Prevalence of multidrug-resistant Gram-negative bacteria from blood cultures and rapid detection of beta-lactamase-encoding genes by multiplex PCR assay

Introduction This study aimed to determine the prevalence of multidrug-resistant Gram-negative bacteria (GNB) from blood cultures in a tertiary-care hospital and the multiplex PCR assay's ability to detect resistance genes. Methods A total of 388 GNB isolates obtained from hospitalized patients between November 2019 and November 2021 were included in the study. Antimicrobial susceptibility testing was done by VITEK 2 system and broth microdilution method. Beta-lactamase-encoding genes were detected by multiplex PCR assays, BioFire-Blood Culture Identification 2 (BCID2) panel (bioMerieux, France). Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically with VITEK AST-GN71 card (bioMerieux, France). The isolates of GNB were classified into multidrug-resistant, extensively-drug-resistant, and pandrug-resistant categories, and their prevalence and distribution in different wards, including coronavirus diseases 2019 (COVID-19) intensive care units (ICU), were calculated. Results Results revealed that all isolates of Acinetobacter baumannii and Pseudomonas aeruginosa were multidrug-resistant as well as 91.6% of Enterobacter cloacae, 80.6% of Proteus mirabilis, and 76.1% of Klebsiella pneumoniae, respectively. In fermentative bacteria, blaOXA-48-like (58.1%), blaNDM (16.1%), blaKPC (9.7%) and blaVIM (6.5%) genes were detected. More than half of Enterobacter cloacae (58.3%) and Klebsiella pneumoniae (53.7%) produced ESBLs. Among non-fermenters, the blaNDM gene was carried by 55% of Pseudomonas aeruginosa and 19.5% of Acinetobacter baumannii. In the COVID-19 ICU, Acinetobacter baumannii was the most common isolate (86.1%). Conclusions This study revealed high proportions of multidrug-resistant blood isolates and various underlying resistance genes in Gram-negative strains. The BCID2 panel seems to be helpful for the detection of the most prevalent resistance genes of fermentative bacteria.Copyright © GERMS 2022.

Emergence and Spread of Enterobacterales with Multiple Carbapenemases after COVID-19 Pandemic.

Resistance to carbapenems in Enterobacterales has become a matter of the highest concern in the last decade. Recently, Enterobacterales harboring multiple carbapenemases were detected in three hospital centers in Croatia and in the outpatient setting, posing a serious therapeutic challenge for clinicians. In this study, we analyzed eight Klebsiella pneumoniae and two Enterobacter cloacae complex isolates with multiple carbapenemases, with regard to antibiotic susceptibility, ß-lactamase production and plasmid content. The isolates demonstrated uniform resistance to amoxicillin/clavulanate, piperacillin/tazobactam, cefuroxime, ceftazidime, cefotaxime, ceftriaxone and ertapenem. Among novel ß-lactam/inhibitor combinations, ceftazidime/avibactam exhibited moderate activity, with 50% of isolates susceptible. All isolates demonstrated resistance to imipenem/cilastatin/relebactam, and all but one to ceftolozane/tazobactam. Four isolates exhibited a multidrug-resistant phenotype (MDR), whereas six were allocated to an extensively drug-resistant phenotype (XDR). OKNV detected three combinations of carbapenemases: OXA-48+NDM (five isolates), OXA-48+VIM (three isolates) and OXA-48+KPC (two isolates). Inter-array testing identified a wide variety of resistance genes for ß-lactam antibiotics: blaCTX-M-15, blaTEM, blaSHV, blaOXA-1, blaOXA-2, blaOXA-9, aminoglycosides: aac6, aad, rmt, arm and aph, fluoroquinolones: qnrA, qnrB and qnrS, sulphonamides: sul1 and sul2 and trimethoprim: dfrA5, dfrA7, dfrA14, dfrA17 and dfrA19. mcr genes were reported for the first time in Croatia. This study demonstrated the ability of K. pneumoniae and E. cloacae to acquire various resistance determinants under the selection pressure of antibiotics widely used during the COVID-19 pandemic. The novel inter-array method showed good correlation with OKNV and PCR, although some discrepancies were found.

