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182100.9894Emergence and dissemination of bla(KPC-31) and bla(PAC-2) among different species of Enterobacterales in Colombia: a new challenge for the microbiological laboratories. Ceftazidime/avibactam (CZA) is a promising treatment option for infections caused by carbapenem-resistant Enterobacterales (CRE). However, CZA resistance is increasingly reported worldwide, largely due to the emergence of KPC variants and increase of metallo-β-lactamases (MBL). This study describes the mechanisms associated with CZA resistance in circulating Enterobacterales isolates from Colombia, highlighting the challenge this represents for microbiological identification. Between 2021 and 2024, 68 CZA-resistant Enterobacterales isolates were identified by automated methods in seven Colombian cities. Resistance to CZA was subsequently confirmed by broth microdilution and E-test. Carbapenemase production was evaluated using phenotypic tests, such as the mCIM test, Carba NP, lateral flow assay, and qPCR (bla(KPC), bla(NDM), bla(VIM), bla(IMP), and bla(OXA-48)). Whole-genome sequencing was performed on 15 isolates that tested negative for MBL genes. Whole-genome sequencing of these 15 isolates revealed a variety of resistance determinants: six isolates harbored bla(KPC-31), one bla(KPC-33), one bla(KPC-8), five harbored bla(PAC-2), and two co-harbored bla(PAC-2) and bla(KPC-2). Notably, bla(PAC-2) was located on an IncQ plasmid. However, some of these variants were not detected by phenotypic assays, likely due to their low or undetectable carbapenemase activity. CZA resistance in non-MBL producing Enterobacterales in Colombia is primarily mediated by the presence of bla(KPC-31) and emergence of bla(PAC-2). These resistance mechanisms pose significant diagnostic, therapeutic, and epidemiological challenges, as they frequently go undetected by conventional microbiological methods. In this context, enhanced molecular surveillance and improved diagnostic strategies are urgently needed to enable early detection, guide antimicrobial therapy, and support infection control and stewardship efforts.IMPORTANCEAntibiotic resistance is a serious global health threat. Ceftazidime/avibactam (CZA) is a key treatment option for multidrug-resistant (MDR) Enterobacterales often used when other antibiotics fail. However, bacteria are now developing resistance to this drug as well, making infections increasingly difficult to treat. In this study, we examined CZA-resistant bacteria from multiple cities in Colombia and found uncommon resistance genes across several bacterial species. These genes are frequently missed, as they often do not test positive due to the limitations of most routinely used laboratory tests. Importantly, some of these genes can be transferred between bacteria, increasing the likelihood of indiscriminate dissemination in the hospital setting. Therefore, our findings highlight the urgent need for improved diagnostic tools and molecular surveillance. Early detection will help physicians select effective treatments quickly and prevent the wider dissemination of these MDR-resistant bacteria.202541070989
249610.9890Treatment of Bloodstream Infections Due to Gram-Negative Bacteria with Difficult-to-Treat Resistance. The rising incidence of bloodstream infections (BSI) due to Gram-negative bacteria (GNB) with difficult-to-treat resistance (DTR) has been recognized as a global emergency. The aim of this review is to provide a comprehensive assessment of the mechanisms of antibiotic resistance, epidemiology and treatment options for BSI caused by GNB with DTR, namely extended-spectrum Beta-lactamase-producing Enterobacteriales; carbapenem-resistant Enterobacteriales; DTR Pseudomonas aeruginosa; and DTR Acinetobacter baumannii.202032971809
249520.9890Transmission of Mobile Colistin Resistance (mcr-1) by Duodenoscope. BACKGROUND: Clinicians increasingly utilize polymyxins for treatment of serious infections caused by multidrug-resistant gram-negative bacteria. Emergence of plasmid-mediated, mobile colistin resistance genes creates potential for rapid spread of polymyxin resistance. We investigated the possible transmission of Klebsiella pneumoniae carrying mcr-1 via duodenoscope and report the first documented healthcare transmission of mcr-1-harboring bacteria in the United States. METHODS: A field investigation, including screening targeted high-risk groups, evaluation of the duodenoscope, and genome sequencing of isolated organisms, was conducted. The study site included a tertiary care academic health center in Boston, Massachusetts, and extended to community locations in New England. RESULTS: Two patients had highly related mcr-1-positive K. pneumoniae isolated from clinical cultures; a duodenoscope was the only identified epidemiological link. Screening tests for mcr-1 in 20 healthcare contacts and 2 household contacts were negative. Klebsiella pneumoniae and Escherichia coli were recovered from the duodenoscope; neither carried mcr-1. Evaluation of the duodenoscope identified intrusion of biomaterial under the sealed distal cap; devices were recalled to repair this defect. CONCLUSIONS: We identified transmission of mcr-1 in a United States acute care hospital that likely occurred via duodenoscope despite no identifiable breaches in reprocessing or infection control practices. Duodenoscope design flaws leading to transmission of multidrug-resistant organsisms persist despite recent initiatives to improve device safety. Reliable detection of colistin resistance is currently challenging for clinical laboratories, particularly given the absence of a US Food and Drug Administration-cleared test; improved clinical laboratory capacity for colistin susceptibility testing is needed to prevent the spread of mcr-carrying bacteria in healthcare settings.201930204838
