Immunomodulator AS101 restores colistin susceptibility of clinical colistin-resistant Escherichia coli and Klebsiella pneumoniae in vitro and in vivo.

Colistin (COL) was once considered to be the last line of defence against multidrug-resistant bacteria belonging to the family Enterobacteriaceae. Due to the misuse of COL, COL-resistant (COL-R) Enterobacteriaceae have emerged. To address this clinical issue and combat COL resistance, novel approaches are urgently needed. In this study, the in vitro and in vivo antimicrobial and antibiofilm effects of the immunomodulator AS101 were investigated in combination with COL against COL-R Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae). Checkerboard assay, time-kill assay, and scanning electron microscopy confirmed the in vitro antimicrobial phenotype, whereas, crystal violet staining and multidimensional confocal laser scanning microscopy with live/dead staining confirmed the antibiofilm capability of the combination therapy. Moreover, the Galleria mellonella infection model and the mouse infection model indicated the high in vivo efficacy of the combination therapy. Additionally, cytotoxicity experiments performed using human kidney-derived HK-2 cells and hemolysis assays performed using human erythrocytes collectively demonstrated safety at effective combination concentrations. Furthermore, quantification of the expression of inflammatory cytokines via ELISA confirmed the anti-inflammatory advantage of combination therapy. At the mechanistic level, changes in outer and inner membrane permeability and accumulation of ROS levels, which might be potential mechanisms for synergistic antimicrobial effects. In conclusion, this study found that AS101 can restore COL susceptibility in clinical COL-R E. coli and K. pneumoniae and also has synergistic antibiofilm and anti-inflammatory capabilities. This study provided a novel strategy to combat clinical infections caused by COL-R E. coli and K. pneumoniae.

Challenges and Trends in Gram-Negative Bacterial Infections in Critically Neonates: A Seven-and-a-Half-Year Observational Study.

OBJECTIVE: Analyze the incidence, risk factors, and fatality rates of bloodstream infections by Gram-negative bacteria (GNB-BSIs) in a Neonatal Intensive Care Unit (NICU). METHODS: This study employs a retrospective cohort design utilizing records of neonates admitted to the NICU between January 2015 and June 2022. RESULTS: Among 1,495 neonates, 5.2% developed GNB-BSIs. The average incidence of infection/1,000 patient-days was 2.9. Primary risk factors for infection included preceeding carbapenem use were significant risk factors (OR=514.4; P<0.01) and 4th generation cephalosporins (OR=66; P<0.01). Among the 85 GNB, 75.3% were fermenters, and 24.7% were non-fermenters. Of the isolates, 14.1% produced extended-spectrum beta-lactamase, and 2.3% carbapenem resistant. Infection correlated with prolonged hospital stays (10 to 39 days) and increased mortality (10% to 29.9%). CONCLUSION: The high incidence of GNB-BSIs was exacerbated by the preceeding use of broad-spectrum antimicrobials, increasing the presence of multidrug-resistant isolates and fatality rates. These findings emphasize the importance of active surveillance.

Evaluating impacts of radiation-induced sterilization on the performance and gut microbiome of mass-reared Mediterranean fruit fly (Ceratitis capitata) in Hawai'i.

Sterile insect technique (SIT) is a useful strategy for preventing and mitigative establishment of invasive insect species. SIT of the pest tephritid Mediterranean fruit fly, Ceratitis capitata (Wiedemann, 1824)WiedemannWiedemann, has been effective in preventing population establishment in vulnerable agricultural areas of the United States. However, irradiation-induced sterilization can have detrimental impacts resulting in reduced performance metrics. Mediterranean fruit fly males reared for SIT have been shown to have differences in their microbiomes relative to other population sources, which has been postulated to be a factor in how well flies compete with wild conspecifics. To identify baseline performance metrics on the effects of irradiation on the gut microbiome of mass-reared flies in Hawai'i, a study was performed to assess performance metrics and microbiome (bacterial 16S rRNA) variation across multiple timepoints. Mediterranean fruit fly pupae were selected from mass-reared trays intended for release, and paired samples were either irradiated or remained as controls and transported to the laboratory for evaluation. Irradiated flies exhibited fewer successful fliers, more rapid mortality rates, and were less active relative to control nonirradiated flies. Contrary to initial expectations, irradiation did not exert substantial impacts on the composition or diversity of bacterial reads. Samples were primarily comprised of sequences classified as Klebsiella and there were low levels of both read and taxonomic diversity relative to other 16S surveys of medfly. Although this study does not demonstrate a strong effect of irradiation alone on the Mediterranean fruit fly microbiome, there are several explanations for this discrepancy.

