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[Display omitted] • New study to expand the use of sugarcane bagasse (SCB) in the biorefinery concept. • Minimized cellulase at 15 U/g NaOH-pretreated SCB efficiently released sugars (70.8%). • K. oxytoca KIS004-91T produced D-lactate at 99.9 g/L with 0.97 g/g by fed-batch SSF. • D-lactate yield approached 97% theoretical maximum with 99.5% optical purity. Sugarcane bagasse (SCB) was utilized for efficiently producing optically pure D-(−)-lactate by Klebsiella oxytoca KIS004-91T strain. Cellulase (15 U/g NaOH-treated SCB) sufficiently liberated high sugars with saccharifications of 79.8 % cellulose and 52.5 % hemicellulose. For separated hydrolysis and fermentation, D-(−)-lactate was produced at 53.5 ± 2.1 g/L (0.98 ± 0.01 g/g sugar utilized or 0.71 ± 0.01 g/g total sugars) while D-(−)-lactate at 47.2 ± 1.8 g/L (0.78 ± 0.03 g/g sugar used or 0.69 ± 0.01 g/g total sugars) was obtained under simultaneous saccharification and fermentation (SSF). D-(−)-lactate at 99.9 ± 0.9 g/L (0.97 ± 0.01 g/g sugar utilized or 0.78 ± 0.01 g/g total sugars) was improved via fed-batch SSF. Based on mass balance, raw SCB of 7 kg is required to produce 1 kg D-(−)-lactate. Unlike others, D-(−)-lactate production was performed in low-cost salt medium without requirements of rich nutrients. Costs regarding medium, purification, and waste disposal may be reduced. This unlocks economic capability of SCB bioconversion or agricultural and agro-industrial wastes into high valuable D-(−)-lactate. [ABSTRACT FROM AUTHOR]

[Display omitted] • K. oxytoca KP001-TF60 (Δ adhE Δ pta-ackA Δ ldhA Δ budAB Δ pflB Δ tdcD Δ pmd) was engineered. • Levels of pck, ppc and frd transcripts were up-regulated. • Genes in sugars-specific PTS and ABC transporters were mostly mutated in strain. • Major Facilitator Superfamily seems to be functional to transport sugars instead. • The strain produced succinate at 0.89 g/g with acetate less than 1 g/L. Klebsiella oxytoca KP001-TF60 (Δ adhE Δ pta-ackA Δ ldhA Δ budAB Δ pflB Δ tdcD Δ pmd) was re-engineered to direct more carbon flux towards succinate production with less acetate. Glucose uptake, cell growth, and carbon distribution were restricted by alterations in relative expressions and nucleotide sequences of genes associated with PEP and pyruvate metabolisms. Transcripts of pck , ppc , and frd genes were up-regulated for enhancing NADH reoxidation during succinate production while increased pyk and tdcE transcripts were observed due to maintenance of acetyl-CoA through the oxidative branch of TCA cycle. Based on whole-genome sequencing, several genes in sugars-specific PTS (ptsG , bglF , chbR , fruA , mtlR , and treY), ABC transporters (alsK , and rbsK), Major Facilitator Superfamily (uhpB and setB), and catabolite repression (cyaA and csrB) were found to be mutated. The strain produced succinate yield up to 0.89 g/g (∼80 % theoretical maximum) with acetate < 1 g/L, and may be one of the succinate producers applied in an industrial-production scale with simplified purification processes. [ABSTRACT FROM AUTHOR]

Background and Aim: Over recent years, antimicrobial-resistant Klebsiella species in humans, animals, food animals, food products, and agricultural environments have been the center of attention due to its role in the evolution of antimicrobial resistance. The emergence of resistance to fluoroquinolones and cephalosporins of third and higher generations in Klebsiella oxytoca has not received much attention in animal husbandry compared to that in Klebsiella pneumoniae. Reports on K. oxytoca are limited in the study area. Therefore, we investigated the antimicrobial susceptibility and resistance genes in K. oxytoca isolated from slaughtered pigs in Thailand. Materials and Methods: Microbiological examination was conducted on 384 Klebsiella spp. isolates recovered from slaughtered pigs in ten provinces of Thailand. Seventy-two K. oxytoca isolates (18.75%) were examined for antimicrobial-resistant genes (β-lactamase [blaTEM, blaCTX-M, and blaSHV]) and fluoroquinolone-resistant genes (qnrA, qnrB, qnrC, qnrD, qnrS, oqxAB, aac(6')-Ib-cr, and qepA). Results: The most common genotype was blaCTX-M (58/72, 80.55%), followed by blaTEM with blaCTX-M (7/72, 9.72%) and blaTEM (6/72, 8.33%). The most common blaCTX-M group was blaCTX-M-1 (19/58, 32.76%), followed by blaCTX-M-9 (1/58, 1.72%). Plasmid-mediated quinolone resistance genes were identified in 13 (18.05%) isolates: qnrS (16.70%) and qnrB (1.4%). All 13 isolates had qnrS transferable to an Escherichia coli recipient, whereas qnrB was not detected in any transconjugants. Either blaCTX-M or blaTEM harbored by one K. oxytoca strain was transferable to an E. coli recipient. Analysis of antimicrobial susceptibility revealed that more than 90% of the blaCTX-M-carrying K. oxytoca isolates were susceptible to chloramphenicol, trimethoprim, ceftazidime, cefepime, cefotaxime, amoxicillin-clavulanic acid, piperacillin–tazobactam, and fosfomycin. All K. oxytoca isolates (13) harboring qnr were susceptible to carbapenem and ceftriaxone; however, 43 (74.13%) of the K. oxytoca isolates harboring blaCTX-M exhibited extended-spectrum β-lactamase activity. Most of the K. oxytoca isolates from pigs were highly resistant to ampicillin, azithromycin, and gentamicin. Conclusion: To prevent further transmission of Klebsiella spp. between food animals and humans, strict control of antibiotic use in clinical and livestock settings is necessary along with routine disinfection of the livestock environment and efforts to increase awareness of antimicrobial resistance transmission.