250030.9890The crisis of carbapenemase-mediated carbapenem resistance across the human-animal-environmental interface in India. Carbapenems are the decision-making antimicrobials used to combat severe Gram-negative bacterial infections in humans. Carbapenem resistance poses a potential public health emergency, especially in developing countries such as India, accounting for high morbidity, mortality, and healthcare cost. Emergence and transmission of plasmid-mediated "big five" carbapenemase genes including KPC, NDM, IMP, VIM and OXA-48-type among Gram-negative bacteria is spiralling the issue. Carbapenemase-producing carbapenem-resistant organisms (CP-CRO) cause multi- or pan-drug resistance by co-harboring several antibiotic resistance determinants. In addition of human origin, animals and even environmental sites are also the reservoir of CROs. Spillage in food-chains compromises food safety and security and increases the chance of cross-border transmission of these superbugs. Metallo-β-lactamases, mainly NDM-1 producing CROs, are commonly shared between human, animal and environmental interfaces worldwide, including in India. Antimicrobial resistance (AMR) surveillance using the One Health approach has been implemented in Europe, the United-Kingdom and the United-States to mitigate the crisis. This concept is still not implemented in most developing countries, including India, where the burden of antibiotic-resistant bacteria is high. Lack of AMR surveillance in animal and environmental sectors underestimates the cumulative burden of carbapenem resistance resulting in the silent spread of these superbugs. In-depth indiscriminate AMR surveillance focusing on carbapenem resistance is urgently required to develop and deploy effective national policies for preserving the efficacy of carbapenems as last-resort antibiotics in India. Tracking and mapping of international high-risk clones are pivotal for containing the global spread of CP-CRO.202336241158
210840.9889Prevalence and Molecular Characterization of Carbapenemase-Producing Multidrug-Resistant Bacteria in Diabetic Foot Ulcer Infections. Background: Diabetic foot ulcers (DFUs) represent severe complications in diabetic patients, often leading to chronic infections and potentially resulting in nontraumatic lower-limb amputations. The increasing incidence of multidrug-resistant (MDR) bacteria in DFUs complicates treatment strategies and worsens patient prognosis. Among these pathogens, carbapenemase-producing pathogens have emerged as particularly concerning owing to their resistance to β-lactam antibiotics, including carbapenems. Methods: This study evaluated the prevalence of MDR bacteria, specifically carbapenemase-producing pathogens, in DFU infections. A total of 200 clinical isolates from DFU patients were analyzed via phenotypic assays, including the modified Hodge test (MHT) and the Carba NP test, alongside molecular techniques to detect carbapenemase-encoding genes (blaKPC, blaNDM, blaVIM, blaIMP, and blaOXA-48). Results: Among the isolates, 51.7% were confirmed to be carbapenemase producers. The key identified pathogens included Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. The most commonly detected carbapenemase genes were blaKPC (27.6%) and blaNDM (24.1%). Carbapenemase-producing isolates presented high resistance to β-lactam antibiotics, whereas non-carbapenemase-producing isolates presented resistance through mechanisms such as porin loss and efflux pumps. Conclusions: The findings of this study highlight the significant burden of MDR infections, particularly carbapenemase-producing organisms, in DFUs. MDR infections were strongly associated with critical clinical parameters, including pyrexia (p = 0.017), recent antibiotic use (p = 0.003), and the severity of infections. Notably, the need for minor amputations was much higher in MDR cases (p < 0.001), as was the need for major amputations (p < 0.001). MDR infections were also strongly associated with polymicrobial infections (p < 0.001). Furthermore, Wagner ulcer grade ≥II was more common in MDR cases (p = 0.002). These results emphasize the urgent need for enhanced microbiological surveillance and the development of tailored antimicrobial strategies to combat MDR pathogens effectively. Given the high prevalence of carbapenem resistance, there is an immediate need to explore novel therapeutic options to improve clinical outcomes for diabetic patients with DFUs.202539857026
