Infection and Drug Resistance (Sep 2022)
Multidrug-Resistant Bacteria Isolated from Blood Culture Samples in a Moroccan Tertiary Hospital: True Bacteremia or Contamination?
Abstract
Soumia Nachate,1 Salma Rouhi,1 Hicham Ouassif,1 Hind Bennani,1 Abdelhamid Hachimi,2 Youssef Mouaffak,3 Said Younous,3 Fatiha Bennaoui,4 Nadia El Idrissi Slitine,4 Fadl Mrabih Rabou Maoulainine,4 Asmae Lamrani Hanchi,1 Nabila Soraa1 1Department of Microbiology, Mohamed VI University Hospital Center, Marrakech, Morocco; 2Department of Intensive Care, Mohamed VI University Hospital Center, Marrakech, Morocco; 3Pediatric Intensive Care Department, Mohamed VI University Hospital Center, Marrakech, Morocco; 4Neonatal Intensive Care Department, Mohamed VI University Hospital Center, Marrakech, MoroccoCorrespondence: Soumia Nachate, Department of Microbiology, Mohamed VI University Hospital Center, BP2360 Principal, Ibn Sina Avenue, Marrakech, 40160, Morocco, Tel +212 658956312, Email [email protected]: To demonstrate the relevance of clinico-biological correlation in the interpretation of positive blood cultures (BC) for multidrug-resistant (MDR) bacteria, among adult and pediatric patients, in order to distinguish between true bacteremia (TB) and contaminations and to evaluate the impact on patient management.Patients and Methods: This six-month study was conducted at Mohammed VI University Hospital in Marrakech. All MDR bacteria isolated from BCs carried out on hospitalized patients during this period were included. For each positive BC to MDR microorganism, demographic and clinical characteristics, laboratory findings, therapeutic and evolution data were collected.Results: TB was considered in 157 (94.6%) of the 166 positive-culture episodes for MDR bacteria, while 9 (5.4%) were classified as false-positive. Contamination rate was 0.2% (9/3824). TB and contaminations occurred mainly in intensive care units (ICUs), with the neonatal ICU being the most concerned (p = 0.016). Clinical signs of sepsis were present in all TB patients, with a significant difference between the two groups (p = 0.000). CRP values were higher in the TB group (p = 0.000). The most isolated true pathogens were ESBL-producing Enterobacterales (50%) and carbapenem-resistant Enterobacterales (33.3%). They also predominated in contaminated BCs. Isolation of the same microorganism from other sites was significantly associated with TB (p = 0.012). In contrast to the contaminations group, the difference in the clinical course of TB patients, according to whether or not they received appropriate probabilistic antibiotics, was statistically significant (p = 0.000). These patients had longer hospital stays and longer durations of antibiotic therapy. The overall mortality rate was 39.6%.Conclusion: Distinguishing between MDR-positive BCs representing clinically significant bacteremia or simple contamination requires a careful clinical, biological, and microbiological confrontation of each MDR positive BC in order to avoid unnecessary overuse of broad-spectrum antibiotics and thus reduce resistance selective pressure.Keywords: blood culture, multidrug-resistant bacteria, clinico-biological correlation, true bacteremia, contamination
