Antibiotic resistance patterns of carbapenemase-producing Enterobacterales in Mohammed VI University Hospital of Marrakech, Morocco

Epidemiology and clinical characteristics of patients with carbapenem-resistant enterobacterales infections: experience from a large tertiary care center in a developing country

BACKGROUND

Carbapenem-resistant Enterobacterales (CREs) are a significant source of healthcare-associated infections. These bacteria are difficult to treat and have a high mortality rate due to high rates of antibiotic resistance. These pathogens are also linked to major outbreaks in healthcare institutions especially those with limited resources in infection prevention and control (IPC). Therefore, our study aimed to describe the epidemiology and clinical characteristics of patients with carbapenem-resistant Enterobacteriaceae in a referral hospital in a developing country.

METHODS

This was a retrospective cross-sectional study that included 218 patients admitted to An-Najah National University Hospital between January 1, 2021, and May 31, 2022. The target population was all patients with CRE infection or colonization in the hospital setting.

RESULTS

Of the 218 patients, 135 had CR-Klebsiella pneumoniae (61.9%), and 83 had CR-Escherichia coli (38.1%). Of these, 135 were male (61.9%) and 83 were female (38.1%), with a median age of 51 years (interquartile range 24-64). Malignancy was a common comorbidity in 36.7% of the patients. Approximately 18.3% of CRE patients were obtained from patients upon admission to the emergency department, the largest percentage among departments. Most CRE pathogens were isolated from rectal swabs, accounting for 61.3%. Among the 218 patients, colistin was the most widely used antimicrobial agent (13.3%). CR- E. coli showed resistance to amikacin in 23.8% of the pathogens tested and 85.7% for trimethoprim/sulfamethoxazole compared to CR- K. pneumonia, for which the resistance to trimethoprim/sulfamethoxazole was 74.1%, while for amikacin it was 64.2%. Regarding meropenem minimum inhibitory concentration, 85.7% of CR- E. coli were greater than 16 µg/mL compared to 84% of CR- K. pneumonia isolates.

CONCLUSION

This study found that CRE is frequently reported in this tertiary care setting, implying the presence of selective pressure and transmission associated with healthcare setting. The antibiotics tested showed a variety of resistance rates, with CR-K. pneumoniae being more prevalent than CR-E. coli, and exhibiting an extremely high resistance pattern to the available therapeutic options.

Detection of Carbapenemase Encoding Gene and Resistance to Cefiderocol in Hospital and Community eXtensive Drug Resistance and Carbapenem-Resistant Pseudomonas aeruginosa Strains in Morocco

Pseudomonas aeruginosa (Pa) remains among clinically-significant Gram-negative species. The carbapenems are often the last resort for treating infections due to multidrug resistant isolates such as Pa. The carbapenems' efficacy is increasingly compromised by the emergence and the rapid spread of Pa carrying carbapenemases which represent a serious threat to public health. This study aimed to establish the resistance profile and to identify carbapenemase genes in isolates with imipenem resistant phenotypes. Among 134 Pa isolates collected both in the community (46) and hospital (88) from January 2021 to December 2021 in Morocco, 18 (8 were from the community and 10 from the hospital settings) were carbapenem resistant. The identification of these strains has been confirmed using matrix assisted laser desorption ionization-time of flight (MALDI-TOF). The antibiotic susceptibility testing against 16 antibiotics was carried out and interpreted according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing (2021). The worrying antibiotics resistance profiles, which spread to cefiderocol for two isolates, were obtained for all isolates, which were eXtensive Drug Resistance showing highly resistant to all antibiotic categories tested, even to ceftolozane-tazobactam. Colistin (100% susceptible) and cefiderocol (88.88%) were the most active agents against carbapenem-resistant Pa (CRPa). Phenotypic detection by NP-CARBA and NG-CARBA tests of metallo‑β‑lactamase (MβL) production was confirmed by PCR amplification and sequencing. Three CRPa isolates coharboring blaVIM-2-blaNDM-1 (two isolates) and blaVIM-2-blaIMP-8 (one isolate) genes were detected. In this study, we describe the coexistence of these MβL genes and the cefiderocol resistance in CRPa strains in Morocco. The alarming antibiotic resistance patterns of all these CRPa isolates and their resistance genes emphasize the importance of antimicrobial susceptibility testing in the choice of antibiotics for treating Pa infections.