142550.9888Distribution and Antimicrobial Resistance of Complicated Intraabdominal Infection Pathogens in Two Tertiary Hospitals in Egypt. Background: Management of complicated intraabdominal infections (cIAIs) requires containment of the source and appropriate initial antimicrobial therapy. Identifying the local data is important to guide the empirical selection of antimicrobial therapy. In this study, we aimed to describe the pathogen distribution and antimicrobial resistance of cIAI. Methods: In two major tertiary care hospitals in Egypt, we enrolled patients who met the case definition of cIAI from October 2022 to September 2023. Blood cultures were performed using the BACTAlert system (BioMerieux, Marcy l'Etoile, France). A culture of aspirated fluid, resected material, or debridement of the infection site was performed. Identification of pathogens and antimicrobial susceptibility testing were conducted by the VITEK-2 system (BioMerieux, Marcy l'Etoile, France). Gram-negative resistance genes were identified by PCR and confirmed by whole bacterial genome sequencing using the Nextera XT DNA Library Preparation Kit and sequencing with the MiSeq Reagent Kit 600 v3 (Illumina, USA) on the Illumina MiSeq. Results: We enrolled 423 patients, 275 (65.01%) males. The median age was 61.35 (range 25-72 years). We studied 452 recovered bacterial isolates. Gram-negative bacteria were the vast majority, dominated by E. coli, followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Proteus mirabilis (33.6%, 30.5%, 13.7%, 13%, and 5.4%, respectively). High rates of resistance were detected to third- and fourth-generation cephalosporins and fluoroquinolones. No resistance was detected to colistin. Resistance to amikacin and tigecycline was low among all isolates. Resistance to meropenem and ceftazidime/avibactam was moderate. ESBL genes were common in E. coli and K. pneumoniae. CTX-M15 gene was the most frequent. Among Enterobacterales, bla(OXA-48) and bla(NDM) were the most prevalent carbapenemase genes. Pseudomonas aeruginosa isolates harbored a wide variety of carbapenemase genes (OXA, NDM, VIM, SIM, GIM, SPM, IMP, AIM), dominated by metallo-beta-lactamases. In 20.6% of isolates, we identified two or more resistance genes. Conclusion: High resistance rates were detected to third- and fourth-generation cephalosporins and fluoroquinolones. Amikacin and tigecyclines were the most active antimicrobials. Our data call for urgent implementation of antimicrobial stewardship programs and reinforcement of infection control.202439172656
210560.9888Infections Caused by Antimicrobial Drug-Resistant Saprophytic Gram-Negative Bacteria in the Environment. BACKGROUND: Drug-resistance genes found in human bacterial pathogens are increasingly recognized in saprophytic Gram-negative bacteria (GNB) from environmental sources. The clinical implication of such environmental GNBs is unknown. OBJECTIVES: We conducted a systematic review to determine how often such saprophytic GNBs cause human infections. METHODS: We queried PubMed for articles published in English, Spanish, and French between January 2006 and July 2014 for 20 common environmental saprophytic GNB species, using search terms "infections," "human infections," "hospital infection." We analyzed 251 of 1,275 non-duplicate publications that satisfied our selection criteria. Saprophytes implicated in blood stream infection (BSI), urinary tract infection (UTI), skin and soft tissue infection (SSTI), post-surgical infection (PSI), osteomyelitis (Osteo), and pneumonia (PNA) were quantitatively assessed. RESULTS: Thirteen of the 20 queried GNB saprophytic species were implicated in 674 distinct infection episodes from 45 countries. The most common species included Enterobacter aerogenes, Pantoea agglomerans, and Pseudomonas putida. Of these infections, 443 (66%) had BSI, 48 (7%) had SSTI, 36 (5%) had UTI, 28 (4%) had PSI, 21 (3%) had PNA, 16 (3%) had Osteo, and 82 (12%) had other infections. Nearly all infections occurred in subjects with comorbidities. Resistant strains harbored extended-spectrum beta-lactamase (ESBL), carbapenemase, and metallo-β-lactamase genes recognized in human pathogens. CONCLUSION: These observations show that saprophytic GNB organisms that harbor recognized drug-resistance genes cause a wide spectrum of infections, especially as opportunistic pathogens. Such GNB saprophytes may become increasingly more common in healthcare settings, as has already been observed with other environmental GNBs such as Acinetobacter baumannii and Pseudomonas aeruginosa.201729164118