Calidad higiénico-sanitaria y prácticas de manufactura de alimentos en un comedor estudiantil en México / Hygienic ­ sanitary quality and food manufacturing practices in a student cafeteria in Mexico / Qualidade higiênico-sanitária e práticas de fabricação de alimentos em uma refeitório estudantil no México

Introducción: El apego a las normas oficiales sanitarias sirve para prevenir riesgos a la salud humana. Objetivo: Evaluar la calidad higiénico-sanitaria y las buenas prácticas de manufactura de alimentos (BPMA) de un comedor estudiantil en México. Materiales y métodos: Estudio cuasiexperimental y analítico. Durante el año 2020, se realizaron pruebas bacteriológicas a muestras de alimentos, agua, superficies y manos de manipuladores de alimentos, además de también evaluar las BPMA. Conforme a las normas oficiales sanitarias vigentes en México, se recolectaron 57 muestras, se aislaron y se lograron identificar patógenos. Las BPMA se valoraron en 20 manipuladores, antes y después de una intervención educativa de 10 semanas de duración y se utilizó la prueba t con α=0,05. Resultados: Más del 50 % de las muestras resultaron con microorganismos de riesgo para la salud, como Escherichia coli, Staphylococcus aureus, Pseudomonas, Acinetobacter baumanni complex y Coliformes totales. Las evaluaciones, antes y después de la intervención educativa de BPMA, evidenciaron diferencias estadísticamente significativas en el número de aciertos (p≤0,05). Conclusiones: La calidad higiénico-sanitaria del comedor analizado representó riesgo para la salud de los estudiantes, lo cual tuvo relación con la primera evaluación de las BPMA entre los manipuladores, las cuales mejoraron después de la intervención.

Introduction: Adherence to official health standards is essential to prevent human health risks. Objective: To assess the hygienic-sanitary quality and good food manufacturing practices (GMP) in a student cafeteria in Mexico. Materials and methods: Quasi-experimental and analytical study. During 2020, bacteriological tests were carried out on samples taken from food, water, surfaces, and hands of food handlers. In addition, GMP were evaluated. Based on the current Mexican official health regulations, 57 samples were collected to isolate and identify pathogens. GMP were assessed in 20 food handlers before and after a 10-week training intervention and a test was used with α=0.05. Results: More than 50% of samples were found to have microorganisms associated with health risks, including Escherichia coli, Staphylococcus aureus, Pseudomonas, Acinetobacter baumanni complex and total Coliforms. The analyses before and after the GMP training intervention showed statistically significant differences in terms of the presence of these pathogens (p≤0.05). Conclusions: The hygienic-sanitary quality of the analyzed cafeteria turned out to be a risk for the health of students, which was related to the first assessment of GMP in food handlers. Consequently, the results improved after the intervention.

Introdução: A adesão às normas sanitárias oficiais serve para prevenir riscos à saúde humana. Objetivo: Avaliar a qualidade higiênico-sanitária e as boas práticas de fabricação de alimentos (BPMA) de um refeitorio estudantil no México. Materiais e métodos: Estudo quase-experimental e analítico. Durante 2020, foram realizados testes bacteriológicos em amostras de alimentos, água, superfícies e mãos de manipuladores de alimentos, além de avaliação de BPMA. De acordo com as normas sanitárias oficiais em vigor no México, foram coletadas e isoladas 57 amostras e identificados patógenos. Os BPMA foram avaliados em 20 manipuladores, antes e após uma intervenção educativa de 10 semanas e foi utilizado o teste t com α=0,05. Resultados: Verificou-se que mais de 50% das amostras continham microrganismos de risco à saúde, como Escherichia coli, Staphylococcus aureus, Pseudomonas, complexo Acinetobacter baumanni e Coliformes totais. As avaliações, antes e após a intervenção educativa BPMA, apresentaram diferenças estatisticamente significativas no número de acertos (p≤0,05). Conclusões: A qualidade higiênico-sanitária do refeitório analisado representou um risco para a saúde dos alunos, o que esteve relacionado à primeira avaliação do BPMA entre os manipuladores, que melhorou após a intervenção.

