Integrating Antimicrobial Susceptibility Profiles and Laboratory Biomarker Abnormalities in Hospitalized Inpatients: A Single-Center Retrospective Study from Jazan, Saudi Arabia

Background: Antimicrobial resistance (AMR) is a major challenge among hospitalized patients, particularly when bacterial infection coexists with laboratory evidence of organ dysfunction. This study assessed AMR patterns and laboratory abnormality burden among hospitalized patients in Jazan, Saudi Arabia. Methods: This retrospective single-center study included 43 hospitalized patients with a culture-positive bacterial isolate and antimicrobial susceptibility testing (AST) results at King Fahd Central Hospital, Jazan, Saudi Arabia, from 1 January 2019 to 1 January 2022. Demographic, ward, organism-identification, antimicrobial susceptibility, hematological, coagulation, and biochemical data were analyzed. Only AST results for agents applicable to the identified organism were analyzed. Multidrug resistance (MDR) was primarily defined as non-susceptibility to at least one antimicrobial agent in three or more antimicrobial categories, with intermediate and resistant results grouped as non-susceptible. An alternative resistance-based sensitivity analysis classified isolates as MDR when resistance was detected to three or more individual antimicrobial agents, regardless of antimicrobial category. Laboratory abnormalities were classified using institutional reference ranges, with sex-specific hemoglobin intervals and a random-glucose threshold of >140 mg/dL. Results: The median age was 41 years (IQR, 28.0–58.5), and 22 patients were female (51.2%). The most frequent admission locations were the intensive care unit (27.9%), female medical ward (20.9%), and male neurology ward (20.9%). Gram-negative bacilli accounted for 60.5% of the total isolates. The most common organisms were Staphylococcus epidermidis (20.9%), Klebsiella pneumoniae (20.9%), and Acinetobacter baumannii complex (16.3%). MDR was identified in 30/43 isolates (69.8%) using the primary class-based non-susceptibility definition and in 30/43 isolates (69.8%) using the alternative resistance-based definition. All MDR-stratified clinical and laboratory comparisons were based on the primary class-based definition. High resistance rates were observed for oxacillin (11/11 staphylococci, 100%), erythromycin (81.2%), levofloxacin (61.1%), imipenem (56.0%), ceftazidime (53.8%), meropenem (50.0%), and cefepime (50.0%) among the tested isolates. No resistance was detected to vancomycin, teicoplanin, or tigecycline. Laboratory abnormalities were frequent, including anemia (73.8%), leukocytosis (33.3%), platelet abnormalities (47.6%), hyperglycemia (27.9%), elevated blood urea nitrogen (BUN) (67.4%), elevated creatinine (32.6%), hypoalbuminemia (71.4%), and elevated INR (52.9%). In exploratory MDR-stratified comparisons (30 MDR vs. 13 non-MDR), platelet counts were lower in the MDR group (p = 0.032), but no laboratory difference remained significant after correction for multiple comparisons, and these comparisons were underpowered, so the absence of significant differences does not exclude an association. Conclusions: Hospitalized patients in this cohort showed a high burden of AMR and frequent hematological, renal, metabolic, hepatic, and coagulation abnormalities. These descriptive findings highlight the need for denominator-aware, organism-specific AMR surveillance; whether integrating routine laboratory biomarkers into antimicrobial stewardship improves outcomes was not evaluated and requires a prospective study. Larger multicenter studies are needed to determine whether the MDR phenotype independently predicts adverse clinical outcomes.