate susceptibility results were categorized, how incomplete testing panels were managed, and how many isolates were included in each analysis.
Statistical uncertainty and sample size transparency represent another fundamental theme in the commentary. In critical care surveillance, sparse sample sizes and missing organism-year observations can generate misleading conclusions if reported without appropriate context. For example, Table 3 recorded 100% resistance in Enterobacter across multiple agents in 2023, yet this figure represented a single resistant isolate out of only one isolate tested. Mohamed and colleagues argue that a single isolate provides negligible evidence of an institutional or temporal resistance shift. To make statistical uncertainty visible, surveillance analyses must present exact resistant-to-tested isolate counts alongside corresponding 95% confidence intervals for each organism-antibiotic-year combination, enabling clinicians to distinguish isolated occurrences from statistically supported clinical trends.
Subject of Research: Methodological evaluation and surveillance reporting standards for intensive care unit pathogen resistance in Somalia
Article Title: Commentary: Antimicrobial resistance trends of ESKAPEE pathogens isolated from intensive care unit patients at a tertiary care hospital in Mogadishu, Somalia: a retrospective study (2020–2024)
Article References: Mohamed, A. A., Mohamed, A. O., Abdi, A. M., & Samaan, A. H. (2026). Commentary: Antimicrobial resistance trends of ESKAPEE pathogens isolated from intensive care unit patients at a tertiary care hospital in Mogadishu, Somalia: a retrospective study (2020–2024). Frontiers in Microbiology, 17, Article 2021086. https://doi.org/10.3389/fmicb.2026.2021086
Image Credits: AI Generated
DOI: 10.3389/fmicb.2026.2021086
Keywords: ESKAPEE pathogens, antimicrobial resistance, intensive care units, Mogadishu, Somalia, Kirby-Bauer disk diffusion, broth microdilution, minimum inhibitory concentration, vancomycin resistance, colistin resistance, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Enterobacter, multidrug resistance, CLSI M100, EUCAST breakpoints, CLSI M39
News Source: Kristina Jarvis. (November 12, 2026). Commentary Urges Methodological Validation for Somali Intensive Care Pathogen Resistance Data. Scienmag.
