Antimicrobial susceptibility patterns of respiratory Gram-negative bacterial isolates from COVID-19 patients in Switzerland

Impact of coronavirus disease 2019 (COVID-19) on antimicrobial resistance among major pathogens causing healthcare-associated infection

BACKGROUND

Coronavirus disease 2019 (COVID-19) has caused great impact on healthcare systems, including antibiotic usage and multi-drug resistant (MDR) bacterial infections at hospitals. We aim to investigate the trends of antimicrobial resistance among the major pathogens causing healthcare-associated infection (HAI) at intensive care units (ICU).

MATERIAL AND METHODS

The demographic characteristics of hospitalization, usage of antimicrobial agents, counted by half-an-year DID (defined daily dose per 1000 patient-days), and HAI density of five major MDR bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Klebsiella pneumoniae (CRKP), and carbapenem-resistant Pseudomonas aeruginosa (CRPA), of ICU patients at a medical center in Taiwan during January 2017 to December 2021 were collected and analyzed.

RESULTS

The total antibiotic usage, counted by DID, had a significant increasing trend, before COVID-19 occurrence in 2017-2019, but no further increase during the pandemic period in 2020-2021. However, comparing the two time periods, antibiotics consumption was significantly increased during pandemic period. There was no significant change of HAI density in MRSA, VRE, CRAB, CRKP, and CRPA, comparing the pandemic to the pre-pandemic period. Although, CRKP and CRPA infection rates were increasing during the pre-pandemic period, there was no further increase of CRKP and CRPA HAI rates during the pandemic period.

CONCLUSION

During COVID-19 pandemic, there was no significant increase in HAI density of five major MDR bacteria at ICU in Taiwan, despite increased antibiotic usage. Strict infection prevention measures for COVID-19 precautions and sustained antimicrobial stewardship probably bring these effects.

Resistance Transition of Pseudomonas aeruginosa in SARS-CoV-2-Uninfected Hospitalized Patients in the Pandemic

Objective

To investigate the impact of coronavirus disease 2019 (COVID-19) specified preventive and control measures on the distribution and resistance transition of Pseudomonas aeruginosa (P. aeruginosa) in uninfected hospitalized patients during the pandemic.

Methods

This retrospective study retrieved data from 316 P. aeruginosa isolates in the year pre-COVID-19 (n=131) pandemic and the year under COVID-19 specified preventive and control (post-pandemic year, n=185), compared the general characteristics, laboratory results, and antimicrobial susceptibility tests of P. aeruginosa between the two groups.

Results

Compared with the pre-pandemic year, the isolation rate of P. aeruginosa (14.35% vs 22.31%, P<0.001) increased, while the rate of drug resistant P. aeruginosa decreased significantly (29.77% vs 19.45%, P<0.001) in the post-pandemic year; Prescription of β-Lactams (30.5% vs 50.0%, P<0.01) also increased significantly. The resistance rates of P. aeruginosa isolates to ceftazidime (P<0.01), ciprofloxacin (P<0.01), and gentamicin (P<0.001) increased, whereas the resistance rates to piperacillin/tazobactam (P<0.01) and imipenem (P<0.05) decreased significantly.

Conclusion

The COVID-19 specified preventive and control measures have influenced the distribution and resistance transition of P. aeruginosa, further verifications are needed in future research.

An intensive care unit outbreak with multi-drug-resistant Pseudomonas aeruginosa - spotlight on sinks

BACKGROUND

Pseudomonas aeruginosa and other Gram-negative bacteria have the ability to persist in moist environments in healthcare settings, but their spread from these areas can result in outbreaks of healthcare-associated infections.

METHODS

This study reports the investigation and containment of a multi-drug-resistant P. aeruginosa outbreak in three intensive care units of a Swiss university hospital. In total, 255 patients and 276 environmental samples were screened for the multi-drug-resistant P. aeruginosa outbreak strain. The environmental sampling and molecular characterization of patient and environmental strains, and control strategies implemented, including waterless patient care, are described.

RESULTS

Between March and November 2019, the outbreak affected 29 patients. Environmental sampling detected the outbreak strain in nine samples of sink siphons of three different intensive care units with a common water sewage system, and on one gastroscope. Three weeks after replacement of the sink siphons, the outbreak strain re-grew in siphon-derived samples and newly affected patients were identified. The outbreak ceased after removal of all sinks in the proximity of patients and in medication preparation areas, and minimization of tap water use. Multi-locus sequence typing indicated clonality (sequence type 316) in 28/29 patient isolates and all 10 environmental samples.

CONCLUSIONS

Sink removal combined with the introduction of waterless patient care terminated the multi-drug-resistant P. aeruginosa outbreak. Sinks in intensive care units may pose a risk for point source outbreaks with P. aeruginosa and other bacteria persisting in moist environments.

