Antibiotic Resistance Pattern of Acinetobacter baumannii Strains: A Retrospective Study from Oman

Epidemiology and antimicrobial resistance trends of Acinetobacter species in the United Arab Emirates: a retrospective analysis of 12 years of national AMR surveillance data

Introduction

Acinetobacter spp., in particular A. baumannii, are opportunistic pathogens linked to nosocomial pneumonia (particularly ventilator-associated pneumonia), central-line catheter-associated blood stream infections, meningitis, urinary tract infections, surgical-site infections, and other types of wound infections. A. baumannii is able to acquire or upregulate various resistance determinants, making it frequently multidrug-resistant, and contributing to increased mortality and morbidity. Data on the epidemiology, levels, and trends of antimicrobial resistance of Acinetobacter spp. in clinical settings is scarce in the Gulf Cooperation Council (GCC) and Middle East and North Africa (MENA) regions.

Methods

A retrospective 12-year analysis of 17,564 non-duplicate diagnostic Acinetobacter spp. isolates from the United Arab Emirates (UAE) was conducted. Data was generated at 317 surveillance sites by routine patient care during 2010-2021, collected by trained personnel and reported by participating surveillance sites to the UAE National AMR Surveillance program. Data analysis was conducted with WHONET.

Results

Species belonging to the A. calcoaceticus-baumannii complex were mostly reported (86.7%). They were most commonly isolated from urine (32.9%), sputum (29.0%), and soft tissue (25.1%). Resistance trends to antibiotics from different classes during the surveillance period showed a decreasing trend. Specifically, there was a significant decrease in resistance to imipenem, meropenem, and amikacin. Resistance was lowest among Acinetobacter species to both colistin and tigecycline. The percentages of multidrug-resistant (MDR) and possibly extensively drug-resistant (XDR) isolates was reduced by almost half between the beginning of the study in 2010 and its culmination in 2021. Carbapenem-resistant Acinetobacter spp. (CRAB) was associated with a higher mortality (RR: 5.7), a higher admission to ICU (RR 3.3), and an increased length of stay (LOS; 13 excess inpatient days per CRAB case), as compared to Carbapenem-susceptible Acinetobacter spp.

Conclusion

Carbapenem-resistant Acinetobacter spp. are associated with poorer clinical outcomes, and higher associated costs, as compared to carbapenem-susceptible Acinetobacter spp. A decreasing trend of MDR Acinetobacter spp., as well as resistance to all antibiotic classes under surveillance was observed during 2010 to 2021. Further studies are needed to explore the reasons and underlying factors leading to this remarkable decrease of resistance over time.

Antimicrobial Susceptibility Among Gram-Negative Isolates in Pediatric Patients in Latin America, Africa-Middle East, and Asia From 2016-2020 Compared to 2011-2015: Results From the ATLAS Surveillance Study

BACKGROUND

Antimicrobial resistance (AMR) data in the pediatric population are limited, particularly in developing countries. This study assessed the AMR profile and key resistance phenotypes and genotypes for Gram-negative bacteria (GNB) isolates collected as part of the Antimicrobial Testing Leadership and Surveillance program from pediatric patients in Latin America, Africa-Middle East, and Asia in 2016-2020 versus 2011-2015.

METHODS

Minimum inhibitory concentrations by broth microdilution methodology were interpreted per the Clinical and Laboratory Standards Institute. European Committee on Antimicrobial Susceptibility Testing breakpoints were used for interpreting colistin activity. β-lactamase genes were screened by polymerase chain reaction and sequencing.

RESULTS

For Acinetobacter baumannii, low susceptibility (<60.0%) was observed for all antimicrobials, except colistin (≥92.9%), across regions and year periods. Ceftazidime-avibactam, amikacin, colistin, and meropenem were mostly active (78.6%-100.0%) against Enterobacter cloacae, Escherichia coli, and Klebsiella pneumoniae. For Pseudomonas aeruginosa, susceptibility to ceftazidime-avibactam, amikacin, and colistin was ≥85.9%. Among resistance phenotypes, carbapenem-resistant (CR, ≥44.8%) and difficult-to-treat resistant (DTR, ≥37.1%) rates were the highest in A. baumannii. A consistent increase in CR and DTR K. pneumoniae was noted across regions over time. Extended-spectrum β-lactamases (ESBL)-producing K. pneumoniae (32.6%-55.6%) were more frequent than ESBL-producing E. coli (25.3%-37.1%). CTX-M was the dominant ESBL among Enterobacterales. NDM-positive Enterobacterales species and VIM-positive P. aeruginosa were identified across regions.

