Methicillin Resistant Staphylococcus aureus and Extended Spectrum Beta-lactamase Producing Enterobacteriaceae: A Therapeutic Challenge in the 21st Century

Evaluating the effectiveness of the Ministry of Health restriction policy on seasonal antibiotic consumption trends in Saudi Arabia, 2016-2020

Background: Understanding antibiotic consumption patterns over time is essential to optimize prescribing practices and minimizing antimicrobial resistance. This study aimed to determine whether the antibiotics restriction policy launched by the Saudi Ministry of Health in April 2018 has impacted antibiotic use by assessing changes and seasonal variations following policy enforcement. Methods: Quarterly sales data of J01 antibacterial for systemic use in standard units were obtained from the IQVIA-MIDAS database, spanning from the first quarter of 2016 to the last quarter of 2020. Antibiotics consumption was measured in defined daily doses per 1,000 inhabitant per day- in a quarter (DDDdq). A comparative analysis of antibiotic consumption pre- and post-policy periods introduction was conducted by computing the average consumption values for each period. Statistical comparison of the mean differences between the two periods were then made using independent samples t-test, Mann-Whitney U Test where needed. Time series analysis was employed to estimate the projected antibiotic consumption in the post-policy period if the restriction policy had not been implemented, which was then compared to actual consumption values to evaluate the effectiveness of the restriction policy. Results: During the pre-policy, there were seasonal trends of the total and oral antibiotic consumption through quarters, with higher consumption observed in the first and fourth quarters. In contrast, parenteral antibiotic consumption did not appear to follow a clear seasonal pattern. Following the restriction policy, there was a significant reduction in total and oral antibiotic use, with mean reductions of -96.9 DDDdq (p-value = 0.002) and -98 DDDdq (p-value = 0.002), respectively. Conversely, a significant increase in parenteral antibiotic consumption was observed with a mean increase of +1.4 DDDdq (p-value < 0.0001). The comparison between the forecasted and actual models showed that the actual antibiotics consumption for total, oral, and parenteral were lower than the corresponding forecasted values by 30%, 31%, and 34%, respectively. Conclusion: Overall, our analysis of antibiotics consumption from 2016 to 2020 displays great success for the policy implemented by the Saudi Ministry of Health in significantly reducing the total and oral use of antibiotics. However, future studies are needed to explore the increased consumption of the parenteral antibiotics as well as the persistent high consumption patterns during the fall and winter months even after the implementation of the restriction policy.

Phenotypic and genotypic detection of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Accra, Ghana

AIM

To describe the occurrence of carbapenem resistance among multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae isolated from clinical specimens in Accra using phenotypic and genotypic methods.

METHODOLOGY

The study was cross-sectional, involving 144 clinical MDR E. coli and K. pneumoniae isolates recovered from the Central Laboratory of the Korle Bu Teaching Hospital (KBTH). The isolates were re-cultured bacteriologically, identified using standard biochemical tests, and subjected to antibiotic susceptibility testing using the Kirby-Bauer method. Carbapenem resistance was determined based on imipenem, meropenem, and ertapenem zones of inhibition, as well as minimum inhibitory concentrations (MICs). Carbapenemase production was determined phenotypically by modified Hodge test (MHT) and modified carbapenem inactivation method (mCIM), and genotypically with multiplex PCR targeting the blaKPC, blaIMP, blaNDM, blaVIM, and blaOXA-48 genes.

RESULTS

Of the 144 MDR isolates, 69.4% were E. coli, and 30.6% were K. pneumoniae. The distribution of antimicrobial resistance rates among them was ampicillin (97.2%), cefuroxime (93.1%), sulfamethoxazole-trimethoprim (86.8%), tetracycline (85.4%), cefotaxime and cefpodoxime (77.1% each), amoxicillin-clavulanate (75%), ceftriaxone (73.6%), ciprofloxacin (70.8%), levofloxacin (66.0%), cefepime (65.3%), ceftazidime (64.6%), gentamicin (48.6), piperacillin-tazobactam (40.3%), cefoxitin (14.6%), amikacin (13.9%), ertapenem and meropenem (5.6% each), and imipenem (2.8%). In total, 5.6% (8/144) of them were carbapenem-resistant (carbapenem MIC range = 0.094-32.0 μg/ml), with 75% (6/8) of these testing positive by the phenotypic tests and 62.5% (5/8) by the genotypic test (of which 80% [4/5] carried blaOXA-48 and 20% (1/5) blaNDM). The blaVIM, blaIMP, and blaKPC genes were not detected.