Temporal evolution of bacterial species and their antimicrobial resistance characteristics in wound infections of war-related injuries in Ukraine from 2014 to 2023.

BACKGROUND: This study continues surveillance of antimicrobial resistance associated with combat injuries in Ukraine. AIM: To compare species composition, antibiotic resistance profiles, and emergence of new resistance genes between 2014-2020 and 2022-2023. METHODS: Retrospective multicentre microbiological survey in Ukrainian hospitals. Antibiotic susceptibility, whole genome sequencing, and MLST typing were conducted on 154 organisms obtained from 125 casualties from 2022-2023. FINDINGS: The data reveals a predominance of gram-negative bacteria, particularly Acinetobacter baumannii (35.7%), Pseudomonas aeruginosa (14.9%), and Klebsiella pneumoniae (20.7%). High levels of carbapenem resistance was observed among A. baumannii (meropenem 72,2% [(39/54) 95% CI 58.4-83.5], imipenem 66.7% [(36/54) 95% CI 52.5-78.9]), Klebsiella (meropenem 90.6% [(29/32) 95% CI 75.0-98.0], imipenem 81.2% [(26/32) 95% CI 63.6-92.8]), and P. aeruginosa (meropenem 47.8% [(11/23) 95% CI 26.8-69.4], imipenem 60.8% [(14/23) 95% CI 38.5-80.3]) strains. A. baumannii ST-78 and ST-400 were prevalent from 2014 to 2020, while 5 strains of ST-1077 were newly identified. Pseudomonas aeruginosa strains showed diversity across 16 sequence types (STs), with ST-773 increasing in frequency and new STs emerging, but lacking carbapenemase genes. K. pneumoniae exhibited increased genetic diversity over time, with three STs from 2014 to 2020 and six new STs, including blaNDM-1, blaOXA-48, and blaKPC2 carriers, in recent years. CONCLUSION: There is a growing prevalence of multidrug resistant isolates from globally distributed sequence types.

Bloodstream infections due to multi-drug resistant bacteria in the emergency department: prevalence, risk factors and outcomes-a retrospective observational study.

Multidrug-resistant organisms (MDROs) are prevalent in patients admitted to the Emergency Department (ED) and increase the risk of inappropriate empirical antibiotic therapy. Risk stratification for MDRO infection is essential to early identify patients requiring empirical broad-spectrum antibiotic therapy, but it remains challenging for emergency physicians. This study aimed to evaluate prevalence, risk factors, and outcomes of patients admitted to the ED with a bloodstream infection (BSI) caused by MDROs. A retrospective observational study enrolling all consecutive adult patients admitted with a BSI to the ED of Niguarda Hospital, Italy, from January 2019 to December 2021 was performed. 757 patients were enrolled, 14.1% with septic shock. 156 (20%) patients had a BSI caused by MDRO: extended-spectrum beta-lactamase (ESBL) producing Enterobacterales were the most prevalent followed by methicillin-resistant Staphylococcus aureus (MRSA). Risk factors for BSI due to MDRO and specifically for ESBL were chronic renal failure (OR 2.2; 95%CI 1.4-3.6), nursing home residency (OR 4.4; 95%CI 1.9-10.2) and antibiotic therapy in the last 90-days (OR 2.6; 95%CI 1.7-4), whereas for MRSA were dialysis (OR 12.3; 95%CI 1.8-83), antibiotic therapy and/or hospital admission in the past 90-days (OR 3.6; 95%CI 1.2-10.6) and ureteral stent or nephrostomy (OR 7.8; 95%CI 1.5-40.9). Patients with BSI due to MDRO had a higher rate of inappropriate empirical antibiotic therapy (50%) and longer length of stay, but no higher in-hospital mortality. Among patients admitted to the ED with a BSI, MDROs are frequent and often associated with inappropriate empirical antibiotic therapy. Specific updated risk factors for MDRO may help clinicians to better identify patients requiring a broader antibiotic therapy in the ED, while awaiting microbiological results.