Antibiotic-Resistant ESKAPE Pathogens and COVID-19: The Pandemic beyond the Pandemic

Antibacterial resistance is a renewed public health plague in modern times, and the COVID-19 pandemic has rekindled this problem. Changes in antibiotic prescribing behavior, misinformation, financial hardship, environmental impact, and governance gaps have generally enhanced the misuse and improper access to antibiotics during the COVID-19 pandemic. These determinants, intersected with antibacterial resistance in the current pandemic, may amplify the potential for a future antibacterial resistance pandemic. The occurrence of infections with multidrug-resistant (MDR), extensively drug-resistant (XDR), difficult-to-treat drug-resistant (DTR), carbapenem-resistant (CR), and pan-drug-resistant (PDR) bacteria is still increasing. The aim of this review is to highlight the state of the art of antibacterial resistance worldwide, focusing on the most important pathogens, namely Enterobacterales, Acinetobacter baumannii, and Klebsiella pneumoniae, and their resistance to the most common antibiotics.

Early Bacterial Coinfections in Patients Admitted to the ICU With COVID-19 or Influenza: A Retrospective Cohort Study

Previous findings suggest that bacterial coinfections are less common in ICU patients with COVID-19 than with influenza, but evidence is limited.

OBJECTIVES

This study aimed to compare the rate of early bacterial coinfections in ICU patients with COVID-19 or influenza.

DESIGN SETTING AND PARTICIPANTS

Retrospective propensity score matched cohort study. We included patients admitted to ICUs of a single academic center with COVID-19 or influenza (January 2015 to April 2022).

MAIN OUTCOMES AND MEASURES

The primary outcome was early bacterial coinfection (i.e., positive blood or respiratory culture within 2 d of ICU admission) in the propensity score matched cohort. Key secondary outcomes included frequency of early microbiological testing, antibiotic use, and 30-day all-cause mortality.

RESULTS

Out of 289 patients with COVID-19 and 39 patients with influenza, 117 (n = 78 vs 39) were included in the matched analysis. In the matched cohort, the rate of early bacterial coinfections was similar between COVID-19 and influenza (18/78 [23%] vs 8/39 [21%]; odds ratio, 1.16; 95% CI, 0.42-3.45; p = 0.82). The frequency of early microbiological testing and antibiotic use was similar between the two groups. Within the overall COVID-19 group, early bacterial coinfections were associated with a statistically significant increase in 30-day all-cause mortality (21/68 [30.9%] vs 40/221 [18.1%]; hazard ratio, 1.84; 95% CI, 1.01-3.32).

CONCLUSIONS AND RELEVANCE

Our data suggest similar rates of early bacterial coinfections in ICU patients with COVID-19 and influenza. In addition, early bacterial coinfections were significantly associated with an increased 30-day mortality in patients with COVID-19.

The under investigated facet of the COVID-19 pandemic: Molecular analysis of secondary bacterial infections at a COVID dedicated intensive care unit within a tertiary care center in Lebanon

Background

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. Secondary bacterial infections are associated with unfavorable outcomes in respiratory viral infections. This study aimed at determining the prevalence of secondary bacterial infections in COVID-19 patients admitted at a tertiary medical center in Lebanon.

Methodology

From May till November, 2020, a total of 26 Gram-negative isolates were recovered from 16 patients during the course of their COVID-19 infection with Escherichia coli being the most prevalent. The isolates were assessed for their antimicrobial susceptibility by broth microdilution against 19 antimicrobial agents from different classes. Whole genome sequencing of 13 isolates allowed the mining of antimicrobial resistance (AMR) determinants as well as mobile genetic elements and sequence types (ST). Finally, broth microdilution with three different efflux pump inhibitors [theobromine, conessine and PheArg-β-naphthylamide (PAβN)] was done.

Results

Antimicrobial susceptibility testing showed that out of the 26 Gram-negative isolates, 1 (4%) was extensively drug resistant and 14 (54%) were multi-drug resistant (MDR). Whole genome sequencing results revealed a plethora of AMR determinants among the 13 sequenced isolates. Moreover, the 9 Enterobacterales and 4 Pseudomonas aeruginosa sequenced isolates belonged to 9 and 2 different ST, respectively. Using a variety of efflux pump inhibitors we demonstrated that only PAβN had a significant effect when combined with levofloxacin, and the latter regained its activity against two P. aeruginosa isolates.

Conclusion

The identification of carbapenem and colistin resistant Gram-negative bacilli causing secondary bacterial infections in critical patients diagnosed with COVID-19 should be of high concern. Additionally, it is crucial to monitor and track AMR, post-COVID pandemic, in order to better understand the effect of this disease on AMR exacerbation.