140770.9887World Health Organization priority antimicrobial resistance in Enterobacterales, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecium healthcare-associated bloodstream infections in Brazil (ASCENSION): a prospective, multicentre, observational study. BACKGROUND: Carbapenem-resistant Enterobacterales (CRE), Acinetobacter baumannii (CRAB), Pseudomonas aeruginosa (CRPA), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) are listed by World Health Organization (WHO) as priority antimicrobial-resistant bacteria. Data on WHO Priority Antimicrobial resistance Phenotype (WPAP) bacteria from low- and middle-income countries are scarce. In this study, we investigated the occurrence of WPAP in healthcare-associated bloodstream infections (BSI) in Brazil, an upper-middle-income country in South America. METHODS: ASCENSION was a prospective, multicentre, observational study conducted in 14 hospitals from four of five Brazilian regions. Enterobacterales, A. baumannii, P. aeruginosa, S. aureus and E. faecium BSIs in hospitalised patients were analysed. The primary outcome was the frequency of WPAP among all bacteria of interest. Secondary outcomes were incidence-density of bacteria isolates in hospitalised patients, WPAP proportions within bacterial species, and 28-day mortality. PCR for carbapenemase genes was performed in carbapenem-resistant Gram-negative bacteria. FINDINGS: Between August 15, 2022, and August 14, 2023, 1350 isolates (1220 BSI episodes) were included. WPAP accounted for 38.8% (n = 524; 95% Confidence Interval 32.0-46.1) of all isolates, with CRE (19.3%) as the most frequent, followed by CRAB (9.6%), MRSA (4.9%), VRE (2.7%), and CRPA (2.4%). Incidence-density of all and WPAP isolates were 1.91 and 0.77/1000 patients-day, respectively. Carbapenem-resistant Klebsiella pneumoniae (CRKP) was the most common CRE, corresponding to 14.2% of all BSIs. A. baumannii isolates presented the highest proportion of WPAP (87.8%). Mortality rates were higher in patients with BSIs by WPAP than non-WPAP isolates. KPC (64.4%) was the predominant carbapenemase in CRE, followed by NDM (28.4%) and KPC + NDM co-production (7.1%). OXA-23 was the most frequent in CRAB. INTERPRETATION: A high frequency of WPAP bacteria, particularly CRKP and CRAB, were found in healthcare-associated BSIs in Brazil, posing them as a major public health problem in this country. FUNDING: National Council for Scientific and Technological Development, Brazil.202539957800
219680.9886Antibiotic resistance profiles in Gram-negative bacteria causing bloodstream and urinary tract infections in paediatric and adult patients in Ndola District, Zambia, 2020-2021. BACKGROUND: Bloodstream infections (BSIs) and urinary tract infections (UTIs) caused by antibiotic resistant bacteria (ARB) have unfavourable treatment outcomes and negative economic impacts. OBJECTIVES: The main objective of this study was to determine antibiotic resistance profiles in Gram-negative bacteria (GNB) causing BSIs and UTIs. METHOD: A prospective study from October 2020 to January 2021 at Ndola Teaching Hospital and Arthur Davison Children's Hospital in the Ndola district, Zambia. Blood and urine samples collected from inpatients and outpatients presenting with fever and/or urinary tract infection symptoms were submitted for microbiological analysis. Pathogen identification and antibiotic susceptibility was determined by the automated VITEK 2 Compact machine. Resistance genes to commonly used antibiotics were determined using polymerase chain reaction. Data were analysed using SPSS version 28.0. RESULTS: One hundred and ten GNB were isolated, E. coli (45.5%) was predominant, with varying resistance profiles to different antibiotic classes. Resistance to third-generation cephalosporin was highest in Enterobacter cloacae (75%) and Klebsiella pneumoniae (71%), respectively. Emergence of carbapenem resistance was noted with the highest being 17% in Acinetobacter baumannii. Notably, the prevalence of multi-drug resistance was 63% and extensively drug-resistance was 32%. Resistance gene determinants identified included bla (CTX-M,) qnrA and bla (NDM). CONCLUSION: High level antibiotic resistance was observed in GNB known to be prevalent causative agents of BSIs and UTIs locally in Zambia. Improving microbiology diagnostic capacity, strengthening antimicrobial stewardship programs and enforcing infection prevention and control measures are of utmost importance in promoting rational use of antibiotics and preventing the spread and emergence of resistant pathogens.202540585877
225990.9886Gram-Negative Bacteria Harboring Multiple Carbapenemase Genes, United States, 2012-2019. Reports of organisms harboring multiple carbapenemase genes have increased since 2010. During October 2012-April 2019, the Centers for Disease Control and Prevention documented 151 of these isolates from 100 patients in the United States. Possible risk factors included recent history of international travel, international inpatient healthcare, and solid organ or bone marrow transplantation.202134424168
2516100.9886Carbapenem-resistant Gram-negative bacteria (CR-GNB) in ICUs: resistance genes, therapeutics, and prevention - a comprehensive review. Intensive care units (ICUs) are specialized environments dedicated to the management of critically ill patients, who are particularly susceptible to drug-resistant bacteria. Among these, carbapenem-resistant Gram-negative bacteria (CR-GNB) pose a significant threat endangering the lives of ICU patients. Carbapenemase production is a key resistance mechanism in CR-GNB, with the transfer of resistance genes contributing to the extensive emergence of antimicrobial resistance (AMR). CR-GNB infections are widespread in ICUs, highlighting an urgent need for prevention and control measures to reduce mortality rates associated with CR-GNB transmission or infection. This review provides an overview of key aspects surrounding CR-GNB within ICUs. We examine the mechanisms of bacterial drug resistance, the resistance genes that frequently occur with CR-GNB infections in ICU, and the therapeutic options against carbapenemase genotypes. Additionally, we highlight crucial preventive measures to impede the transmission and spread of CR-GNB within ICUs, along with reviewing the advances made in the field of clinical predictive modeling research, which hold excellent potential for practical application.202438601497