Spontaneous pyogenic spondylodiscitis (SPS) is an uncommon disease. The most common causative organism of SPS is Staphylococcus aureus, followed by Gram-negative bacilli in 4%–30% of the cases. Polymicrobial SPS is very rare, with only a few cases reported in the literature. We report a case of polymicrobial SPS in a 43-year-old male who was recently diagnosed with autoimmune hepatitis with cirrhosis of the liver and presented with a 1-month history of progressive low backache with radiation to both the legs. Initially, he was managed as a case of Pott's spine with antitubercular therapy on the basis of immunocompromised status with positive ascitic fluid Mycobacterium tuberculosis polymerase chain reaction. However, due to lack of clinical and radiological response after 6 weeks, he underwent computed tomography-guided biopsy of the affected region. The culture from the biopsy specimen yielded Klebsiella oxytoca and Proteus vulgaris. He was managed with culture-sensitive antimicrobials. To the best of our knowledge, this is the first case of polymicrobial SPS caused by K. oxytoca, P. vulgaris, and M. tuberculosis.

A carbapenem resistant but ceftriaxone and cefepime susceptible Klebsiella oxytoca was isolated from the blood of a patient with polymicrobial bacteremia after 2 weeks of ertapenem treatment. Whole-genome sequencing identified no carbapenemase gene nor plasmid, but only blaOXY-2-8 gene with a mutation in the promoter that's been reported to increase its expression. Two other specific carbapenem resistance mechanisms including mutated porin genes and the AcrAB-TolC efflux system genes were also identified. Clinicians need to be aware of such unusual antibiogram and should not assume carbapenems are always broader spectrum antibiotics than expanded-spectrum cephalosporins.

Background and Objectives: Carbapenems are considered the last resort to treat several infections, particularly in intensive care units (ICUs). However, increasing carbapenem resistance is problematic because it leads to high morbidity and mortality rates. This study aimed to determine the rate of carbapenem resistance among Gram-negative bacteria collected from patients in ICUs and to identify their resistance mechanisms using phenotypic and genotypic methods. Materials and Methods: Antimicrobial susceptibility testing was carried out using the disc diffusion method among 180 Gram-negative bacterial isolates. Productions of carbapenemases, metallo-beta-lactamases (MBLs) and the harboring of carbapenemase-encoding genes, were detected in 40 selected carbapenem-resistant Gram-negative bacteria (CR-GNB). Results: Of 40 selected CR-GNB isolates, 28 (70%), and 20 (50%) isolates were phenotypically positive for carbapenemase, and MBL production, respectively. Furthermore, 22 (55%) showed amplification of one or more of the carbapenemase-encoding genes, including blaNDM-1, blaVIM-2, and blaOXA-48. This study described the first emergence of NDM-1 producing Klebsiella oxytoca in Egyptian ICUs. Conclusion: High incidence of CR-GNB detected in the ICUs in our study area may be attributed to the overuse of antibiotics, including carbapenems, and improper application of infection control measures. These findings confirm the need for the application of a strict antibiotic stewardship program.

Antimicrobial resistance is a threat to public health. Fresh foods, especially ready-to-eat (RTE) products, can serve as vehicle for resistance dissemination if eaten directly without further processing by the consumer. This study investigated the presence of Enterobacterales resistant to clinically relevant antibiotics in RTE products acquired from 3 Portuguese supermarkets. Food samples (n = 42) were processed and plated in selective medium, followed by the identification of the isolates as well as the determination of the antibiotic resistance profile. Environmental bacteria resistant to beta-lactams and colistin were detected. Furthermore, the detection of Yersinia enterocolitica and Klebsiella oxytoca isolates was of special relevance. [ABSTRACT FROM AUTHOR]

Simple Summary: The increasing incidence of multidrug-resistant microbes is a major problem in human and veterinary medicine. In our study we assessed the prevalence and antibiotic resistance of Klebsiella spp. strains isolated from turkey broilers and breeders. The obtained results show that isolates have become more susceptible to most of the popular antimicrobials. One of the important problems in poultry production is bacterial infections and increasing resistance to antibiotics. The increasing incidence of multidrug-resistant bacteria is a major challenge for physicians and veterinarians and considerably limits treatment options. This study was undertaken in order to assess the prevalence and antibiotic resistance of Klebsiella spp. strains isolated from turkeys sampled from 2019 to 2022 in Poland. The material for study consisted of clinical samples taken during routine monitoring and microbiological identification testing at commercial poultry farms. From all 507 isolates of Klebsiella, 95% were identified by MALDI-TOF (Matrix-Assisted Laser Desorption - Ionisation-Time of Flight) as Klebsiella pneumonia, 2% were Klebsiella oxytoca, 2% Klebsiella variicola, or unidentified (1%). All isolated Klebsiella strains were tested for antimicrobial susceptibility by disk diffusion. The results of our study indicated that colistin, neomycin, florfenicol and amoxicillin/clavulanic acid were the most effective against the Klebsiella spp. isolated from turkeys. In addition, the results show a decrease in the number of multi-resistant Klebsiella spp. strains between 2019 and 2021. [ABSTRACT FROM AUTHOR]