CONCLUSIONS

This study identified high susceptibility to few agents for key GNB in pediatric patients. Continued surveillance of resistance phenotypes and genotypes at regional levels may help to guide appropriate treatment decisions.

The optimized carbapenem inactivation method for objective and accurate detection of carbapenemase-producing Acinetobacter baumannii

The modified carbapenem inactivation method (mCIM) recommended by the Clinical and Laboratory Standards Institute is not applicable for detecting carbapenemases in Acinetobacter baumannii. Four currently reported phenotypic detection methods, namely, the modified Hodge test, the mCIM, the adjusted mCIM, and the simplified carbapenem inactivation method (sCIM), did not perform well in our 90 clinical A. baumannii isolates. Thus, the minimal inhibitory concentrations (MICs) of carbapenems and the existence and expression of carbapenemase-encoding genes were detected to explain the results. According to the E-test, which was more accurate than the VITEK 2 system, 80.0 and 41.1% were resistant to imipenem (IPM) and meropenem (MEM), respectively, and 14.4 and 53.3% exhibited intermediate resistance, respectively. Five β-lactamase genes were found, of which bla_OXA-51-like, bla_TEM, and bla_OXA-23-like were detected more frequently in 85 non-susceptible strains. The expression of bla_OXA-23-like was positively correlated with the MIC values of IPM and MEM. Therefore, an improved approach based on the mCIM, designated the optimized CIM (oCIM), was developed in this study to detect carbapenemases more accurately and reproducibly. The condition was improved by evaluating the factors of A. baumannii inoculum, incubation broth volume, and MEM disk incubation time. Obvious high sensitivity (92.94%) and specificity (100.00%) were obtained using the oCIM, which was cost-effective and reproducible in routine laboratory work.

Evaluation of the Effectiveness and Perceived Benefits of Interventional Structured Infection Prevention and Control Training Module Introduced in the Undergraduate Medical Curricula

INTRODUCTION

Assessing and improving infection prevention and control (IPC) knowledge and practicing skills among medical students who are the future medical practitioners is crucial for reducing the burden of healthcare-associated infections (HAIs). In this study, we assessed the IPC knowledge of undergraduate clinical-year medical students before and after interventional IPC modular training and evaluated the effectiveness and students' perception on structured modular IPC training presented to them.

METHODS

This cross-sectional interventional study was conducted on single medical cohort comprising of 145 final-year undergraduate medical students of the academic year 2022-23 at COMHS. Pre-test, post-test, and feedback questionnaire were used as the assessing tools. The data were collected, entered into Excel sheet, and analyzed using SPSS software version 22. McNemar and Paired-T tests were carried out, and a p value<0.05 was considered significant. Feedback of the questionnaire was analyzed using 3 Point Likert Scale as agree, neutral, and disagree.

RESULTS

Overall, mean IPC knowledge scores after training (37.65±1.37) was significantly higher as compared to before training (25.13±4.51). Prior knowledge scores on certain aspects of IPC such as duration of hand washing, steps of hand washing, sequence of donning and doffing of PPE, use of N95 mask, and appropriate sharp and needle precautions, and biomedical waste management were varied from 13.6% to 65.6%. However, overall participants' knowledge (p value <0.001) on these aspects increased significantly after the training. The majority of the participants (>90%) perceived IPC training as an excellent tool to improve IPC knowledge and practicing skills.

CONCLUSION

IPC training had a significant impact in gaining adequate IPC knowledge and practicing skills among our participants. Therefore, it is recommended that IPC training should be implemented in the undergraduate medical curriculum with greater emphasis on practicing skills.

Mobile genetic elements carrying aminoglycoside resistance genes in Acinetobacter baumannii isolates belonging to global clone 2