Antibiotic resistance of Klebsiella pneumoniae against the background of the COVID-19 pandemic: experience of the multidisciplinary hospital

Frequency of bacterial co-infections among patients with COVID-19 is not high, and over-prescribing of antibiotics may contribute the selection of resistant strains of enterobacteria and gram-negative non-fermenting bacteria. The aim of the study was to assess the local features of antibiotic resistance of K. pneumoniae and its genetic mechanisms against background of the COVID-19 infection pandemic. Material and methods. There was selected 37 carbapenem-resistant K. pneumoniae strains isolated in 2016, 2017 and 2020 from hospitalized patients, including 15 strains, isolated from patients with COVID-19 infection. Minimal inhibitory concentrations (MICs) of meropenem and colistin were determined by broth microdilution method. Determination of MICs of eravacycline, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam was performed using Sensititre diagnostic system on EUMDROXF plates. Susceptibility to 11 combinations of 2 antibiotics was detected by modified method of multiply combination bactericidal testing. For 4 K. pneumoniae strains high-throughput sequencing was performed, followed with the subsequent search for determinants of antibiotic resistance and virulence, assessment of plasmid profiles. Results. All strains were resistant to meropenem (MIC50 32 mg/l, MIC90 128 mg/l) and produced KPC and OXA-48 carbapenemases. Strains isolated in 2016-2017 were susceptible to colistin (MIC <=2 mg/l), in 2020 only 26.7% of the strains retained their susceptibility (MIC50 64 mg/l, MIC90 256 mg/l). Susceptibility to combinations of two antibiotics with colistin included reduced from 84.6-100% in 2016-2017 till 26.6-66.7% in 2020. The strains isolated in 2020 retained their susceptibility to ceftazidime/avibactam (MIC <=1 mg/l). 5 strains resistant to cefiderocol with a MIC 8 mg/l were identified. Strains 2564 and 3125 isolated in 2020 from sputum of patients with COVID-19 infection belonged to different sequence-types (ST12 and ST23) and contained the blaOXA-48 carbapenemase gene, additionally strain 2564 contained the blaKPC-27carbapenemase gene. Resistance to colistin was caused by inactivation of the mgrB genes due to insertion of IS1 and IS5-like transposons. Conclusion. The performed genetic studies demonstrate a diversity of mechanisms of antibiotic resistance in K. pneumoniae leading to the formation of resistance including to antibiotics that haven't been used in Belarus till now.Copyright © 2021 Geotar Media Publishing Group. All Rights Reserved.

Activity of Cefiderocol and Other New Antibiotics Against Extensively Drug-Resistant Klebsiella pneumoniae Strains.

Background. The spread of extensive drug-resistance among gram-negative bacteria calls for the search for antimicrobics with new mechanisms of actions. The aim was to assess susceptibility of extensively drug-resistant K.pneumoniae strains to cefiderocol and other new inhibitor-protected beta-lactams, and to determine genetic mechanisms of antibiotic resistance. Methods. This study included 30 extensively drug-resistant K.pneumoniae strains collected in 2016-2021 from 4 regions of Belarus. Carbapenemase genes were detected by real-time PCR. Minimum inhibitory concentrations (MICs) for cefiderocol and other new antibiotics were assessed by microdilution method using the Sensititre system. Whole genome sequencing was performed for 2 resistant and 3 cefiderocol-susceptible strains. Genome assemblies and annotation were performed using UGENE v. 37.0 software. Nucleotide sequences were translated using CLC Sequence Viewer v. 8.0 (QIAGEN) package. The PROVEAN software was used to assess amino asides substitutions and their influence on the functional activity of proteins. Results. KPC carbapenemase-producers were 4 strains, OXA-48 - 17, KPC+OXA-48 - 1, NDM - 7, OXA-48 + NDM - 1. All KPC-producers were susceptible to imipenem/relebactam and meropenem/vaborbactam. Resistance to ceftazidime-avibactam was noted in all NDM producers and OXA-48+NDM co-producer. The study has identified 9 cefiderocol-resistant strains. These were NDM and OXA-48-producers isolated from hospitalized patients with COVID-19 infection from 3 regions of Belarus. Resistant strains had functionally significant nonsynonymous substitutions in the genes of TonB-dependent receptors for catecholate siderophores FepA (F472V, P64S) and Fiu (T92S). Conclusion. The study has shown high efficacy of new inhibitor-protected carbapenems and cephalosporins against certain types of carbapenemase-producers. Strains with mutational resistance to cefiderocol, an antibiotic not previously used in Belarus, have been identified.Copyright © Team of Authors, 2022.