CONCLUSION

Although the rates of antibiotic resistance among the isolates were high, the prevalence of carbapenemase producers was low. The finding of blaOXA-48 and blaNDM warrants upscaling of antimicrobial resistance surveillance programmes and fortification of infection prevention and control programmes in the country.

Prevalence of Extended-Spectrum Beta Lactamase-Producing Microorganisms in Dr. Mohammad Hoesin Hospital Palembang

Production of Extended-Spectrum Beta-Lactamase (ESBL) by Enterobacteriaceae continues to be a problem of infectious diseases, especially in hospitals. The main causes of ESBL-producing bacteria colonization are urinary tract infections, length of hospital stay, invasive medical equipment, and antibiotics usage. This study aims to compare the incidence of ESBL based on the type of organism in Dr. Mohammad Hoesin Hospital for the 2017 and 2018 periods. The research design used was descriptive with a cross-sectional approach, which used secondary data at the Clinical Pathology Department of Dr. RSUP. Mohammad Hoesin Palembang. The findings of this study showed a decreasing pattern in the incidence of ESBL in 2017 and 2018, but with a similar pattern which was dominated by Klebsiella pneumoniae (followed by Escherichia coli and Klebsiella ozaenae), inpatients in pediatric wards, internal medicine, and intensive care units, and on sputum specimens. This study showed the presence of high levels of ESBL-producing bacteria (>60%) in Dr. Mohammad Hoesin Hospital, which was mainly caused by Klebsiella pneumoniae.

Impact of the WHO Integrated Stewardship Policy on the Control of Methicillin-Resistant Staphyloccus aureus and Third-Generation Cephalosporin-Resistant Escherichia coli: Using a Mathematical Modeling Approach

Methicillin-resistant Staphylococcus aureus (MRSA) and third-generation cephalosporin-resistant Escherichia coli (3GCREc) are community and hospital-associated pathogens causing serious infections among populations by infiltrating into hospitals and surrounding environment. These main multi-drug resistant or antimicrobial resistance (AMR) bacterial pathogens are threats to human health if not properly tackled and controlled. Tackling antimicrobial resistance (AMR) is one of the issues for the World Health Organization (WHO) to design a comprehensive set of interventions which also helps to achieve the end results of the developing indicators proposed by the same organization. A deterministic mathematical model is developed and studied to investigate the impact of the WHO policy on integrated antimicrobial stewardship activities to use effective protection measures to control the spread of AMR diseases such as MRSA and 3GCREc in hospital settings by incorporating the contribution of the healthcare workers in a hospital and the environment in the transmission dynamics of the diseases. The model also takes into account the parameters describing various intervention measures and is used to quantify their contribution in containing the diseases. The impact of combinations of various possible control measures on the overall dynamics of the disease under study is investigated. The model analysis suggests that the contribution of the interventions: screening and isolating the newly admitted patients, improving the hygiene in hospital settings, decolonizing the pathogen carriers, and increasing the frequency of disinfecting the hospital environment are effective tools to contain the disease from invading the population. The study revealed that without any intervention, the diseases will continue to be a major cause of morbidity and mortality in the affected communities. In addition, the study indicates that a coordinated implementation of the integrated control measures suggested by WHO is more effective in curtailing the spread of the diseases than piecemeal strategies. Numerical experiments are provided to support the theoretical analysis.

Synergism between WLBU2 peptide and antibiotics against methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing Enterobacter cloacae