Background: Long-term peritoneal dialysis (PD), especially with nonphysiological solutions, is afflicted with the severe complication of encapsulating peritoneal sclerosis (EPS). Physiologic PD solutions have been introduced to reduce pH trauma. Data on peritoneal biopsies in pediatrics with long-term PD using physiological solutions are scant. Case Report: We report an adolescent who had been on 10-h continuous hourly cycles using mostly 2.27% Physioneal™ for 5 years. There were two episodes of peritonitis in October 2017 (Klebsiella oxytoca) and May 2018 (Klebsiella pneumoniae), which were treated promptly. This adolescent, who lost two kidney transplants from recurrent focal and segmental glomerulosclerosis, underwent a peritoneal membrane biopsy at the time of a third PD catheter placement, 16 months after the second renal transplant. Laparoscopically, the peritoneum appeared grossly normal, but fibrosis and abundant hemosiderin deposition were noted on histology. The thickness of the peritoneum was 200–900 (mean 680) µm; normal for age of 14 years is 297 [IQR 229, 384] μm. The peritoneum biopsy did not show specific EPS findings, as the mesothelial cells were intact, and there was a lack of fibrin exudation, neo-membrane, fibroblast proliferation, infiltration, or calcification. Conclusions: While the biopsy was reassuring with respect to the absence of EPS, significant histopathological changes suggest that avoiding pH trauma may not ameliorate the effects of glucose exposure in long-term PD. [ABSTRACT FROM AUTHOR]

Aims: The present investigation was carried out to isolate, screen and characterize potential sulfur‐oxidizing bacteria (SOB) isolated from mustard field's soil. Methods and Results: A total of 130 bacteria were isolated and after screening five maximum sulfate‐producing isolates were optimized for culture conditions. The incubation time of 48 h was found optimum for all bacterial isolates and 30°C was the best temperature for the growth of SSD11, SSR1 and SSG8 whereas 35°C for SSF17. The pH 8 was found best for all four isolates except SSF17 (6 pH). Media having glucose as a carbon source and ammonium sulphate as an N‐source were producing maximum sulphate. The isolates SSF17, SSR1 and SSG8 were identified as Burkholderia cepacia (accession no. MT559819), Enterobacter cloacae (accession no. MT559820) and Klebsiella oxytoca (accession no. MT372097), respectively, on the basis of morphological, biochemical and molecular characterization. The isolates were also found to increase N and S uptake efficiently in both wheat and mustard crops. Conclusion: This study strongly concludes that SOB isolated from the mustard field can oxidize sulfur in vitro and in vivo conditions. The three best isolates come out of the study were identified as Burkholderia, Enterobacter and Klebsiella strains. Also, inoculation of SOB increased the uptake of S and N nutrient in mustard and wheat crops and thus may be proved as an important plant growth‐promoting bacteria having the biofertilization capability. Significance and Impact of the study: As we know, our soil is continuously deteriorating day by day due to excessive utilization and immoderate use of chemical fertilizers. The SOB could minimize the application of chemical fertilizers thus reducing environmental deterioration by improving soil health in sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Background: Bacterial infections are the commonest in both community and healthcare settings. Emergency of Extended Spectrum Beta-Lactamase producing Enterobacteriaceae has contributed to poor clinical outcomes. More efforts regarding antibiotic resistance have been dedicated to clinical settings and we do not know the extent of the catastrophe in community settings. We aimed at determining the burden, antimicrobial susceptibility patterns and molecular characteristics of Extended Spectrum Beta-Lactamase producing Enterobacteriaceae in agro-pastoral communities of Mbarara district, South Western Uganda. Methods: A laboratory based descriptive cross-sectional study was carried out among Enterobacteriaceae isolated from outpatients presenting with signs and symptoms of Urinary Tract Infections. Urine samples were delivered to Microbiology Laboratory of Mbarara University of Science and Technology for culture, identification, testing for ESBL production and Antibiotic Susceptibility Testing. Molecular characterization of ESBL producing Enterobacteriaceae was carried out at Medical and Molecular Laboratories Limited of Makerere University. Results: A total of 88 Enterobacteriaceae fulfilling the inclusion criteria were considered into the study. Escherichia coli 70.45% and Klebsiella pneumoniae 13.64% were the most isolated followed by Klebsiella oxytoca, Proteus mirabilis and Enterobacter aerogenes at 10.23%, 3.41% and 2.27% respectively. The production of ESBL was observed at 23.86%. Generally, high resistance rates were observed against Ampicillin 100%, Cefepime 100%, Aztreonam 95.24%, Nalidixic acid 90.48%, Ciprofloxacin 85.71% and Amoxicillin/clavulanate 80.95%. High rates of sensitivity were observed to Meropenem 95.24%, Imipenem 95.24%, Amikacin 95.24%, Gentamycin 90.48%, Cefoxitin 76.19% Piperacillin/tazobactam 80.95% and Nitrofurantoin 66. 67%. Multi-Drug Resistance (MDR) was observed at 85.71%. The most prevalent genes in ESBL producing Enterobacteriaceae were CTX-MU (Cefotaxime-Munich) 46.7%, TEM 30.00% and SHV (Sulfhydryl Reagent Variable) 23.3%. Conclusion: We demonstrated high prevalence, antibiotic resistance rates among Extended Spectrum Beta-Lactamase producing Enterobacteriaceae in the community. We recommend more community ESBL related studies and a One Health Approach to guide public health interventions. [ABSTRACT FROM AUTHOR]