2115110.9885Assessment of carbapenemase genes and antibiotic resistance profiles in ceftazidime-avibactam resistant Klebsiella pneumoniae isolates: A single-center cross-sectional study. BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is an urgent global health threat due to its rapid spread and limited treatment options. Ceftazidime-avibactam exhibits broad efficacy against gram-negative bacteria, including CRKp; however, emerging resistance to this agent is increasingly reported. Understanding the prevalence of ceftazidime-avibactam resistance and the underlying carbapenemase genes is critical for optimizing antimicrobial stewardship and guiding clinical management. This study aimed to determine the prevalence of ceftazidime avibactam resistance among CRKp isolates collected from various clinical specimens, and to analyze their associated carbapenemase genes and antibiotic resistance profiles. METHODS: This cross-sectional study analyzed 312 K pneumoniae isolates obtained from various clinical specimens of hospitalized patients at a tertiary care hospital in Turkey. Antibiotic susceptibility testing was performed using the disk diffusion method for ceftazidime-avibactam and broth microdilution for both colistin and ceftazidime-avibactam. Molecular detection of carbapenemase genes was carried out using polymerase chain reaction. RESULTS: Ceftazidime-avibactam resistance was identified in 21.5% (67/312) of CRKp isolates. Among these isolates, 37.3% harbored both OXA-48 and NDM genes, 13.4% carried NDM alone, 10.4% carried OXA-48 alone, and 38.8% lacked these genes. The majority of resistant isolates originated from urine (31.3%), followed by tracheal aspirate (29.9%), and blood (22.4%) specimens. The prevalence of colistin susceptibility among ceftazidime-avibactam-resistant CRKp isolates was 56.7%. CONCLUSIONS: The coexistence of NDM and OXA-48 genes is a major contributor to ceftazidime-avibactam resistance in CRKp isolates, particularly in urinary and respiratory tract infections. These findings underscore the need for ongoing surveillance and tailored antibiotic stewardship programs to control the spread of resistance in hospital settings.202541088587
2267120.9884MOLECULAR CHARACTERIZATION AND DETECTION OF MULTIDRUGRESISTANT GENE IN BACTERIAL ISOLATES CAUSING LOWER RESPIRATORY TRACT INFECTIONS (LRTI) AMONG HIV/AIDS PATIENTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) IN UYO, SOUTH-SOUTH NIGERIA. BACKGROUND: Antibiotic-resistant genes (ARGs) pose a significant challenge in modern medicine, rendering infections increasingly difficult to treat as bacteria acquire mechanisms to resist antibiotics. Addressing ARGs necessitates a multifaceted approach, encompassing surveillance efforts to monitor their presence and the development of strategies aimed at managing and curbing the spread of antibiotic resistance. Hence, this study characterized the genetic determinants of antibiotic resistance among isolates responsible for Lower Respiratory Tract Infections (LRTIs) in People Living with HIV/AIDS (PLWHA) in Uyo. METHODS: Sputum samples were collected from 61 LRTI suspects, with bacterial isolates identified using VITEK-2 technology. Polymerase chain reaction assays were employed to detect resistance genes within the isolates. RESULTS: Results revealed a bacterial etiology in 39.3% of the samples, with a majority (79.2%) originating from St. Luke Hospital, Anua (SLHA), and the remainder (20.8%) from the University of Uyo Teaching Hospital (UUTH). Staphylococcus aureus emerged as the predominant isolate (46.6%), while resistance was notably high against Gentamicin and Sulphamethazole/Trimethoprim. Conversely, Azithromycin, imipenem, clindamycin, erythromycin, and ceftriaxone displayed relatively lower resistance levels across all isolates. Notably, four resistance genes CTX-M, Aac, KPC, and MecA were identified, with CTX-M detected in all multidrug-resistant isolates. This underscores the predominantly community-acquired nature of resistance as conferred by CTX-M. CONCLUSION: In conclusion, this study underscores the critical importance of continued vigilance and proactive measures in combating antibiotic resistance, particularly within vulnerable populations such as PLWHA. By elucidating the genetic mechanisms underlying antibiotic resistance, informed targeted interventions can be mitigated to curb threats posed by multidrug-resistant bacteria in clinical settings.202440385712