Activity of Cefiderocol and Other New Antibiotics Against Extensively Drug-Resistant Klebsiella pneumoniae Strains

Background. The spread of extensive drug-resistance among gram-negative bacteria calls for the search for antimicrobics with new mechanisms of actions. The aim was to assess susceptibility of extensively drug-resistant K.pneumoniae strains to cefiderocol and other new inhibitor-protected β-lactams, and to determine genetic mechanisms of antibiotic resistance. Methods. This study included 30 extensively drug-resistant K.pneumoniae strains collected in 2016–2021 from 4 regions of Belarus. Carbapenemase genes were detected by real-time PCR. Minimum inhibitory concentrations (MICs) for cefiderocol and other new antibiotics were assessed by microdilution method using the Sensititre system. Whole genome sequencing was performed for 2 resistant and 3 cefiderocol-susceptible strains. Genome assemblies and annotation were performed using UGENE v. 37.0 software. Nucleotide sequences were translated using CLC Sequence Viewer v. 8.0 (QIAGEN) package. The PROVEAN software was used to assess amino asides substitutions and their influence on the functional activity of proteins. Results. KPC carbapenemase-producers were 4 strains, OXA-48 — 17, KPC+OXA-48 — 1, NDM — 7, OXA-48 + NDM — 1. All KPC-producers were susceptible to imipenem/relebactam and meropenem/vaborbactam. Resistance to ceftazidime-avibactam was noted in all NDM producers and OXA-48+NDM co-producer. The study has identified 9 cefiderocol-resistant strains. These were NDM and OXA-48-producers isolated from hospitalized patients with COVID-19 infection from 3 regions of Belarus. Resistant strains had functionally significant nonsynonymous substitutions in the genes of TonB-dependent receptors for catecholate siderophores FepA (F472V, P64S) and Fiu (T92S). Conclusion. The study has shown high efficacy of new inhibitor-protected carbapenems and cephalosporins against certain types of carbapenemase-producers. Strains with mutational resistance to cefiderocol, an antibiotic not previously used in Belarus, have been identified. © Team of Authors, 2022.

Ceftazidime-Avibactam (C/A) Resistant, Meropenem Sensitive KPC-Producing Klebsiella pneumoniae in ICU Setting: We Are What We Are Treated with?

The continuous spread of carbapenem-resistant Klebsiella pneumoniae (CP-Kp) strains presents a severe challenge to the healthcare system due to limited therapeutic options and high mortality. Since its availability, ceftazidime/avibactam (C/A) has become a first-line option against KPC-Kp, but C/A-resistant strains have been reported increasingly, especially with pneumonia or prior suboptimal blood exposure to C/A treatment. A retrospective, observational study was conducted with all patients admitted to the Intensive Care Unit (ICU) dedicated to COVID-19 patients at the City of Health & Sciences in Turin, between 1 May 2021 and 31 January 2022, with the primary endpoint to study strains with resistance to C/A, and secondly to describe the characteristics of this population, with or without previous exposure to C/A. Seventeen patients with colonization or invasive infection due to Klebsiella pneumoniae, C/A resistance, and susceptibility to meropenem (MIC = 2 µg/L) were included; the blaKPC genotype was detected in all isolates revealing D179Y mutation in the blaKPC-2 (blaKPC-33) gene. Cluster analysis showed that 16 out of the 17 C/A-resistant KPC-Kp isolates belonged to a single clone. Thirteen strains (76.5%) were isolated in a 60-day period. Only some patients had a previous infection with non-mutant KPC at other sites (5; 29.4%). Eight patients (47.1%) underwent previous large-spectrum antibiotic treatment, and four patients (23.5%) had prior treatment with C/A. The secondary spread of the D179Y mutation in the blaKPC-2 during the COVID-19 pandemic needs to be addressed constantly by an interdisciplinary interaction between microbiologists, infection control personnel, clinicians, and infectious diseases consultants to properly diagnose and treat patients.

Carbapenemase-Producing Klebsiella pneumoniae in COVID-19 Intensive Care Patients: Identification of IncL-VIM-1 Plasmid in Previously Non-Predominant Sequence Types.