Spontaneous pyogenic spondylodiscitis (SPS) is an uncommon disease. The most common causative organism of SPS is Staphylococcus aureus, followed by Gram-negative bacilli in 4%–30% of the cases. Polymicrobial SPS is very rare, with only a few cases reported in the literature. We report a case of polymicrobial SPS in a 43-year-old male who was recently diagnosed with autoimmune hepatitis with cirrhosis of the liver and presented with a 1-month history of progressive low backache with radiation to both the legs. Initially, he was managed as a case of Pott's spine with antitubercular therapy on the basis of immunocompromised status with positive ascitic fluid Mycobacterium tuberculosis polymerase chain reaction. However, due to lack of clinical and radiological response after 6 weeks, he underwent computed tomography-guided biopsy of the affected region. The culture from the biopsy specimen yielded Klebsiella oxytoca and Proteus vulgaris. He was managed with culture-sensitive antimicrobials. To the best of our knowledge, this is the first case of polymicrobial SPS caused by K. oxytoca, P. vulgaris, and M. tuberculosis. [ABSTRACT FROM AUTHOR]

Objective: Silybin and curcumin have potential antimicrobial effects. This study aimed to evaluate the synergistic antimicrobial effects of silybin and curcumin on virulence and carbapenemase genes expression among multidrug-resistant (MDR) Klebsiella oxytoca. Results: A total of 70 MDR K. oxytoca (carrying blaIMP and blaOXA-48-like genes) were included. The antibiotic susceptibility and biofilm production of isolates were determined. The silybin and curcumin at concentrations 10–500 mg/mL alone and in combination were exposed to bacterial isolates in Mueller Hinton broth medium for 24 h. The expression of blaIMP, blaOXA-48-like, mrkA, pilQ, matB and fimA genes was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). The mean minimum inhibitory concentration (MIC) of curcumin and silybin were 250 mg/mL and 500 mg/mL, respectively. The anti-virulent effect of 100 mg/mL of silybin and curcumin was shown by significant reduction in the expression of fimA (2.1-fold, P < 0.0001) and mrkA (2.1 fold, P < 0.0001) genes. Moreover, these compounds significantly decreased the expression of blaIMP1 (3.2-fold, P < 0.0001) gene. Notably, there was no significant effect on pilQ, matB and blaOXA-48-like genes. The results showed that silybin and curcumin can be candidate as natural way for control the MDR virulent strains of K. oxytoca. [ABSTRACT FROM AUTHOR]

Mobile genetic elements (MGEs) carrying antibiotic resistance genes (ARGs) disseminate ARGs when they mobilise into new bacterial hosts. The nature of such horizontal gene transfer (HGT) events between human gut commensals and pathogens remain poorly characterised. Here, we compare 1354 cultured commensal strains (540 species) to 45,403 pathogen strains (12 species) and find 64,188 MGE-mediated ARG transfer events between the two groups using established methods. Among the 5931 MGEs, we find 15 broad host range elements predicted to have crossed different bacterial phyla while also occurring in animal and environmental microbiomes. We experimentally demonstrate that predicted broad host range MGEs can mobilise from commensals Dorea longicatena and Hungatella hathewayi to pathogen Klebsiella oxytoca, crossing phyla simultaneously. Our work establishes the MGE-mediated ARG dissemination network between human gut commensals and pathogens and highlights broad host range MGEs as targets for future ARG dissemination management. Here, Forster et al. compare 1354 cultured commensal strains (540 species) to 45,403 pathogen strains (12 species), identifying 64,188 MGE-mediated antibiotic resistance gene transfer events between the two groups, and show that 15 broad host range MGEs are able to transfer between phyla. [ABSTRACT FROM AUTHOR]

The high global bacterial infection burden has created need to investigate the neglected potential drivers of pathogenic bacteria, to inform disease prevention. Kampala is facing a proliferation of herbalists, selling herbal medicine (HM), of largely unregulated microbiological quality. We evaluated the bacterial contamination burden in HM sold in Kampala, to support evidence-based redress. The total viable loads (TVL), total coliform counts (TCC), E. coli counts, and prevalence of selected bacterial strains in 140 HM were examined using conventional culture, following the guidelines of World Health Organization (WHO), and Uganda National Drug Authority (NDA). Data were analyzed using D'Agostino-Pearson test, frequencies, proportions, Chi-square, and Mann–Whitney U test with STATA version-15.0. Fifty (35.7%), fifty-nine (42.1%), and twelve (8.6%) HM were unsafe for human use because they exceeded WHO's permissible limits for TVL, TCC, and E. coli counts respectively. Solids had significantly higher mean TVL than liquids. Violation of NDA's guidelines was significantly associated with high TVL. Fifty-nine bacteria, viz., Klebsiella pneumoniae (n = 34; 57.6%), Escherichia. coli (12; 20.3%), Staphylococcus aureus (7; 11.9%), Klebsiella oxytoca (3; 5.1%), Bacillus cereus, Pseudomonas aeruginosa, and Enterobacter spp. (1; 1.7% each), were isolated from 45 (32.1%) samples. These bacteria can cause severe clinical diseases, and promote deterioration of HM potency. [ABSTRACT FROM AUTHOR]