Aminoglycosides are used to treat infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) strains. However, resistance to aminoglycosides has increased remarkably in the last few years. Here, we aimed to determine the mobile genetic elements (MGEs) associated with resistance to aminoglycosides in the global clone 2 (GC2) A. baumannii. Among the 315 A. baumannii isolates, 97 isolates were identified as GC2, and 52 of GC2 isolates (53.6%) were resistant to all the aminoglycosides tested. The AbGRI3s carrying armA were detected in 88 GC2 isolates (90.7%), and of them, 17 isolates (19.3%) carried a new variant of AbGRI3 (AbGRI3_ABI221). aphA6 was located in TnaphA6 of 30 isolates out of 55 aphA6-harboring isolates, and 20 isolates were found to harbor TnaphA6 on a RepAci6 plasmid. Tn6020 carrying aphA1b was detected in 51 isolates (52.5%), which was located within AbGRI2 resistance islands. The pRAY^* carrying the aadB gene was detected in 43 isolates (44.3%), and no isolate was found to contain a class 1 integron harboring this gene. The GC2 A. baumannii isolates contained at least one MGE carrying the aminoglycoside resistance gene, located mostly either in the chromosome within AbGRIs or on the plasmids. Thus, it is likely that these MGEs play a role in the dissemination of aminoglycoside resistance genes in GC2 isolates from Iran.

Antimicrobial Resistance Among Pathogens Causing Bloodstream Infections: A Multicenter Surveillance Report Over 20 Years (1998–2017)

Purpose

Bloodstream infections (BSIs) are a common consequence of infectious diseases and cause high morbidity and mortality. Appropriate antibiotic use is critical for patients’ treatment and prognosis. Long-term monitoring and analysis of antimicrobial resistance are important in guiding physicians to choose appropriate antibiotics and understand the changes in antimicrobial resistance and infection control. Here, we report a retrospective study on the trends of antimicrobial resistance in the common BSI-associated pathogens.

Methods

The identification of strains and antimicrobial susceptibility tests were performed in each anticipating hospital independently. Data from the Hubei Province Antimicrobial Resistance Surveillance System (HBARSS) from 1998 to 2017 were retrospectively analyzed using WHONET 5.6 software.

Results

Data from HBARSS (1998–2017) revealed that 40,518 Gram-positive bacteria and 26,568 Gram-negative bacteria caused BSIs, the most common of which were Staphylococcus aureus and Escherichia coli. Salmonella typhi was a predominant BSI-associated pathogen in 1998–2003. Antimicrobial susceptibility data showed that the resistance rates of E. coli and Klebsiella pneumoniae to cefotaxime were significantly higher than those to ceftazidime. The proportion of strains of special antimicrobial resistance phenotypes including difficult-to-treat resistance (DTR), carbapenem-resistant (CR), extended-spectrum cephalosporin resistant (ECR) and fluoroquinolone resistant (FQR) in E. coli was 0.18%, 0.26%, 13.95%, 22.78% while in K. pneumoniae was 11.95%, 14.00%, 31.91% and 11.40%, respectively. In 2013–2017, K. pneumoniae showed resistance levels reaching 15.8% and 17.5% to imipenem and meropenem, respectively, and Acinetobacter baumannii showed high resistance rates ranging from 60 to 80% to common antibiotics. The detection rate of Salmonella typhi resistance to third-generation cephalosporins and fluoroquinolones was less than 5%. Control of methicillin-resistant Staphylococcus aureus (MRSA) remains a major challenge, and in 2009–2017, the MRSA detection rate was 40–50%.

Conclusion

Prevalence of CR K. pneumoniae has increased significantly in recent years. Resistance rates of A. baumannii to common antimicrobial agents have increased exponentially, reaching high levels. MRSA remains a challenge to control. For K. pneumoniae, DTR, CR, ECR and FQR were antimicrobial resistance phenotypes that could not be ignored while for E. coli DTR and CR were rare antimicrobial resistance phenotypes. CR K. pneumoniae, A. baumannii and MRSA present major challenges for controlling BSIs.

Antibiotics at the crossroads - Do we have any therapeutic alternatives to control the emergence and spread of antimicrobial resistance?

Antibiotics once regarded as magic bullets are no more considered so. Overuse of antibiotics in humans, agriculture, and animal husbandry has resulted in the emergence of a wide range of multidrug-resistant (MDR) pathogens which are difficult to treat. Antimicrobial resistance (AMR) is a serious global health problem associated with high mortality in the era of modern medicine. Moreover, in the absence of an effective antibiotic, medical and surgical interventions can highly become a risk. In recent times, the decreased incline of pharmaceutical industries toward research and development of newer effective antibiotics to fight this MDR pathogens have further fuelled the scarcity of antibiotics, thus the number of antibiotics in the pipeline is extremely limited. Hence it is high time for the development of new strategies to fight against dangerous MDR pathogens. Currently, several novel approaches explored by scientists have shown promising results pertaining to their antimicrobial activity against pathogens. In this article, the authors have summarized various novel therapeutic options explored to contain AMR with special attention to the mechanism of action, advantages, and disadvantages of different approaches.