Regional Variation in the Interpretation of Contact Precautions for Multidrug-resistant Gram-negative bacteria: a cross-sectional survey.

BACKGROUND: Contact precautions (CP) are recommended when caring for patients with carbapenemase-producing Enterobacterales (CPE), carbapenemase-producing Pseudomonas aeruginosa (CPPA), and extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E). AIM: Our aim was to determine the interpretation of CP and associated infection prevention and control (IPC) measures in the non-ICU hospital setting for patients with CPE, CPPA or ESBL-E in 11 hospitals in the Southwest of the Netherlands. METHODS: A cross-sectional survey was developed to collect information on all implemented IPC measures, including use of personal protective equipment, IPC measures for visitors, cleaning and disinfection, precautions during outpatient care and follow-up strategies. All eleven hospitals were invited to participate between November 2020 and April 2021. FINDINGS: The survey was filled together with each hospital. All hospitals installed isolation precautions for patients with CPE and CPPA during inpatient care and day admissions, whereas ten hospitals (90.9%) applied isolation precautions for patients with ESBL-E. Gloves and gowns were always used during physical contact with the patient in isolation. Large variations were identified in IPC measures for visitors, cleaning and disinfection products used, and precautions during outpatient care. Four hospitals (36.4%) actively followed up on CPE or CPPA patients with the aim to declare them CPE- or CPPA-negative as timely as possible, and two hospitals (20.0%) actively followed up on ESBL-E patients. CONCLUSION: CP are interpreted differently between hospitals, leading to regional differences in IPC measures applied in clinical settings. Harmonizing infection-control policies between the hospitals could facilitate patient transfers and benefit collective efforts of preventing transmission of MDR-GNB.

Pangenome Analysis Reveals Novel Contact-Dependent Growth Inhibition System and Phenazine Biosynthesis Operons in Proteus mirabilis BL95 That Are Located in An Integrative and Conjugative Element.

Proteus mirabilis is a leading cause of urinary tract infections and a common commensal of the gastrointestinal tract. Our recent study (JB) showed that P. mirabilis strain BL95 employs a novel contact-dependent killing system against enteric bacteria in the mouse gut and in vitro. To uncover the genetic determinants of this system, we performed whole-genome sequencing of BL95 and compared it with 98 complete genomes of P. mirabilis. BL95 carries 56 coding sequences (CDSs) not found in other P. mirabilis. Over half of these unique genes are located on a novel integrative conjugative element (ICE) named ICEPm2, inserted in tRNA-Phe and exclusive to BL95. ICEPm2 has integration, conjugation, and DNA replication modules nearly identical to ICEPm1 (common in P. mirabilis), but ICEPm2 of BL95 carries two unique operons for P. mirabilis-a phenazine biosynthesis and a contact-dependent growth inhibition (CDI) system. ICEPm2 is absent in the P. mirabilis (AR_0156) closest to BL95 and it is present in the genomes of several Escherichia coli from mouse intestines, indicating its recent horizontal mobilization. BL95 shares over 100 genes of five different secretion systems with other P. mirabilis, mostly poorly studied, making a large pool of candidate genes for the contact-dependent growth inhibition.

Yokenella regensburgei-Past, Present and Future.