Infections caused by Methicillin-Resistant Staphylococcus aureus (MRSA) and Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacter cloacae are considered as major therapeutic challenge due to their multidrug-resistant (MDR) phenotype against conventional antibiotics. WLBU2 is an engineered cationic peptide with potent antimicrobial activity. This in-vitro study aimed to evaluate the effects of WLBU2 against clinical isolates of the aforementioned bacteria and assess whether synergistic effects can be achieved upon combination with conventional antibiotics. The minimum inhibitory concentrations (MICs) of antimicrobial agents against bacterial clinical isolates (n = 30/strain) were determined using the microbroth dilution assay. The minimum bactericidal concentrations (MBCs) of WLBU2 were determined from microbroth dilution (MICs) tests by subculturing to agar plates. MICs of WLBU2 were evaluated in the presence of physiological concentrations of salts including NaCl, CaCl2 and MgCl2. To identify bacterial resistance profile, MRSA were treated with Oxacillin, Erythromycin and Vancomycin, while Ceftazidime, Ceftriaxone, Ciprofloxacin and Imipenem were used against Enterobacter cloacae. Combination treatments of antibiotics and sub-inhibitory concentrations of WLBU2 were conducted when MICs indicated intermediate/resistant susceptibility. The MICs/MBCs of WLBU2 were identical for each respective bacteria with values of 0.78-6.25 μM and 1.5-12.5 μM against MRSA and Enterobacter cloacae, respectively. WLBU2 was found as salt resistant. Combination treatment showed that synergistic and additive effects were achieved in many isolates of MRSA and Enterobacter cloacae. Our data revealed that WLBU2 is a potent peptide with bactericidal activity. In addition, it demonstrated the selective advantage of WLBU2 as a potential therapeutic agent under physiological solutions. Our findings also support the combination of WLBU2 and conventional antibiotics with potential application for treatment of resistant bacteria.

Environmental antimicrobial resistance and its drivers: a potential threat to public health

Imprudent and overuse of clinically relevant antibiotics in agriculture, veterinary and medical sectors contribute to the global epidemic increase in antimicrobial resistance (AMR). There is a growing concern among researchers and stakeholders that the environment acts as an AMR reservoir and plays a key role in the dissemination of antimicrobial resistance genes (ARGs). Various drivers are contributing factors to the spread of antibiotic-resistant bacteria and their ARGs either directly through antimicrobial drug use in health care, agriculture/livestock and the environment or antibiotic residues released from various domestic settings. Resistant micro-organisms and their resistance genes enter the soil, air, water and sediments through various routes or hotspots such as hospital wastewater, agricultural waste or wastewater treatment plants. Global mitigation strategies primarily involve the identification of high-risk environments that are responsible for the evolution and spread of resistance. Subsequently, AMR transmission is affected by the standards of infection control, sanitation, access to clean water, access to assured quality antimicrobials and diagnostics, travel and migration. This review provides a brief description of AMR as a global concern and the possible contribution of different environmental drivers to the transmission of antibiotic-resistant bacteria or ARGs through various mechanisms. We also aim to highlight the key knowledge gaps that hinder environmental regulators and mitigation strategies in delivering environmental protection against AMR.

Comparative Analysis of Consumer Exposure to Resistant Bacteria through Chicken Meat Consumption in Germany

Human exposure to bacteria carrying antimicrobial resistance (AMR) genes through the consumption of food of animal origin is a topic which has gained increasing attention in recent years. Bacterial transmission can be enhanced, particularly in situations in which the consumer pays less attention to hygiene practices, and consumer exposure to foodborne resistant bacteria through ready-to-eat foods could be increased. It has been demonstrated that even methicillin-resistant Staphylococcus aureus (MRSA) bacteria, which have low prevalence and concentration in raw chicken meat in Germany, may reach the consumer during barbecue events after failures in hygiene practices. This study aimed to quantify the consumer exposure to extended-spectrum beta-lactamase- (ESBL) or ampicillinase class C (AmpC) beta-lactamase-producing E. coli in Germany through the consumption of chicken meat and bread during household barbecues. The study considered cross-contamination and recontamination processes from raw chicken meat by using a previously-developed probabilistic consumer exposure model. In addition, a comparative analysis of consumer exposure was carried out between ESBL-/AmpC-producing E. coli and MRSA. Our results demonstrated that the probability of ESBL-/AmpC-producing E. coli reaching the consumer was 1.85 × 10^-5 with the number of bacteria in the final serving averaging 332. Given the higher prevalence and concentration of ESBL-/AmpC-producing E. coli in raw chicken meat at retail compared to MRSA, comparative exposure assessment showed that the likelihood and extent of exposure were significantly higher for ESBL-/AmpC-producing E. coli than for MRSA. ESBL-/AmpC-producing E. coli was determined to be 7.6 times likelier (p-value < 0.01) than MRSA to reach the consumer, with five times the concentration of bacteria in the final serving (p-value < 0.01).