During the COVID-19 pandemic, intensive care units (ICUs) operated at or above capacity, and the number of ICU patients coinfected by nosocomial microorganisms increased. Here, we characterize the population structure and resistance mechanisms of carbapenemase-producing Klebsiella pneumoniae (CP-Kpn) from COVID-19 ICU patients and compare them to pre-pandemic populations of CP-Kpn. We analyzed 84 CP-Kpn isolates obtained during the pandemic and 74 CP-Kpn isolates obtained during the pre-pandemic period (2019) by whole genome sequencing, core genome multilocus sequence typing, plasmid reconstruction, and antibiotic susceptibility tests. More CP-Kpn COVID-19 isolates produced OXA-48 (60/84, 71.4%) and VIM-1 (18/84, 21.4%) than KPC (8/84, 9.5%). Fewer pre-pandemic CP-Kpn isolates produced VIM-1 (7/74, 9.5%). Cefiderocol (97.3-100%) and plazomicin (97.5-100%) had the highest antibiotic activity against pandemic and pre-pandemic isolates. Sequence type 307 (ST307) was the most widely distributed ST in both groups. VIM-1-producing isolates belonging to ST307, ST17, ST321 and ST485, (STs infrequently associated to VIM-1) were detected during the COVID-19 period. Class 1 integron Int1-blaVIM-1-aac(6')-1b-dfrB1-aadAI-catB2-qacEΔ1/sul1, found on an IncL plasmid of approximately 70,000 bp, carried blaVIM-1 in ST307, ST17, ST485, and ST321 isolates. Thus, CP-Kpn populations from pandemic and pre-pandemic periods have similarities. However, VIM-1 isolates associated with atypical STs increased during the pandemic, which warrants additional monitoring and surveillance.

Outbreak of Klebsiella pneumoniae ST11 Resistant To Ceftazidime-Avibactam Producing KPC-31 and the Novel Variant KPC-115 during COVID-19 Pandemic in Argentina.

We describe an outbreak of Klebsiella pneumoniae sequence type 11 (ST11) producing KPC variants resistant to ceftazidime-avibactam. Six patients hospitalized in the intensive care unit (mostly due to critical COVID pneumonia) presented infection or colonization by this bacterium. They had several comorbidities and required mechanical ventilation, central venous catheters, and urinary catheters. All 6 patients had a history of fecal colonization with KPC-producing Enterobacterales (KPC-E). Three of them had previous episodes of infection with ceftazidime-avibactam-susceptible KPC-producing K. pneumoniae, which were treated with ceftazidime-avibactam. Several phenotypic methods failed to detect carbapenemase production in these 6 ceftazidime-avibactam-resistant isolates, and they showed in vitro susceptibility to imipenem and meropenem. All of them rendered positive results for blaKPC by PCR, and amplicon sequencing identified blaKPC-31 variant in 5 isolates and a novel variant, named blaKPC-115, in the other. Moreover, matrix-assisted laser desorption ionization-time of flight mass spectrometry was able to detect KPC in all isolates. Ceftazidime-avibactam-resistant isolates, as well as those recovered from previous infection episodes (KPC-3-producing K. pneumoniae, ceftazidime-avibactam susceptible), displayed a unique pulse type and belonged to ST11. Based on whole-genome sequencing results of selected isolates, less than 7 single-nucleotide polymorphisms were identified among them, which was indicative of the presence of a unique clone. Both in vivo selection and horizontal transmission seemed to have occurred in our hospital. Detection of these strains is challenging for the laboratory. History of previous KPC-E infections or colonization and systematic testing for resistance to ceftazidime-avibactam might help raise awareness of this possibility. IMPORTANCE Klebsiella pneumoniae is one of the main bacteria that cause infections in health care settings. This pathogen has developed a high level of resistance to many antibiotics. Some K. pneumoniae isolates can produce an enzyme known as carbapenemase KPC, making carbapenems (considered the last line for therapy) not effective to treat their infections. The combination ceftazidime-avibactam, approved by FDA in 2015, is useful to treat infections caused by KPC-producing K. pneumoniae. This study describes the emergence, in one hospital in Argentina, of K. pneumoniae isolates that produce KPC variants (KPC-31 and KPC-115) resistant to ceftazidime-avibactam. The ceftazidime-avibactam-resistant bacteria were isolated in inpatients, including some that previously received this combination as treatment. Transmission of this strain to other patients also occurred in the studied period. Detection of these bacteria is challenging for the laboratory. The knowledge and awareness of the emergence of this pathogen in our region are highly valuable.

Dissemination of High-Risk Clones Enterobacterales among Bulgarian Fecal Carriage Isolates.