The presence of heavy metals (HMs) in the environment represents a serious environmental problem. In this regard, this work was conceived with the aim of finding, among indigenous microorganisms, the species and their combinations with the best biosorption activity for the following HMs: zinc, lead, cadmium, copper, and nickel. The experiment was carried out in several steps: (1) isolation and identification of microbial strains from the Central Effluent Treatment Plant's wastewater; (2) studying the interaction of microorganisms and the ability to form biofilms in 96-well plates; (3) testing the resistance of biofilms to HMs; (4) testing the growth of biofilms on AMB media carriers in the presence of HMS; and (5) biosorption assay. The selected strains used in this study were: Enterobacter cloacae, Klebsiella oxytoca, Serratia odorifera, and Saccharomyces cerevisiae. The best biofilm producers in control medium were K. oxytoca/S. odorifera (KS), followed by K. oxytoca/S. odorifera/S. cerevisiae (KSC), and E. cloacae/K. oxytoca/S. odorifera (EKS) after 10 days of incubation. Mixed cultures composed of three species showed the highest resistance to the presence of all tested metals. The best biosorption capacity was shown by KSC for Cu2+ (99.18%), followed by EKS for Pb2+ (99.14%) and Cd2+ (99.03%), K. oxytoca for Ni2+ (98.47%), and E. cloacae for Zn2+ (98.06%). This research offers a novel approach to using mixed biofilms for heavy metal removal processes as well as its potential application in the bioremediation of wastewater. [ABSTRACT FROM AUTHOR]

Objective: To determine prevalence, causative organisms and sensitivity patterns of urinary1tract infections in febrile children. Study Design: Cross Sectional study. Setting: National Institute of Child Health, Karachi. Period: Jan 2019 to July 2019. Material & Methods: Patients from 3.0 to 14.0 years of age of either sex with complain of fever of >37.5 C for less than 2.0 weeks were included. Patients who have life threatening conditions, chronically ill, received antibiotics within 48 hours or had structural abnormalities of urinary tract like posterior ureteral valves and children with renal failure were excluded from study. Urinary sample was collected following aseptic measures of febrile children ad was sent to lab for culture and sensitivity within one hour of its collection. Sensitivity pattern was measured in lab via disc diffusion method. Data was analyzed using SPSS version 22. Results: The mean age was 8.6±3.3 years out of which 115 (65.7%) were male and 60 (34.3%) were females, mean duration of illness was 8.7±3.1 days. The frequency of culture positive UTI in febrile children was 21 (12%) cases. The common pathogen isolated from the urine culture was E. coli found in 10 cases followed by Klebsiella oxytoca. Overall 70% of E. coli are sensitive to. gentamicin and amikacin, 50% were sensitive to third generation cephalosporin, 60% of Klebsiella are sensitive to third generation cephalosporin, 60% resistant to gentamicin and amikacin and 80% were resistant to ampicillin. Conclusion: It was concluded from this study that the frequency of culture positive urinary tract infections in febrile children was 12% and common pathogen was E.coli followed by klebsilla oxytoca. [ABSTRACT FROM AUTHOR]

Antimicrobial resistant genes (ARG) are beginning to be recognized as contaminants of aquatic environments worldwide since they can be released through human activities and animal waste. Carbapenems are antibiotics used as a last resort in treating serious infections caused by multi-drug resistant bacteria. These bacteria produce enzymes that break down various antibiotics, such as penicillins and cephalosporins, rendering them ineffective. In the United States (U.S.), the most commonly found carbapenemase is the Klebsiella pneumoniae carbapenemase (KPC). The purpose of this pilot study was to analyze water samples, selected at three sites, from a segment of the Rio Grande River between El Paso, Texas, and Ciudad Juarez, Mexico, for the presence of KPCs using three different methods: first, chromogenic agar to screen for carbapenemase production and then polymerase chain reaction (PCR) and isothermal loop mediated amplification (LAMP) to confirm the presence of the KPC gene. Out of 28 bacterial isolates cultured in CHROMagar™ KPC, approximately a third (11/28) were positive for KPC production. Bacterial isolates included Citrobacter freundii complex (1 isolate), Klebsiella oxytoca (2 isolates), and Klebsiella pneumoniae (8 isolates). All 11 isolates that were screened through ChroMagar™ KPC also demonstrated the presence of KPC genes through PCR and LAMP. Most of the carbapenem resistant organisms were obtained from Site 3, where recreational activities occur during the summer months. The Rio Grande River runs between the border of the U.S. and Mexico. In the U.S., water from the river is used for irrigation and drinking water, whereas on the Mexican side, families use the river for recreational purposes. The presence of resistant bacteria in this segment of the river may represent a health concern. Public health programs need to be developed to prevent ARG transfer to humans and assess antibiotic resistance (AR) contamination in the ecosystem. [ABSTRACT FROM AUTHOR]