Bacterial coinfection and antibiotic resistance in hospitalized COVID-19 patients: a systematic review and meta-analysis

Background

There were a few studies on bacterial coinfection in hospitalized COVID-19 patients worldwide. This systematic review aimed to provide the pooled prevalence of bacterial coinfection from published studies from 2020 to 2022.

Methods

Three databases were used to search the studies, and 49 studies from 2,451 identified studies involving 212,605 COVID-19 patients were included in this review.

Results

The random-effects inverse-variance model determined that the pooled prevalence of bacterial coinfection in hospitalized COVID-19 patients was 26.84% (95% CI [23.85-29.83]). The pooled prevalence of isolated bacteria for Acinetobacter baumannii was 23.25% (95% CI [19.27-27.24]), Escherichia coli was 10.51% (95% CI [8.90-12.12]), Klebsiella pneumoniae was 15.24% (95% CI [7.84-22.64]), Pseudomonas aeruginosa was 11.09% (95% CI [8.92-13.27]) and Staphylococcus aureus (11.59% (95% CI [9.71-13.46])). Meanwhile, the pooled prevalence of antibiotic-resistant bacteria for extended-spectrum beta-lactamases producing Enterobacteriaceae was 15.24% (95% CI [7.84-22.64]) followed by carbapenem-resistant Acinetobacter baumannii (14.55% (95% CI [9.59-19.52%])), carbapenem-resistant Pseudomonas aeruginosa (6.95% (95% CI [2.61-11.29])), methicillin-resistant Staphylococcus aureus (5.05% (95% CI [3.49-6.60])), carbapenem-resistant Enterobacteriaceae (4.95% (95% CI [3.10-6.79])), and vancomycin-resistant Enterococcus (1.26% (95% CI [0.46-2.05])).

Conclusion

All the prevalences were considered as low. However, effective management and prevention of the infection should be considered since these coinfections have a bad impact on the morbidity and mortality of patients.

Antibiotic Resistance during COVID-19: A Systematic Review

One of the public health issues faced worldwide is antibiotic resistance (AR). During the novel coronavirus (COVID-19) pandemic, AR has increased. Since some studies have stated AR has increased during the COVID-19 pandemic, and others have stated otherwise, this study aimed to explore this impact. Seven databases-PubMed, MEDLINE, EMBASE, Scopus, Cochrane, Web of Science, and CINAHL-were searched using related keywords to identify studies relevant to AR during COVID-19 published from December 2019 to May 2022, according to PRISMA guidelines. Twenty-three studies were included in this review, and the evidence showed that AR has increased during the COVID-19 pandemic. The most commonly reported resistant Gram-negative bacteria was Acinetobacterbaumannii, followed by Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. A. baumannii and K. pneumonia were highly resistant to tested antibiotics compared with E. coli and P. aeruginosa. Moreover, K. pneumonia showed high resistance to colistin. Commonly reported Gram-positive bacteria were Staphylococcus aureus and Enterococcus faecium. The resistance of E. faecium to ampicillin, erythromycin, and Ciprofloxacin was high. Self-antibiotic medication, empirical antibiotic administration, and antibiotics prescribed by general practitioners were the risk factors of high levels of AR during COVID-19. Antibiotics' prescription should be strictly implemented, relying on the Antimicrobial Stewardship Program (ASP) and guidelines from the World Health Organization (WHO) or Ministry of Health (MOH).

The impact of COVID-19 on antimicrobial prescription and drug resistance in fungi and bacteria

Secondary infections are one of the complications in COVID-19 patients. We aimed to analyze the antimicrobial prescriptions and their influence on drug resistance in fungi and bacteria isolated from severely ill COVID-19 patients. Seventy-nine severely ill COVID-19 hospitalized patients with secondary bacterial or fungal infections were included. We analyzed the prescribed antimicrobial regimen for these patients and the resistance profiles of bacterial and fungal isolates. In addition, the association between drug resistance and patients’ outcome was analyzed using correlation tests. The most prescribed antibacterial were ceftriaxone (90.7% of patients), vancomycin (86.0%), polymyxin B (74.4%), azithromycin (69.8%), and meropenem (67.4%). Micafungin and fluconazole were used by 22.2 and 11.1% of patients, respectively. Multidrug-resistant (MDR) infections were a common complication in severely ill COVID-19 patients in our cohort since resistant bacteria strains were isolated from 76.7% of the patients. Oxacillin resistance was observed in most Gram-positive bacteria, whereas carbapenem and cephalosporin resistance was detected in most Gram-negative strains. Azole resistance was identified among C. glabrata and C. tropicalis isolates. Patients who used more antimicrobials stayed hospitalized longer than the others. The patient’s age and the number of antibacterial agents used were associated with the resistance phenotype. The susceptibility profile of isolates obtained from severely ill COVID-19 patients highlighted the importance of taking microbial resistance into account when managing these patients. The continuous surveillance of resistant/MDR infection and the rational use of antimicrobials are of utmost importance, especially for long-term hospitalized patients with COVID-19.