The gastrointestinal tract is an important reservoir of high-risk Enterobacteria clones and a driver of antimicrobial resistance in hospitals. In this study, patients from six hospitals in four major Bulgarian towns were included in this study. Overall, 205 cefotaxime-resistant isolates (35.3%) of Enterobacterales order were detected in fecal samples among 580 patients during the period of 2017-2019. ESBL/carbapenemase/plasmidic AmpC producer rates were 28.8%, 2.4%, and 1.2%, respectively. A wide variety of ESBLs: CTX-M-15 (41%), CTX-M-3 (24%), CTX-M-27 (11%), and CTX-M-14 (4%) was found. The carbapenemases identified in this study were New Delhi metalo-ß-lactamase (NDM)-1 (5.4%) and Klebsiella carbapenemase (KPC)-2 (1.5%). Most NDM-1 isolates also produced CTX-M-15/-3 and CMY-4 ß-lactamases. They belonged to ST11 Klebsiella pneumoniae clone. The epidemiology typing revealed three main high-risk K. pneumoniae clones (26%)-ST11, ST258, and ST15 and five main Escherichia coli clones-ST131 (41.7%), ST38, ST95, ST405, and ST69. Sixty-one percent of ST131 isolates were from the highly virulent epidemic clone O25b:H4-ST131. Phylotyping revealed that 69% of E. coli isolates belonged to the virulent B2 and D groups. Almost all (15/16) Enterobacter isolates were identified as E. hormaechei and the most common ST type was ST90. Among all of the isolates, a high ESBL/carbapenemases/plasmid AmpC (32.4%) prevalence was observed. A significant proportion of the isolates (37%) were members of high-risk clones including two pan-drug-resistant K. pneumoniae ST11 NDM-1 producing isolates. Due to extensive antibiotic usage during COVID-19, the situation may worsen, so routine screenings and strict infection control measures should be widely implemented.

Aetiology and antibiotic susceptibility pattern of bacterial pathogens in respiratory specimens of COVID-19 patients on respiratory support: A tertiary care hospital study

Objective: To describe aetiology and antibiotic susceptibility pattern of bacterial pathogens in respiratory specimens of covid-19 patients on respiratory support in tertiary care hospital of Lahore. Study Design: Descriptive study. Setting: Microbiology Department, CMH, Lahore. Period: May 2021 to October 2021. Material & Methods: A total 107 isolates from 145 patients who were COVID-19 positive and on respiratory support were included in the study. Bacterial isolates were isolated from clinical samples according to standard protocol of culturing and incubation. Antibiotic sensitivity, carbapenamase detection was done according to CLSI 2021. Molecular identification of carbapenem resistant genes blaIMP and blaVIM was determined by PCR. Results: A total of 107 bacterial isolates were isolated from clinical specimens. A. baumannii was the most common isolated organism. Colistin and aminoglycosides were found to be the most effective antibiotics. Among carbapenem resistant isolates 89.5% were MHT positive and among these 59 (86.8%) were MBL positive. Among MBL positive isolates, 5.61% and 29.91% were positive for blaIMP and blaVIM respectively. Conclusion: Patients admitted for COVID-19 treatment are at higher risk of acquisition of secondary bacterial infections and antibiotic resistance among such pathogens is at alarming. [ FROM AUTHOR] Copyright of Professional Medical Journal is the property of Professional Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

The Role of Efflux Pump and Carbapenemase Production in the Development of Multidrug Resistance in Klebsiella Pneumoniae and Acinetobacter Baumannii Strains Isolated from Patients with COVID-19 Infection

Introduction. Patients hospitalized with COVID-19 are often prescribed broad-spectrum antibiotics that can contribute the selection and spread of antibiotic-resistant strains. Purpose. To identify carbapenemase production and the active efflux mechanisms for antibiotics of various classes in multidrug-and extensively drug-resistant Klebsiella pneumoniae and Acinetobacter baumannii strains isolated from patients with COVID-19 infection. Materials and methods. This study included 51 multidrug-and extensively drug-resistant Klebsiella pneumoniae strains and 47 multidrug-resistant strains of Acinetobacter baumannii isolated from patients with COVID-19 infection. The minimum inhibitory concentrations (MICs) for meropenem, imipenem, cefepime, ceftazidime, doxycycline, levofloxacin, tigecycline, rifampicin, chloramphenicol and amikacin were assessed by broth microdilution method for all investigated strains. Moreover, MICs of antibiotics in the presence of efflux pump inhibitor (carbonyl cyanide-chlorophenylhydrazone, CCCP) were determined. For phenotypic detection of metallo-β-lactamase (MBL) production the double-disk EDTA method was performed. Carbapenemase genes were detected by real-time PCR. Results. All of the isolated strains have demonstrated multidrug or extensively drug resistance. All strains of A.baumannii were resistant to carbapenems, levofloxacin, amikacin and were OXA-carbapenemase producers. Susceptibility to carbapenems remained only in 2.0–3.9% of K. pneumoniae strains, to amikacin – in 7.8% of strains. Carbapenemase production was detected in 68.6% of K. pneumoniae strains (NDM – 31.4%, OXA-48 – 23.5%, KPC – 2.0%, co-production of two carbapenemase – 11.8%). Inhibition of efflux pumps made it possible to reduce the MIC values for carbapenems, cephalosporins, levofloxacin, amikacin, tigecycline in 2.1–25.5% of A. baumannii and K. pneumoniae strains. On the other hand, it didn’t restore their susceptibility to antibiotics. Conclusion. Resistance to carbapenems and other β-lactams in A.baumannii and K. pneumoniae strains is associated with the production of carbapenemases. The presence of efflux mechanisms in some of the studied strains is an important, but not the only mechanism of antibiotic resistance. © 2022, Professionalnye Izdaniya. All rights reserved.