Yokenella regensburgei is a Gram-negative rod part of the Enterobacteriaceae family (order Enterobacterales) and a rare cause of human infections. Although improved diagnostic methods have led to an increase in reports of this elusive pathogen, information remains limited. In order to provide a better understanding of this bacterium, we developed the first comprehensive review of its biology, biochemical profile, antimicrobial resistance pattern, virulence factors, natural reservoir and involvement in various veterinary and human infections. Human infections with this bacterium are scarcely reported, most probably due to constraints regarding its identification and biochemical similarities to Hafnia alvei. Multiple systematic searches revealed 23 cases of human infection, with a seemingly worldwide distribution, mostly in middle-aged or elderly male patients, often associated with immunosuppression. To date, Y. regensburgei has been reported in skin and soft tissue infections, bacteremia and sepsis, osteoarticular infections and in others such as urinary tract and digestive infections. The unique ability of Y. regensburgei to degrade polystyrene presents a novel and promising avenue for addressing plastic pollution in the near future. However, large-scale applications of this bacterium will undoubtedly increase human exposure, highlighting the necessity for comprehensive research into its role in human and veterinary infections, pathogenicity and antibiotic resistance.

Ceftazidime-Avibactam Use in a Case Series of Difficult-to-Treat or Recurrent Infections in Pediatric Patients with Complex Chronic Conditions: Effectiveness and Absence of Resistance Development.

The prevalence of multidrug-resistant Gram-negative infections, particularly carbapenem-resistant strains, has become a significant global health concern. Ceftazidime-avibactam (CZA) has emerged as a promising treatment option. However, data on its efficacy and safety in children are scarce, necessitating further investigation. We conducted a descriptive case series at a tertiary hospital in Spain from February 2019 to January 2022. Pediatric patients (<16 years) treated with CZA for confirmed or suspected multidrug-resistant Gram-negative infections were included. The clinical and microbiological characteristics, treatment approaches, and outcomes were examined. Eighteen children received CZA treatment. All had complex chronic conditions, with the most frequent underlying main diseases being liver transplantation (n = 8) and biliary atresia (n = 4). The predominant type of infection for which they received CZA was intra-abdominal infection caused or suspected to be caused by OXA-48-producing Klebsiella pneumoniae. CZA was generally well tolerated. Within the first month of starting CZA therapy, two patients died, with one case directly linked to the infection's fatal outcome. Some patients needed repeated courses of therapy due to recurrent infections, yet no resistance development was noted. In summary, the use of CZA showed effectiveness and safety, while the lack of resistance development highlights CZA's potential as a primary treatment option against OXA-48-producing infections.

Antimicrobial Resistance Surveillance: Data Harmonisation and Data Selection within Secondary Data Use.

Resistance to last-resort antibiotics is a global threat to public health. Therefore, surveillance and monitoring systems for antimicrobial resistance should be established on a national and international scale. For the development of a One Health surveillance system, we collected exemplary data on carbapenem and colistin-resistant bacterial isolates from human, animal, food, and environmental sources. We pooled secondary data from routine screenings, hospital outbreak investigations, and studies on antimicrobial resistance. For a joint One Health evaluation, this study incorporates epidemiological metadata with phenotypic resistance information and molecular data on the isolate level. To harmonise the heterogeneous original information for the intended use, we developed a generic strategy. By defining and categorising variables, followed by plausibility checks, we created a catalogue for prospective data collections and applied it to our dataset, enabling us to perform preliminary descriptive statistical analyses. This study shows the complexity of data management using heterogeneous secondary data pools and gives an insight into the early stages of the development of an AMR surveillance programme using secondary data.

Time-Dependent Shifts in Intestinal Bacteriome, Klebsiella Colonization and Incidence of Antibiotic-Resistance Genes after Allogeneic Hematopoietic Stem Cell Transplantation.