2256130.9883Bacterial Resistance in Hospital-Acquired Infections Acquired in the Intensive Care Unit: A Systematic Review. PURPOSE: In this review we present the status of the prevalence of bacteria resistant to antibiotics and the main antibiotic resistance genes that are reported in infections acquired in intensive care units (ICU) around the world. METHODS: A systematic review based on the PRISMA guide was carried out, from the Science Direct, Redalyc, Scopus, Hinari, Scielo, Dialnet, PLOS, ProQuest, Taylor, Lilacs and PubMed/Medline databases. Inclusion criteria of this review were original research study published in a scientific journal in a 10-year time span from 1 January 2017 and 30 April 2022. RESULTS: A total of 1686 studies were identified, but only 114 studies were considered eligible for inclusion. Klebsiella pneumoniae and Escherichia coli resistant to carbapenems and producers of extended-spectrum β-lactamases (ESBL) are the most frequently isolated pathogens in ICUs in Asia, Africa and Latin America. The blaOXA and blaCTX were antibiotic resistance genes (ARG) most commonly reported in different geographic regions (in 30 and 28 studies, respectively). Moreover, multidrug-resistant (MDR) strains were reported in higher frequency in hospital-acquired infections. Reports of MDR strains vary between continents, with the majority of publications being in Asia and between countries, with Egypt and Iran being highlighted. There is a predominance of few bacterial clones with MDR phenotype, for example, clonal complex 5 Methicillin-Resistant Staphylococcus aureus (CC5-MRSA) circulates frequently in hospitals in the United States, clone ST23-K. pneumoniae is reported in India and Iran, and clone ST260 carbapenemase-producing P. aeruginosa in the United States and Estonia. CONCLUSION: Our systematic review reveals that ESBL- and carbapenemase-producing K. pneumoniae and E. coli are the most problematic bacteria that are reported, mainly in tertiary hospitals in Asia, Africa, and Latin America. We have also found propagation of dominant clones with a high degree of MDR, becoming a problem due to its high capacity to cause morbidity, mortality and additional hospital costs.202337384803
840140.9883Outbreak of colistin and carbapenem-resistant Klebsiella pneumoniae ST16 co-producing NDM-1 and OXA-48 isolates in an Iranian hospital. BACKGROUND: Colistin and carbapenem-resistant Klebsiella pneumoniae (Col-CRKP) represent a significant and constantly growing threat to global public health. We report here an outbreak of Col-CRKP infections during the fifth wave of COVID-19 pandemic. METHODS: The outbreak occurred in an intensive care unit with 22 beds at a teaching university hospital, Isfahan, Iran. We collected eight Col-CRKP strains from seven patients and characterized these strains for their antimicrobial susceptibility, determination of hypermucoviscous phenotype, capsular serotyping, molecular detection of virulence and resistance genes. Clonal relatedness of the isolates was performed using MLST. RESULTS: The COVID-19 patients were aged 24-75 years with at least 50% pulmonary involvement and were admitted to the intensive care unit. They all had superinfection caused by Col-CRKP, and poor responses to antibiotic treatment and died. With the exception of one isolate that belonged to the ST11, all seven representative Col-CRKP strains belonged to the ST16. Of these eight isolates, one ST16 isolate carried the iucA and ybtS genes was identified as serotype K20 hypervirulent Col-CRKP. The bla(SHV) and bla(NDM-1) genes were the most prevalent resistance genes, followed by bla(OXA-48) and bla(CTX-M-15) and bla(TEM) genes. Mobilized colistin-resistance genes were not detected in the isolates. CONCLUSIONS: The continual emergence of ST16 Col-CRKP strains is a major threat to public health worldwide due to multidrug-resistant and highly transmissible characteristics. It seems that the potential dissemination of these clones highlights the importance of appropriate monitoring and strict infection control measures to prevent the spread of resistant bacteria in hospitals.202438368365
841150.9882blaOXA-48 carrying clonal colistin resistant-carbapenem resistant Klebsiella pneumoniae in neonate intensive care unit, India. Bacteria resistant to colistin, a last resort antibiotic reflect the pre-antibiotic era. In this study, colistin resistance carbapenem-resistant K. pneumoniae (COL(R)- CRKP) strains from neonate's intensive care unit were evaluated. Molecular analysis showed that all the four colistin resistant K. pneumoniae isolates were clonally related with strong biofilm formation ability and harbored bla(SHV-34) and bla(OXA-48) genes. Our result suggested the need of proper surveillance and adequate infection control to limiting the spread of these organisms.201627622347