Genomic Analysis of a Highly Virulent NDM-1-Producing Escherichia coli ST162 Infecting a Pygmy Sperm Whale (Kogia breviceps) in South America.

Carbapenemase-producing Enterobacterales are rapidly spreading and adapting to different environments beyond hospital settings. During COVID-19 lockdown, a carbapenem-resistant NDM-1-positive Escherichia coli isolate (BA01 strain) was recovered from a pygmy sperm whale (Kogia breviceps), which was found stranded on the southern coast of Brazil. BA01 strain belonged to the global sequence type (ST) 162 and carried the bla NDM-1, besides other medically important antimicrobial resistance genes. Additionally, genes associated with resistance to heavy metals, biocides, and glyphosate were also detected. Halophilic behavior (tolerance to > 10% NaCl) of BA01 strain was confirmed by tolerance tests of NaCl minimal inhibitory concentration, whereas halotolerance associated genes katE and nhaA, which encodes for catalase and Na+/H+ antiporter cytoplasmic membrane, respectively, were in silico confirmed. Phylogenomics clustered BA01 with poultry- and human-associated ST162 lineages circulating in European and Asian countries. Important virulence genes, including the astA (a gene encoding an enterotoxin associated with human and animal infections) were detected, whereas in vivo experiments using the Galleria mellonella infection model confirmed the virulent behavior of the BA01 strain. WHO critical priority carbapenemase-producing pathogens in coastal water are an emerging threat that deserves the urgent need to assess the role of the aquatic environment in its global epidemiology.

Carbapenem-resistant Klebsiella pneumoniae outbreak in a COVID-19 intensive care unit; a case-control study.

We analysed a carbapenem-resistant Klebsiella pneumoniae (CRKP) outbreak in the coronavirus disease (COVID) ICU. We retrospectively collected data from ICU records. We identified 25 cases between 12 November 2020 and 19 December 2020, and compared them to 42 controls present in the ICU during the same period. The presence of a femoral haemodialysis catheter was strongly associated with invasive CRKP infections (cases, 9 [36%]; controls, 0 [0%]; odds ratio [OR] 95% confidence intervals [CIs], 21 (5; 89)). We found a significant association between old age and CRKP infection with adverse outcomes. Sequence analysis revealed three distinct carbapenemase genes: blaNDM-1, blaOXA-48 and blaKPC-2. We launched rectal swab sampling upon admission to the ICU, cohorted colonized patients and cases and conducted an intensive training programme for newly employed staff. This study revealed that the emergence and dissemination of CRKP in COVID ICUs were associated with increased adverse outcomes. The presence of a femoral haemodialysis catheter was a significant risk factor for CRKP infections.

The Collateral Effects of COVID-19 Pandemic on the Status of Carbapenemase-Producing Pathogens.

The serious challenge of antimicrobial resistance continues to threaten public health and lingers in the era of the coronavirus disease 2019 (COVID-19), declared pandemic by the World Health Organization. While the pandemic has triggered the importance of infection control practices and preventive measures such as physical distancing, hand hygiene, travel reduction and quarantine, the ongoing alarm of antimicrobial resistance seems to accompany the pandemic too. Antimicrobial resistance has been fostered during COVID-19, possibly due to high rate of empirical antibiotic utilization in COVID-19 patients, increased use of biocides, and the disruption of proper healthcare for other conditions. Specifically, carbapenemase-producing Gram-negative bacteria have shown to cause secondary bacterial infections in patients hospitalized for COVID-19. Clinical and microbiological evidence of such infections is accumulating in different parts of the world. With the resilient nature of carbapenemases, their association with mortality, and the limited treatment options available, concerns regarding this group of antibiotic-hydrolyzing enzymes during the pandemic are expected to upsurge. While the additional burden carbapenemases exert on healthcare is worrisome, it remains hidden or abandoned among the various health consequences of the pandemic. The purpose of this minireview is to shed a light on carbapenemase-associated infections during such unprecedented time of COVID-19. A focused insight shall be made into carbapenemases, their implications for COVID-19 patients, and the features and consequences of co-infection, with a review of available evidence from pertinent literature. The importance of increased surveillance for carbapenemase-producers and optimizing their management in relation to the pandemic, shall be addressed as well.