Dose-intensive cytostatic therapy and antibiotic treatment in allogeneic hematopoietic stem cell transplantation (allo-HSCT) cause severe abnormalities in a composition of gut microbiota as well as the emergence of antibiotic resistance. The data on the longitudinal recovery of major bacterial phyla and the expansion of genes associated with antibiotic resistance are limited. We collected regular stool samples during the first year after allo-HSCT from 12 adult patients with oncohematological disorders after allo-HSCT and performed 16SrRNA sequencing, multiplex PCR, conventional bacteriology and CHROMagar testing. We observed a decline in Shannon microbiota diversity index as early as day 0 of allo-HSCT (p = 0.034) before any administration of antibiotics, which persisted up to 1 year after transplantation, when the Shannon index returned to pre-transplant levels (p = 0.91). The study confirmed the previously shown decline in Bacillota (Firmicutes) genera and the expansion of E. coli/Shigella, Klebsiella and Enterococci. The recovery of Firmicutes was slower than that of other phyla and occurred only a year post-transplant. A positive correlation was observed between the expansion of E. coli/Shigella genera and blaKPC, blaCTX-M-1 and blaTEM (p < 0.001), Klebsiella spp. and blaOXA-48-like, blaNDM, blaCTX-M-1, blaTEM, and blaSHV (p < 0.001), Pseudomonas spp. and blaNDM (p = 0.002), Enterococcus spp. and blaOXA-48-like, blaNDM, blaCTX-M-1, blaSHV (p < 0.01). The correlation was observed between the expansion of Enterobacterales and and carbapenemase-positive CHROMagar samples (p < 0.001). Samples positive for carbapenem-resitant bacteria were at their maximum levels on day +30, and were gradually diminishing one year after allo-HSCT. From day +30 to +60, all isolated K. pneumoniae strains in fecal samples proved to be resistant to the main antibiotic groups (carbapenems, aminoglycosides, fluoroquinolones, third-generation cephalosporins). One year after HSCT, we documented the spontaneous decolonization of K. pneumoniae. The sensitivity of molecular biology techniques in the search for total and antibiotic-resistant Klebsiella seems to be superior to common bacteriological cultures. Future studies should be focused on searching for novel approaches to the efficient reconstitution and/or maintenance of strictly anaerobic microbiota in oncological patients.

Preliminary snapshot reveals a relationship between multidrug-resistance and biofilm production among enterobacteriaceae isolated from fecal samples of farm-raised poultry in ceará, Brazil.

Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for ß-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of ß-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC ß-lactamase and extended-spectrum ß-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.

Phenotypic antibiotic susceptibility profile of clinical Enterobacteriaceae isolates from Kaduna State, northwest Nigeria.

Background. The increasing resistance of clinical Enterobacteriaceae isolates to commonly prescribed antibiotics has been reported around the world. Data are generally lacking on the prevalence and antibiotic susceptibility profile of clinical Enterobacteriaceae isolates from Kaduna, northwest Nigeria. This study thus aimed to determine the diversity and antibiotic resistance profile of clinical Enterobacteriaceae isolates recovered from clinical specimens from patients admitted to two selected healthcare institutions in Kaduna. Methods. This was a prospective cross-sectional study conducted between September and December 2021. Non-duplicate clinical bacterial isolates recovered from various specimens were collected and identified using rapid biochemical identification kits. The susceptibility of identified Enterobacteriaceae to various antibiotics and phenotypic detection of carbapenemase enzymes were thereafter determined. The data were analysed and visualized using R software version 4.3.1. Results. Of the 500 bacterial isolates recovered from specimens collected for the purpose of clinical bacteriology diagnostics, 108 (21.6 %) were identified as Enterobacteriaceae, with Pantoea agglomerans (52, 48.1 %) and Klebsiella oxytoca (19, 17.6 %) being the most prevalent. The isolates exhibited high resistance to azithromycin (69 %) and ceftazidime (42 %), while exhibiting low resistance to amikacin (7 %) and imipenem (10 %). Among the carbapenem-resistant Enterobacteriaceae (CRE) isolates, a significant proportion (12/17, 70.6 %) tested positive for carbapenemase activity. Conclusion. This study reports a high prevalence of multidrug-resistant Enterobacteriaceae in Kaduna, northwest Nigeria. The emergence of pathogenic P. agglomerans and an alarmingly high prevalence of carbapenemase-producing CRE were also observed. The presence of carbapenemase producers in an area with low carbapenem usage and resistance rates raises significant concerns. Continuous surveillance and robust antibiotic stewardship policies are imperative to preserve the efficacy of carbapenems in this region.

Carbapenem-resistant Enterobacteriaceae in the livestock, humans and environmental samples around the globe: a systematic review and meta-analysis.