Simple Summary: Klebsiella oxytoca, as a type of plant growth-promoting rhizobacteria (PGPR), was studied with regards to promoting plant growth and inducing plant systemic resistance against Potato Virus Y (PVY). The results of greenhouse experiments with tobacco and potato plants demonstrated that treatments with the Klebsiella oxytoca and biochar significantly enhanced the growth, while clearly lowering the disease severity and concentration of PVY. An RT-PCR analysis of the defense genes in the tobacco and potato treated with the Klebsiella oxytoca and biochar revealed an association with enhancing the systemic resistance of tobacco and potato to PVY. Klebsiella oxytoca and biochar may be considered valuable options to control PVY in potato and other Solanaceae crops. Potato Virus Y (PVY) is a serious potato disease that may significantly decrease potato production. To suppress potato virus infection, several measures have been undertaken. The utilization of plant growth-promoting rhizobacteria is one of these methods. Biochar soil treatment is believed to provide plants with a number of advantages, including increased plant growth and the development of systemic resistance to a variety of plant diseases. The goal of this research was to see whether adding biochar and Klebsiella oxytoca to the soil might cause PVY resistance and enhance the involved mechanisms in PVY resistance. Potato and tobacco seedlings treated with Klebsiella oxytoca and biochar exhibited the same impact of significant symptom reduction, with complete negative ELISA findings, supporting the antiviral activity of K. oxytoca and biochar. Furthermore, owing to the connection between the ISR implicated substrates, significant amounts of polyphenol oxidase, catalase, and superoxide dismutase were observed in treated plants, with the same behavior as defense genes expression levels. It may be a step forward in the development of biochar and K. oxytoca as potential environmentally friendly disease control strategies against PVY. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the prevalence, risk factors of intestinal carbapenem-resistant Enterobacteriaceae (CRE) colonization and bloodstream infection (BSI) caused by CRE in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Methods: We analyzed the clinical data of 185 patients with hematological malignancies who underwent allo-HSCT from May 2019 to December 2021. All patients received regular CRE monitoring by rectal swab during allo-HSCT, and some CRE strains were further identified for carbapenemase phenotypes. The rates, distribution and risk factors of CRE colonization, CRE-induced BSI were analyzed. Results: CRE was detected in 44 of 185 recipients, with colonization rate of 23.8%. A total of 46 strains of CRE were isolated, including 22 Escherichia coli, 17 Klebsiella pneumoniae, three Klebsiella oxytoca, two Enterobacter hormaechei, and two other Enterobacteriaceae. Among the 19 strains identified with carbapenemase phenotypes, eight strains of E. coli produced metal β-lactamase, five K. pneumoniae produced serine carbapenemase, two K. pneumoniae produced metal β-lactamase, two K. oxytoca produced metal β-lactamase, a Citrobacter malonic acid-free produced metal β-lactamase and a Citrobacter freundii produced metal β-lactamase. In 10 patients developed with CRE-related BSI, the types and combined drug sensitivity of strains detected by rectal swab were highly consistent with blood culture. Multivariate analysis revealed that pulmonary infection, perianal infection and carbapenem application in the 3 months pre-transplant were independent risk factors for rectal CRE colonization, while rectal colonization with carbapenem-resistant K. pneumoniae (CR-KP) was an independent risk factor for CRE-induced BSI. The mortality rate within 30 days of CRE-related BSI was 50.0%, and patients receiving multi-drug therapy within 24 hours showed slightly lower mortality than that in the single-drug treatment group. Conclusion: Allo-HSCT patients with CRE-induced BSI have poor prognosis, and CR-KP rectal colonization is an independent risk factor for CRE-related BSI. Rectal swab screening during allo-HSCT could provide early warning for later CRE-induced BSI. [ABSTRACT FROM AUTHOR]

Feruloyl esterase (FAE)-producing micro-organisms to obtain ferulic acid (FA) from natural substrates have good industrial prospects, and the synergistic effect of multiple bacteria can better improve the yield of FA. In this study, on the premise of the synergistic effect of FAE, hemicellulose, and cellulase, the key strain Klebsiella oxytoca Z28 with FAE was combined with CMCase and Xylanase-producing strains to produce FA. The combination of strains with higher FA production are Klebsiella oxytoca Z28, Klebsiella pneumoniae JZE, Bacillus velezensis G1, and their FA production can reach 109.67 μg/g, which is 15% higher than that of single bacteria. To explore the effects of temperature, Ph, inoculum amount, distillers grains concentration and fermentation time on the FAE activity of the combination of strains in the fermentation process, and determined that temperature, Ph, and fermentation time were the main influencing factors and optimized through orthogonal design. The optimized fermentation conditions are 34 °C, Ph 8.0, and fermentation days for 6 days, the FAE activity can reach 270.78 U/L, and the FA yield of the combined strain is 324.50 μg/g, which is 200% higher than that of single-strain fermentation. [ABSTRACT FROM AUTHOR]

L -methionine-γ-lyase (MGL) producing bacterial isolates were screened from soil samples that further characterized as ' Klebsiella oxytoca BLM-1' by biochemical and 16S rDNA sequencing. Intracellular MGL obtained from K. oxytoca BLM-1 by sonication was purified by Octyl-Sepharose and Sephadex G-200 column chromatography. MALDI-TOF-MS analysis of protein band (M r ~ 63 kDa) confirmed the PLP-dependence and structural similarity with MGL enzyme. Purified MGL (1.1 μg) exhibited the maximum activity in potassium phosphate buffer (80 mM; with L -met 20 mM pH 7.0) at 37 °C. That further enhanced in the presence of NaCl (2 mM), Tween-80 (1.0 %; v/v) and EDTA (5 mM). K m and V max for purified MGL by using L -met as substrate was found to be 5.32 mM and 0.386 U/mL/min. The purified MGL showed PLP dependence and the half-life was 365.59 min. The MGL was effective against breast cancer (MCF7), gastric adenocarcinoma and human glioblastoma (U87MG) cancer cell lines with IC 50 values of purified MGL 0.041 U/mL, 0.008 U/mL and 0.009 U/mL, respectively. The U87MG, greatly affected by MGL treatment, when cultured in DMEM medium (10 mL) with PLP, homocysteine and 10 % FCS as compared to control/untransformed mouse spleen cells. [Display omitted] • Screening of MGL-producing bacterial isolate(s) by double-layer plate assay method. • Intracellular MGL released by cost-effective ultrasonication method. • MGL was effective against MFC-7, AGS and U87MG cell lines with 0.041 U/mL, 0.008 U/mL and 0.009 U/mL, IC50 values respectively. [ABSTRACT FROM AUTHOR]