1538160.9882KPC-2 allelic variants in Klebsiella pneumoniae isolates resistant to ceftazidime-avibactam from Argentina: bla(KPC-80), bla(KPC-81), bla(KPC-96) and bla(KPC-97). Ceftazidime-avibactam (CZA) therapy has significantly improved survival rates for patients infected by carbapenem-resistant bacteria, including KPC producers. However, resistance to CZA is a growing concern, attributed to multiple mechanisms. In this study, we characterized four clinical CZA-resistant Klebsiella pneumoniae isolates obtained between July 2019 and December 2020. These isolates expressed novel allelic variants of bla(KPC-2) resulting from changes in hotspots of the mature protein, particularly in loops surrounding the active site of KPC. Notably, KPC-80 had an K269_D270insPNK mutation near the Lys270-loop, KPC-81 had a del_I173 mutation within the Ω-loop, KPC-96 showed a Y241N substitution within the Val240-loop and KPC-97 had an V277_I278insNSEAV mutation within the Lys270-loop. Three of the four isolates exhibited low-level resistance to imipenem (4 µg/mL), while all remained susceptible to meropenem. Avibactam and relebactam effectively restored carbapenem susceptibility in resistant isolates. Cloning mutant bla(KPC) genes into pMBLe increased imipenem MICs in recipient Escherichia coli TOP10 for bla(KPC-80), bla(KPC-96), and bla(KPC-97) by two dilutions; again, these MICs were restored by avibactam and relebactam. Frameshift mutations disrupted ompK35 in three isolates. Additional resistance genes, including bla(TEM-1), bla(OXA-18) and bla(OXA-1), were also identified. Interestingly, three isolates belonged to clonal complex 11 (ST258 and ST11) and one to ST629. This study highlights the emergence of CZA resistance including unique allelic variants of bla(KPC-2) and impermeability. Comprehensive epidemiological surveillance and in-depth molecular studies are imperative for understanding and monitoring these complex resistance mechanisms, crucial for effective antimicrobial treatment strategies. IMPORTANCE: The emergence of ceftazidime-avibactam (CZA) resistance poses a significant threat to the efficacy of this life-saving therapy against carbapenem-resistant bacteria, particularly Klebsiella pneumoniae-producing KPC enzymes. This study investigates four clinical isolates exhibiting resistance to CZA, revealing novel allelic variants of the key resistance gene, bla(KPC-2). The mutations identified in hotspots surrounding the active site of KPC, such as K269_D270insPNK, del_I173, Y241N and V277_I278insNSEAV, prove the adaptability of these pathogens. Intriguingly, low-level resistance to imipenem and disruptions in porin genes were observed, emphasizing the complexity of the resistance mechanisms. Interestingly, three of four isolates belonged to clonal complex 11. This research not only sheds light on the clinical significance of CZA resistance but also shows the urgency for comprehensive surveillance and molecular studies to inform effective antimicrobial treatment strategies in the face of evolving bacterial resistance.202438319084
1674170.9882Bloodstream infections caused by multidrug-resistant gram-negative bacteria: epidemiological, clinical and microbiological features. BACKGROUND: Bloodstream infections (BSI) are associated with high morbidity and mortality. This scenario worsens with the emergence of drug-resistant pathogens, resulting in infections which are difficult to treat or even untreatable with conventional antimicrobials. The aim of this study is to describe the epidemiological aspects of BSI caused by multiresistant gram-negative bacilli (MDR-GNB). METHODS: We conducted a laboratory-based surveillance for gram-negative bacteremia over a 1-year period. The bacterial isolates were identified by MALDI-TOF/MS and the antimicrobial susceptibility testing was performed by VITEK®2. Resistance genes were identified through PCR assays. RESULTS: Of the 143 patients, 28.7% had infections caused by MDR-GNB. The risk factors for MDR bacteremia were male sex, age ≥ 60, previous antimicrobial use, liver disease and bacteremia caused by K. pneumoniae. K. pneumoniae was the most frequently observed causative agent and had the highest resistance level. Regarding the resistance determinants, SHV, TEM, OXA-1-like and CTX-M-gp1 were predominant enzymatic variants, whereas CTX-M-gp9, CTX-M-gp2, KPC, VIM, GES, OXA-48-like, NDM and OXA-23-like were considered emerging enzymes. CONCLUSIONS: Here we demonstrate that clinically relevant antibiotic resistance genes are prevalent in this setting. We hope our findings support the development of intervention measures by policy makers and healthcare professionals to face antibiotic resistance.201931296179
1424180.9882Source-tracking ESBL-producing bacteria at the maternity ward of Mulago hospital, Uganda. INTRODUCTION: Escherichia coli, Klebsiella pneumoniae and Enterobacter (EKE) are the leading cause of mortality and morbidity in neonates in Africa. The management of EKE infections remains challenging given the global emergence of carbapenem resistance in Gram-negative bacteria. This study aimed to investigate the source of EKE organisms for neonates in the maternity environment of a national referral hospital in Uganda, by examining the phenotypic and molecular characteristics of isolates from mothers, neonates, and maternity ward. METHODS: From August 2015 to August 2016, we conducted a cross-sectional study of pregnant women admitted for elective surgical delivery at Mulago hospital in Kampala, Uganda; we sampled (nose, armpit, groin) 137 pregnant women and their newborns (n = 