Translational in vitro and in vivo PKPD modelling for apramycin against Gram-negative lung pathogens to facilitate prediction of human efficacious dose in pneumonia

OBJECTIVES

New drugs and methods to efficiently fight carbapenem-resistant Gram-negative pathogens are sorely needed. In this study we characterized the preclinical pharmacokinetics and pharmacodynamics of the clinical-stage drug candidate apramycin in time kill and mouse lung infection models. Based on in vitro and in vivo data, we developed a mathematical model to predict human efficacy.

METHODS

Three pneumonia-inducing Gram-negative species Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were studied. Bactericidal kinetics were evaluated with time-kill curves; in vivo pharmacokinetics were studied in healthy and infected mice, with sampling in plasma and epithelial lining fluid after subcutaneous administration; in vivo efficacy was measured in a neutropenic mouse pneumonia model. A pharmacokinetic-pharmacodynamic model, integrating all the data, was developed and simulations were performed.

RESULTS

Good lung penetration of apramycin in epithelial lining fluid (ELF) was shown (AUC_ELF/AUC_plasma = 88%). Plasma clearance was 48% lower in lung infected mice compared to healthy mice. For two out of five strains studied, a delay in growth (∼5h) was observed in vivo but not in vitro. The mathematical model enabled integration of lung pharmacokinetics to drive mouse PKPD. Simulations predicted that 30 mg/kg of apramycin once daily would result in bacteriostasis in patients.

CONCLUSION

Apramycin is a candidate for treatment of carbapenem-resistant Gram-negative pneumonia as demonstrated in an integrated modeling framework for three bacterial species. We show that mathematical modelling is a useful tool for simultaneous inclusion of multiple data sources, notably plasma and lung in vivo PK and simulation of expected scenarios in a clinical setting, notably lung infections.

Pseudomonas aeruginosa modulates alginate biosynthesis and type VI secretion system in two critically ill COVID-19 patients

Background

COVID-19 pneumonia has caused huge impact on the health of infected patients and associated with high morbidity and mortality. Shift in the lung microbial ecology upon such viral infection often worsens the disease and increases host susceptibility to superinfections. Bacterial superinfection contributes to the aggravation of COVID-19 and poses a great challenge to clinical treatments. An in-depth investigation on superinfecting bacteria in COVID-19 patients might facilitate understanding of lung microenvironment post virus infections and superinfection mechanism.

Results

We analyzed the adaptation of two pairs of P. aeruginosa strains with the same MLST type isolated from two critical COVID-19 patients by combining sequencing analysis and phenotypic assays. Both P. aeruginosa strains were found to turn on alginate biosynthesis and attenuate type VI secretion system (T6SS) during short-term colonization in the COVID-19 patients, which results in excessive biofilm formation and virulence reduction-two distinct markers for chronic infections. The macrophage cytotoxicity test and intracellular reactive oxygen species measurement confirmed that the adapted P. aeruginosa strains reduced their virulence towards host cells and are better to escape from host immune clearance than their ancestors.

Conclusion

Our study suggests that SARS-CoV-2 infection can create a lung environment that allow rapid adaptive evolution of bacterial pathogens with genetic traits suitable for chronic infections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00748-z.

The rise in antimicrobial resistance: An obscure issue in COVID-19 treatment

A saturated health care system with a lack of evidence-based antiviral medicine and ignorance of antimicrobial stewardship during pandemics has prompted clinicians to prescribe a broad-spectrum antibiotic more often. A prospective, cross-sectional study of COVID-infected patients was conducted to gain insight into antibiotic prescribing practices and their impact on antimicrobial resistance. The antibiotic susceptibility test was performed using the disc diffusion method. 318 patients met the study's inclusion criteria, with a mean age of 46 years and 55% (175) of them being males. Antibiotics were prescribed for 93.72% (209) of mild cases, 92.45% (49) of moderate cases, 96.15% (25) of severe cases, and 100% (16) of critical cases of COVID-19. A total of 95 samples were sent in for culture and antibiotic sensitivity testing, with 58.95% (56) confirming growth. The majority of the growth was found to contain E. coli (14). In 54.9% of cases, antibiotics with less than 50% sensitivity to curing bacterial infection were detected. In the study, we found that antibiotics were being used unnecessarily in excessive quantities and that more than half of the antibiotics were less sensitive to isolated bacteria.