Objectives: Little is known about IMP-producing Enterobacterales (IMP-Ent) in Europe. We analyzed at genomic and phenotypic level IMP-Ent isolates circulating in Spain in a 9-year period. Materials and methods: IMP-Ent isolates submitted to our reference laboratory were included. Antibiotic susceptibility was performed using microdilution method (EUCAST), and IMP-carbapenemase activity was measured with carbapenemase inhibitors, the ß-CARBA method, the modified Hodge test (MHT), and the modified carbapenemase inhibition method (mCIM). All isolates collected were sequenced for high-resolution single-nucleotide polymorphism (SNP) typing, core genome multilocus sequence typing (cgMLST), and resistome analysis. Results: Fifty IMP-Ent isolates, collected from 19 hospitals in 13 Spanish provinces, were detected: Klebsiella pneumoniae (IMP-Kpn) (24; 48%), Enterobacter roggenkampii (13; 26%), Enterobacter hormaechei (8, 16%), Klebsiella oxytoca (two; 4%), Enterobacter asburiae (one, 2%), Serratia marcescens (one; 2%) and Escherichia coli (one; 2%). All isolates were positive by the MHT and ß-CARBA tests; 48 (96%) were mCIM positive; 12 (24%) and 26 (52%) displayed positive inhibition with dipicolinic (meropenem) and EDTA (ertapenem), respectively. Five IMP-carbapenemase types were identified: IMP-8 (22; 44%), IMP-22 (17; 34%), IMP-13 (7; 14%), IMP-28 (two; 4%), and IMP-15 (two; 4%), predominating IMP-8 in K. pneumoniae and IMP-22 in E. roggenkampii. IMP-28 was exclusively identified in K. oxytoca and IMP-15 in E. hormaechei. Predominant STs were ST405 (29.2%), ST15 (25%) and ST464 (20.8%) in IMP-Kpn; ST96 (100%) in E. roggenkampii and ST182 (62.5%) in E. hormachei. Colistin and amikacin were the most active non-carbapenem antibiotics against IMP-Ent. Conclusion: IMP-Ent isolates remain infrequent in Spain, although in recent years have been circulating causing nosocomial outbreaks, being IMP-8-producing K. pneumoniae and IMP-22-producing E. roggenkampii the most frequently detected in this study. Inhibition with EDTA or dipicolinic acid presented false negative results in some IMP-producing strains. Active microbiological and molecular surveillance is essential for a better comprehension and control of IMP-Ent dissemination. [ABSTRACT FROM AUTHOR]

The treatment of chemical and biological contaminants in water through bio‐fabricated metal nanoparticles is one of the promising sustainable methods. Herein, an efficient synthesis of novel chromium oxide nanorods is introduced by Illicium verum fruit extract as a bio‐reducing, capping, and stabilizing agent. The morphological, optical, catalytic, and bactericidal properties of nanorods are investigated by various techniques. The UV–visible spectra displayed strong absorption peak in the region of 309.8 nm, whereas Fourier transform infrared presented the characteristic vibrations at 605.65 and 651.94 cm−1 attributed to CrO binding mode. Scanning electron microscopy results showed that chromium oxide nanoparticles are well‐dispersed with small rod‐shaped morphology. The average size of nanorods was found to be ~15 to 20 nm in length. Due to their ultra‐large surface area and strong π–π interaction, the plant‐coated nanorods were tested for the catalytic removal of methyl orange (MO), a common water‐soluble textile dye. Adsorption potential of Cr2O3 nanoparticles was monitored by UV–visible spectrophotometer, which showed 90–95% successive decrease in the absorption maxima of aqueous MO (1 μM). The elimination rate of MO was drastically improved from 45 to 30 min, while a combination of Cr2O3 nanorods and sodium borohydride NaBH4 was used. Bactericidal activities of these nanorods were tested against vast number of Gram‐positive and Gram‐negative bacteria. The significant results were obtained with 27 mm zone of inhibition against Klebsiella. oxytoca and Serratia. marcescens. This quick and simple procedure can be scaled up for commercial applications of new, eco‐friendly, and cost‐effective water treatment process. [ABSTRACT FROM AUTHOR]

Klebsiella spp. are gram-negative bacteria that are considered serious public health problems causing urinary tract infections, bloodstream infections, pneumonia infections, and soft tissue infections. This study was designed to investigate the prevalence of Klebsiella oxytoca (K. oxytoca) among clinical samples and determine their resistance against various antimicrobial medicines with molecular identification of K. oxytoca by polymerase chain reaction (PCR) technique using a specific sequence of pehX gene. A total of 250 clinical samples including throat, wound, and vaginal swabs were obtained. Participants were of both genders and different ages. The samples were streaked on the blood and MacConkey agars. Antibiotic sensitivity test was made by modified Kirby-Bauer disc diffusion technique. Molecular identification of K. oxytoca was performed for all isolates. Out of 250 clinical samples, K. oxytoca was reported in 32 (12.8%) cases. The highest prevalence was observed in 18(18%) cases of throat swabs, 16 (16%) cases of wound swabs, and 6 (6%) cases of vagina swabs. By the way, female cases were more affected 22 (14.5%) with K. oxytoca than male cases 10 (10.10%). Infected participants aged 15-40 years were more affected with K. oxytoca (23, 12.73%) compared to patients aged 41-65 years (9, 9.67%). The highest resistance pattern of K. oxytoca was 100% against Augmentin, Ampicillin, Cephalothin, Piperacillin, and Rifampin on one hand, and 62.50%, 59.37%, 53.12%, 53.12%, and 50% against Ceftazidime, Cefixime, Cefotaxime, Trimethoprim, and Aztreonam on the other hand, respectively. The highest sensitivity was observed against Amikacin and Imipenem (9.37%) and it was 21.87%, 21.87%, 25%, 25%, 28.12%, 28.12%, and 28.12% against Meropenem, Chloramphenicol, Nalidixic acid, Ciprofloxacin, Tobramycin, Gentamicin, and Doxycycline, respectively. Through molecular identification of K. oxytoca, all isolates showed a PCR product with 344-bp specific primer (pehX) that performed the K. oxytoca. [ABSTRACT FROM AUTHOR]

Klebsiella oxytoca NG13 was isolated from the rice rhizosphere in the early 1980s, and its nitrogen-fixing ability has been investigated. For the further advanced research, we sequenced its genome. NG13 contains one chromosome of 5,897,538 bp and no plasmid. NG13 should be classified to Klebsiella pasteurii based on ANI.