137), as well as health workers (n = 67) and inanimate objects (n = 70 -beds, ventilator tubes, sinks, toilets, door-handles) in the maternity ward. Samples (swabs) were cultured for growth of EKE bacteria and isolates phenotypically/molecularly investigated for antibiotic sensitivity, as well as β-lactamase and carbapenemase activity. To infer relationships among the EKE isolates, spatial cluster analysis of phenotypic and genotypic susceptibility characteristics was done using the Ridom server. RESULTS: Gram-negative bacteria were isolated from 21 mothers (15%), 15 neonates (11%), 2 health workers (3%), and 13 inanimate objects (19%); a total of 131 Gram-negative isolates were identified of which 104 were EKE bacteria i.e., 23 (22%) E. coli, 50 (48%) K. pneumoniae, and 31 (30%) Enterobacter. Carbapenems were the most effective antibiotics as 89% (93/104) of the isolates were susceptible to meropenem; however, multidrug resistance was prevalent i.e., 61% (63/104). Furthermore, carbapenemase production and carbapenemase gene prevalence were low; 10% (10/104) and 6% (6/104), respectively. Extended spectrum β-lactamase (ESBL) production occurred in 37 (36%) isolates though 61 (59%) carried ESBL-encoding genes, mainly blaCTX-M (93%, 57/61) implying that blaCTX-M is the ideal gene for tracking ESBL-mediated resistance at Mulago. Additionally, spatial cluster analysis revealed isolates from mothers, new-borns, health workers, and environment with similar phenotypic/genotypic characteristics, suggesting transmission of multidrug-resistant EKE to new-borns. CONCLUSION: Our study shows evidence of transmission of drug resistant EKE bacteria in the maternity ward of Mulago hospital, and the dynamics in the ward are more likely to be responsible for transmission but not individual mother characteristics. The high prevalence of drug resistance genes highlights the need for more effective infection prevention/control measures and antimicrobial stewardship programs to reduce spread of drug-resistant bacteria in the hospital, and improve patient outcomes.202337289837
1678190.9881Molecular characterization and descriptive analysis of carbapenemase-producing Gram-negative rod infections in Bogota, Colombia. In this study, the genetic differences and clinical impact of the carbapenemase-encoding genes among the community and healthcare-acquired infections were assessed. This retrospective, multicenter cohort study was conducted in Colombia and included patients infected with carbapenem-resistant Gram-negative rods between 2017 and 2021. Carbapenem resistance was identified by Vitek, and carbapenemase-encoding genes were identified by whole-genome sequencing (WGS) to classify the alleles and sequence types (STs). Descriptive statistics were used to determine the association of any pathogen or gene with clinical outcomes. A total of 248 patients were included, of which only 0.8% (2/248) had community-acquired infections. Regarding the identified bacteria, the most prevalent pathogens were Pseudomonas aeruginosa and Klebsiella pneumoniae. In the WGS analysis, 228 isolates passed all the quality criteria and were analyzed. The principal carbapenemase-encoding gene was blaKPC, specifically blaKPC-2 [38.6% (88/228)] and blaKPC-3 [36.4% (83/228)]. These were frequently detected in co-concurrence with blaVIM-2 and blaNDM-1 in healthcare-acquired infections. Notably, the only identified allele among community-acquired infections was blaKPC-3 [50.0% (1/2)]. In reference to the STs, 78 were identified, of which Pseudomonas aeruginosa ST111 was mainly related to blaKPC-3. Klebsiella pneumoniae ST512, ST258, ST14, and ST1082 were exclusively associated with blaKPC-3. Finally, no particular carbapenemase-encoding gene was associated with worse clinical outcomes. The most identified genes in carbapenemase-producing Gram-negative rods were blaKPC-2 and blaKPC-3, both related to gene co-occurrence and diverse STs in the healthcare environment. Patients had several systemic complications and poor clinical outcomes that were not associated with a particular gene.IMPORTANCEAntimicrobial resistance is a pandemic and a worldwide public health problem, especially carbapenem resistance in low- and middle-income countries. Limited data regarding the molecular characteristics and clinical outcomes of patients infected with these bacteria are available. Thus, our study described the carbapenemase-encoding genes among community- and healthcare-acquired infections. Notably, the co-occurrence of carbapenemase-encoding genes was frequently identified. We also found 78 distinct sequence types, of which two were novel Pseudomonas aeruginosa, which could represent challenges in treating these infections. Our study shows that in low and middle-income countries, such as Colombia, the burden of carbapenem resistance in Gram-negative rods is a concern for public health, and regardless of the allele, these infections are associated with poor clinical outcomes. Thus, studies assessing local epidemiology, prevention strategies (including trials), and underpinning genetic mechanisms are urgently needed, especially in low and middle-income countries.202438629835