Carbapenem-resistant Enterobacteriaceae (CRE) have diminished treatment options causing serious morbidities and mortalities. This systematic review and meta-analysis assessed the prevalence and associated factors of Enterobacteriaceae infections in clinical, livestock and environmental settings globally. The population intervention comparison and outcome strategy was used to enroll studies using the preferred reporting system for systematic review and meta-analysis to include only cross-sectional studies. Search engines used to retrieve articles included journal author name estimator, PubMed, Google Scholar and African Journals Online (AJOL). The Newcastle-Ottawa scale was used to assess the quality of studies. Sixteen articles from 2013 to 2023 in Africa, Asia, Europe and South America were studied. The pooled prevalence of CRE was 43.06% (95% CI 21.57-66.03). Klebsiella pneumoniae (49.40%), Escherichia coli (26.42%), and Enterobacter cloacae (14.24%) were predominant. Klebsiella pneumoniae had the highest resistance with the blaKPC-2 in addition to blaNDM, blaOXA-48, blaIMP and blaVIM. The blaKPC-2 genes occurrence was associated with environmental (P-value < 0.0001) and South American studies (P-value < 0.0001), but there was no difference in the trends over time (P-value = 0.745). This study highlights the high rates of CRE infections, particularly within blaKPC production. Monitoring and surveillance programs, research and infection control measures should be strengthened. Additionally, further studies are needed to explore the mechanisms driving the predominance of specific bacterial species and the distribution of resistance genes within this bacterial family.

Thematic description of factors linked with extended-spectrum beta-lactamase-producing Enterobacteriaceae in humans.

Background: Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are associated with serious antimicrobial-resistant infections in Canadians. Humans are exposed to ESBL-producing Enterobacteriaceae through many interconnected pathways. To better protect Canadians, it is important to generate an understanding of which sources and activities contribute most to ESBL exposure and infection pathways in Canada. Objective: The aims of this scoping review were to thematically describe factors potentially associated with ESBL-producing Enterobacteriaceae colonization, carriage and/or infection in humans from countries with a very high human development index and describe the study characteristics. Methods: Four databases (PubMed, CAB Direct, Web of Science, EBSCOhost) were searched to retrieve potentially relevant studies. Articles were screened for inclusion, and factors were identified, grouped thematically and described. Results: The review identified 381 relevant articles. Factors were grouped into 13 themes: antimicrobial use, animals, comorbidities and symptoms, community, demographics, diet and substance use, health care, household, occupation, prior ESBL colonization/carriage/infection, residential care, travel, and other. The most common themes reported were demographics, health care, antibiotic use and comorbidities and symptoms. Most articles reported factors in hospital settings (86%) and evaluated factors for ESBL-producing Enterobacteriaceae infections (52%). Conclusion: This scoping review provided valuable information about which factor themes have been well described (e.g., health care) and which have been explored less frequently (e.g., diet or animal contact). Themes identified spanned human, animal and environmental contexts and settings, supporting the need for a diversity of perspectives and a multisectoral approach to mitigating exposure to antimicrobial resistance.

Colistin resistance in ESBL- and Carbapenemase-producing Escherichia coli and Klebsiella pneumoniae clinical isolates in Cambodia.

OBJECTIVES: Despite the critical importance of colistin as a last-resort antibiotic, limited studies have investigated colistin resistance in human infections in Cambodia. This study aimed to investigate the colistin resistance and its molecular determinants among Extended-spectrum beta-lactamase (ESBL)- and carbapenemase-producing (CP) Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) isolated in Cambodia between 2016 and 2020. METHODS: E. coli (n = 223) and K. pneumoniae (n = 39) were tested for colistin minimum inhibitory concentration (MIC) by broth microdilution. Resistant isolates were subjected to polymerase chain reaction (PCR) for detection of mobile colistin resistance genes (mcr) and chromosomal mutations in the two-component system (TCS). RESULTS: Eighteen isolates (10 K. pneumoniae and 8 E. coli) revealed colistin resistance with a rate of 5.9% in E. coli and 34.8% in K. pneumoniae among ESBL isolates, and 1% in E. coli and 12.5% in K. pneumoniae among CP isolates. The resistance was associated with mcr variants (13/18 isolates, mcr-1, mcr-3, and mcr-8.2) and TCS mutations within E. coli and K. pneumoniae, with the first detection of mcr-8.2 in Cambodia, the discovery of new mutations potentially associated to colistin resistance in the TCS of E. coli (PhoP I47V, PhoQ N352K, PmrB G19R, and PmrD G85R) and the co-occurrence of mcr genes and colistin resistance conferring TCS mutations in 11 of 18 isolates. CONCLUSIONS: The findings highlight the presence of colistin resistance in ESBL- and CP- Enterobacteriaceae involved in human infections in Cambodia as well as chromosomal mutations in TCS and the emergence of mcr-8.2 in E. coli and K. pneumoniae. It underscores the need for continuous surveillance, antimicrobial stewardship, and control measures to mitigate the spread of colistin resistance.