Prevalence, antibiotic resistance profile, MBLs encoding genes, and biofilm formation among clinical carbapenem-resistant Enterobacterales isolated from patients in Mohammed VI University Hospital Centre, Morocco

Enterobacterales are frequently a major cause of human infections. The emergence of carbapenem resistance as well as the biofilm formation complicate their management. In this regard, this study aimed to investigate the prevalence, antibiogram, carbapenemase genes, and biofilm production among Enterobacterales. For this purpose, 18 172 clinical specimens from hospitalized patients at Mohammed VI University Hospital were collected over two years (2018-2019). The bacteriological investigation was performed to isolate Enterobacterales. Subsequently, BD-Phoenix and MALDI-TOF-MS were used for bacterial identification. The production of ESBLs and carbapenemases was assessed using phenotypic tests and PCR. The biofilm formation was eventually carried out. Out of 195 carbapenem-resistant Enterobacterales strains, 190 were carbapenemase producers, and 74 Enterobacterales produced metallo-beta-lactamases (MBLs). The PCR results revealed that blaNDM was the most common carbapenemase gene, present in 62 cases, followed by the co-existence of blaNDM and blaOXA-48 in 12 cases. Klebsiella pneumoniae was the most frequently identified species among the 74 New Delhi metallo-β-lactamase (NDM) isolates and the XDR resistance phenotype was the most prevalent with 58.10%. Additionally, all 74 NDM-positive Enterobacterales were able to form biofilms, with 82.4% being strong producers. This study highlights the need for rapid detection of carbapenemase and biofilm production in our hospital to manage this health concern.

Predominance of OXA-48 Carbapenemase-Producing Enterobacterales in a Moroccan Hospital

Objective

The emergence of carbapenemase-producing Enterobacterales (CPE) is a major concern that is increasingly reported worldwide. Our study aimed at investigating the resistance of CPE isolates in a Moroccan teaching hospital using phenotypic and genotypic methods.

Methods

Enterobacterales strains from March to June 2018 were collected from different clinical samples. The Enterobacterales isolates resistant to third-generation cephalosporins (3GC) and/or carbapenems were subjected to the Carba NP test and an immunochromatographic test for phenotypic detection. Detection of extended-spectrum β-lactamases (ESBL) was also performed following standards. Molecular screening of carbapenemases genes (OXA-48, NDM, blaKPC, blaIMP, blaVIM, and blaOXA-24, blaOXA-23, OXA-51, OXA-58) using conventional multiplex PCR assays was also performed on 143 isolates.

Results

Enterobacterales represented 52.7% with a proportion of 21.8% of bacteria resistant to 3GC and/or carbapenems. Within 143 isolates MDR to 3GC, K. pneumoniae, E. coli, and E. cloacae represent 53.1%, 40.6%, and 6.3%, respectively. These strains were isolated mainly from urinary samples (74.8%) in patients admitted to emergency and surgical units. 81.1% of strains are producing ESBL and 29% are carbapenemase producers as confirmed by the Carba NP test, immunochromatographic test, and molecular testing. OXA-48 carriers represent 83.3% of these strains, followed by NDM with 16.7%. blaKPC, blaIMP, blaVIM, and blaOXA-24, blaOXA-23, OXA-51, OXA-58 were not detected in any of these bacteria.

Conclusions

A high rate of CPE carrying OXA-48 among Enterobacterales resistant to 3GC and/or carbapenems isolates was found. Strict observance of hospital hygiene measures and more rational use of antibiotics are mandatory. Implantation of carbapenemases detection should be encouraged in our hospital settings to estimate the true burden of the CPE.

Multidrug-Resistant Bacteria Isolated from Blood Culture Samples in a Moroccan Tertiary Hospital: True Bacteremia or Contamination?

Purpose

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.