Comparative Evaluation of Phenotypic Synergy Tests versus RESIST-4 O.K.N.V. and NG Test Carba 5 Lateral Flow Immunoassays for the Detection and Differentiation of Carbapenemases in Enterobacterales and Pseudomonas aeruginosa.

The spread of carbapenem-resistant Pseudomonas aeruginosa and carbapenemase-producing Enterobacterales (CPE) has dramatically impacted morbidity and mortality. COVID-19 pandemic has favored the selection of these microorganisms because of the excessive and prolonged use of broad-spectrum antibiotics and the outbreaks related to patient transfer between hospitals and inadequate personal protective equipment. Therefore, early CPE detection is considered essential for their control. We aimed to compare conventional phenotypic synergy tests and two lateral flow immunoassays for detecting carbapenemases in Enterobacterales and P. aeruginosa. We analyzed 100 carbapenem-resistant Gram-negative bacilli isolates, 80 Enterobacterales, and 20 P. aeruginosa (86 isolates producing KPC, NDM, OXA-48, IMP, and VIM carbapenemases and 14 non-carbapenemase-producing isolates). We performed a modified Hodge test, boronic acid and ethylenediaminetetraacetic acid (EDTA) synergy tests, and two lateral flow immunoassays: RESIST-4 O.K.N.V. (Coris Bioconcept) and NG Test Carba 5 (NG Biotech). In total, 76 KPC, seven VIM, one NDM, one OXA-48, and one isolate coproducing KPC + NDM enzymes were included. The concordance of different methods estimated by the Kappa index was 0.432 (standard error: 0.117), thus showing a high variability with the synergy tests with boronic acid and EDTA and reporting 16 false negatives that were detected by the two immunochromatographic methods. Co-production was only detected using immunoassays. Conventional phenotypic synergy tests with boronic acid and EDTA for detecting carbapenemases are suboptimal, and their routine use should be reconsidered. These tests depend on the degree of enzyme expression and the distance between disks. Lateral flow immunoassay tests are a rapid and cost-effective tool to detect and differentiate carbapenemases, improving clinical outcomes through targeted therapy and promoting infection prevention measures. IMPORTANCE Infections due to multidrug-resistant pathogens are a growing problem worldwide. The production of carbapenemases in Pseudomonas aeruginosa and Enterobacterales cause a high impact on the mortality of infected patients. Therefore, it is of great importance to have methods that allow the early detection of these multi-resistant microorganisms, achieving the confirmation of the type of carbapenemase present, with high sensitivity and specificity, with the aim of improving epidemiological control, dissemination, the clinical course to through targeted antibiotic therapy and promoting infection control in hospitals.

A Study in a Regional Hospital of a Mid-Sized Spanish City Indicates a Major Increase in Infection/Colonization by Carbapenem-Resistant Bacteria, Coinciding with the COVID-19 Pandemic.