Antibiotic Resistance in Enterococci and Enterobacteriaceae from Laboratory-Reared Fresh Mealworm Larvae (Tenebrio molitor L.) and Their Frass.

The occurrence of antibiotic-resistant bacteria in foodstuff involves a human health risk. Edible insects are a precious resource; however, their consumption raises food safety issues. In this study, the occurrence of antibiotic resistant bacteria in laboratory-reared fresh mealworm larvae (Tenebrio molitor L.) and frass was assessed. Antibiotics were not used during the rearing. Enterobacteriaceae and enterococci were isolated from 17 larvae and eight frass samples. In total, 62 and 69 isolates presumed to belong to Enterobacteriaceae and Enterococcus spp., respectively, were obtained and tested for antibiotic susceptibility via disk diffusion. Based on the results, isolates were grouped, and representative resistant isolates were identified at species level through 16S rRNA gene sequencing. For enterococci resistance, percentages higher than 15% were observed for vancomycin and quinupristin-dalfopristin, whereas Enterobacteriaceae resistance higher than 25% was found against cefoxitin, ampicillin, and amoxicillin-clavulanic acid. Based on the species identification, the observed resistances seemed to be intrinsic both for enterococci and Enterobacteriaceae, except for some ß-lactams resistance in Shigella boydii (cefoxitin and aztreonam). These could be due to transferable genetic elements. This study suggests the need for further investigations to clarify the role of edible insects in the spreading of antibiotic resistance determinants through the food chain.

Favourable effect of clavulanic acid on the minimum inhibitory concentrations of cefixime and ceftibuten in ESBL-producing Escherichia coli and Klebsiella pneumoniae.

OBJECTIVES: The use of cephalosporins combined with clavulanate for the treatment of ESBL-harbouring Enterobacteriaceae has been scarcely described. We aimed to describe the effect of different concentrations of clavulanate in the MIC of cefixime and ceftibuten of ESBL-producing Escherichia coli and Klebsiella pneumoniae. METHODS: ESBL-producing E. coli and K. pneumoniae isolates were studied. Fixed concentrations of cefixime and ceftibuten (ranges of 32-0.25 and 64-0.5 ng/ml, respectively) were used. Combinations of cefixime/clavulanate and ceftibuten/clavulanate in different ratios (1:0, 1:1, 2:1, 4:1, 8:1, 16:1, 32:1) were tested. MIC were determined by broth microdilution. RESULTS: A total of 6 ESBL-producing E. coli, 6 ESBL-producing K. pneumoniae and 2 control E. coli were tested. When different quantities of clavulanate were added to cefixime and ceftibuten, greater than two-fold decreases in the MIC were observed. When testing the 1:1 cefixime/clavulanate ratio, 10/12 isolates were susceptible. When the ratios 2:1, 4:1, 8:1 and 16:1 were tested, susceptibility was noted for 9/12, 8/12, 4/12 and 5/12 isolates, respectively. Only 2/12 K. pneumoniae isolates were susceptible when the ratio 32:1 was tested. When testing ceftibuten/clavulanate, all isolates remained susceptible across all experiments. CONCLUSIONS: Clavulanic acid has a favourable effect in reducing the MIC of cefixime and ceftibuten in isolates of ESBL-producing E. coli and K. pneumoniae. Combining clavulanate with ceftibuten or cefixime could be a useful treatment strategy.