Bacterial resistance to antibiotics has proven difficult to control over the past few decades. The large group of multidrug-resistant bacteria includes carbapenemase-producing bacteria (CPB), for which limited therapeutic options and infection control measures are available. Furthermore, carbapenemases associate with high-risk clones that are defined by the sequence type (ST) to which each bacterium belongs. The objectives of this cross-sectional and retrospective study were to describe the CPB population isolated in a third-level hospital in Southern Spain between 2015 and 2020 and to establish the relationship between the ST and the epidemiological situation defined by the hospital. CPB were microbiologically studied in all rectal and pharyngeal swabs and clinical samples received between January 2015 and December 2020, characterizing isolates using MicroScan and mass spectrometry. Carbapenemases were detected by PCR and Sanger sequencing, and STs were assigned by multilocus sequence typing (MLST). Isolates were genetically related by pulsed-field gel electrophoresis using Xbal, Spel, or Apal enzymes. The episodes in which each CPB was isolated were recorded and classified as involved or non-involved in an outbreak. There were 320 episodes with CPB during the study period: 18 with K. pneumoniae, 14 with Klebisella oxytoca, 9 with Citrobacter freundii, 11 with Escherichia coli, 46 with Enterobacter cloacae, 70 with Acinetobacter baumannii, and 52 with Pseudomonas aeruginosa. The carbapenemase groups detected were OXA, VIM, KPC, and NDM with various subgroups. Synchronous relationships were notified between episodes of K. pneumoniae and outbreaks for ST15, ST258, ST307, and ST45, but not for the other CPB. There was a major increase in infections with CPB over the years, most notably during 2020, coinciding with the COVID-19 pandemic. This study highlights the usefulness of gene sequencing techniques to control the spread of these microorganisms, especially in healthcare centers. These techniques offer faster results, and a reduction in their cost may make their real-time application more feasible. The combination of epidemiological data with real-time molecular sequencing techniques can provide a major advance in the transmission control of these CPB and in the management of infected patients. Real-time sequencing is essential to increase precision and thereby control outbreaks and target infection prevention measures in a more effective manner.

Fecal Carriage and Epidemiology of Extended-Spectrum Beta-Lactamase/Carbapenemases Producing Enterobacterales Isolates in Bulgarian Hospitals.

The gastrointestinal tract is an important reservoir of extended spectrum beta-lactamase (ESBL)/carbapenemase-producing Enterobacterales isolates. This study included patients from two Bulgarian hospitals. Overall, 98 ESBL producers (including 68 Escherichia coli and 20 Klebsiella pneumoniae isolates) were detected among 99 hospitalized patients, 212 patients at admission, and 92 hospital staff in 42.4%, 24.5%, and 4%, respectively. We observed blaCTX-M-15 in 47% of isolates, blaCTX-M-3 in 39% and blaCTX-M-14 in 11%. Three blaCTX-M-15 positive isolates were also blaKPC-2 positive. High transferability was detected for blaCTX-M-3 carrying plasmids (55%) with L/M and I1 replicon plasmids, followed by CTX-M-14 (36.4%) and CTX-M-15 (27.9%) with IncF plasmids. BlaKPC-2 was carried by FIIAs plasmids. Epidemiology typing revealed 8 K. pneumoniae ST types-ST15(8/20), ST17(4/20), ST37(2/20) and 9 E. coli ST types-ST131 (30.9%, 21/68), ST38 (8/68), ST95(7/68) and ST316(7/68). All ST131 isolates but one was from the highly virulent epidemic clone O25bST131. This is the first report in Bulgaria about ESBL/carbapenemase faecal carriage. We observed high ESBL/carbapenemases prevalence. A predominant number of isolates were members of highly epidemic and virulent PanEuropean clones ST15 K. pneumoniae and O25bST131 E. coli. High antibiotics usage during the COVID pandemic will worsen the situation. Routine screenings and strict infection control measures should be widely implemented.

Molecular Epidemiology of Carbapenemases in Enterobacteriales from Humans, Animals, Food and the Environment.

The Enterobacteriales order consists of seven families including Enterobacteriaceae, Erwiniaceae, Pectobacteriaceae, Yersiniaceae, Hafniaceae, Morganellaceae, and Budviciaceae and 60 genera encompassing over 250 species. The Enterobacteriaceae is currently considered as the most taxonomically diverse among all seven recognized families. The emergence of carbapenem resistance (CR) in Enterobacteriaceae caused by hydrolytic enzymes called carbapenemases has become a major concern worldwide. Carbapenem-resistant Enterobacteriaceae (CRE) isolates have been reported not only in nosocomial and community-acquired pathogens but also in food-producing animals, companion animals, and the environment. The reported carbapenemases in Enterobacteriaceae from different sources belong to the Ambler class A (blaKPC), class B (blaIMP, blaVIM, blaNDM), and class D (blaOXA-48) ß-lactamases. The carbapenem encoding genes are often located on plasmids or associated with various mobile genetic elements (MGEs) like transposons and integrons, which contribute significantly to their spread. These genes are most of the time associated with other antimicrobial resistance genes such as other ß-lactamases, as well as aminoglycosides and fluoroquinolones resistance genes leading to multidrug resistance phenotypes. Control strategies to prevent infections due to CRE and their dissemination in human, animal and food have become necessary. Several factors involved in the emergence of CRE have been described. This review mainly focuses on the molecular epidemiology of carbapenemases in members of Enterobacteriaceae family from humans, animals, food and the environment.