Objectives: This study describes the detection and tracking of emergency neurosurgical cross-transmission infections with carbapenem-resistant Klebsiella oxytoca (CRKO)., Methods: We conducted an epidemiological investigation and a rapid screening of 66 surveillance samples using the chromogenic selective medium. Two CRKO isolates from infected patients and three from the preoperative shaving razors had similar resistance profiles identified by the clinical laboratory., Results: The whole genome sequencing (WGS) results identified all isolates as Klebsiella michiganensis (a species in the K. oxytoca complex) with sequence type 29 (ST29) and carrying resistance genes bla KPC-2 and bla OXY-5 , as well as IncF plasmids. The pairwise average nucleotide identity values of 5 isolates ranged from 99.993% to 99.999%. Moreover, these isolates displayed a maximum genetic difference of 3 among 5,229 targets in the core genome multilocus sequence typing scheme, and the razors were confirmed as the contamination source. After the implementation of controls and standardized shaving procedures, no new CRKO infections occurred., Conclusion: Contaminated razors can be sources of neurosurgical site infections with CRKO, and standard shaving procedures need to be established. Chromogenic selective medium can help rapidly identify targeted pathogens, and WGS technologies are effective mean in tracking the transmission source in an epidemic or outbreak investigation. Our findings increase the understanding of microbial transmission in surgery to improve patient care quality., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Jiang, Lyu, Liu, Li, Liu, Tai, Hu, Zhang, Chu, Zhao, Huang and Wu.)

Eradication of Helicobacter pylori has contributed to the treatment of peptic ulcers and mucosa-associated lymphoid tissue lymphoma. Moreover, it has possibly decreased the prevalence of gastric cancer. However, eradication therapy is associated with various adverse effects, of which diarrhea is the most common. The incidence of diarrhea after eradication treatment varies from 8% to 48%. In particular, the incidence is higher in patients who receive first-line standard triple therapy compared with those who receive second-line therapy. Both antibiotics and proton pump inhibitors, components of eradication therapy, have short-term and long-term impacts on gut microbiota. The alterations of gut microbiota may not recover until 1 year after eradication therapy. Most cases of diarrhea that occur after eradication therapy are antibiotic-associated diarrhea caused by the destruction of the normal gut microbiota. In some cases, Clostridioides difficile-associated diarrhea occurs after eradication therapy. If bloody diarrhea occurs after eradication therapy and the Clostridioides difficile toxin is not detected, antibiotic-associated hemorrhagic colitis associated with Klebsiella oxytoca infection should be suspected. It is crucial to explain the possibility of diarrhea before initiating eradication therapy to increase compliance. Furthermore, probiotics may be administered to reduce diarrhea. If severe diarrhea or symptoms other than the usual antibiotic-associated diarrhea occur during or after eradication therapy, antibiotics should be discontinued. In addition, appropriate tests to determine the cause of diarrhea should be performed. This review summarizes the alteration of the gut microbiota, the causes of diarrhea after Helicobacter pylori eradication therapy, and its management.

Mingyue Sun, Weiqiang Xiao, Qingxia Xu Department of Clinical Laboratory, Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Zhengzhou, Henan, People’s Republic of ChinaCorrespondence: Qingxia XuDepartment of Clinical Laboratory, Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Dongming Road No.127, Zhengzhou, Henan Province, People’s Republic of ChinaTel +860371-65587147Email qxiaxu@126.comPurpose: Klebsiella oxytoca is an opportunistic pathogen causing nosocomial infections. This study was designed to characterize the genomic features of a carbapenem-resistant K. oxytoca strain and analyze its molecular characteristics.Materials and Methods: The strain wzx-IMP was isolated from the blood of a 2-year-old girl diagnosed with acute myeloid leukemia-M7. Species identification was performed, and the minimal inhibitory concentration of the strain was measured. Multilocus sequence typing was performed to identify the subtypes of K. oxytoca. The transfer capacity of the blaIMP-4-harboring plasmid was investigated by conjugation experiments, and the genome characteristics of the strain were examined using whole-genome sequencing.Results: wzx-IMP belongs to the ST85 type and is resistant to imipenem and meropenem, which harbored the blaIMP-4 gene. The blaIMP-4 gene was located in an IS26-associated class 1 integron of pwzx_IMP, which contains conserved IncN1-type backbone regions with a replication gene and its accessory structure for plasmid replication. The blaIMP-4-carrying plasmid in wzx-IMP was successfully transferred to Escherichia coli EC600 by conjugation. Whole-genome sequencing showed that the wzx-IMP isolate included the blaOXY-1-1 gene, accompanied by OmpK36 absence.Conclusion: We report an ST85-type carbapenem-resistant K. oxytoca strain, which produces blaIMP-4 located in an IncN1-type plasmid and accompanied by OmpK36 porin deficiency.Keywords: Klebsiella oxytoca, blaIMP-4, ST85, IncN1, OmpK36

Background: Infections caused by Klebsiella oxytoca are the second most common cause of Klebsiella infections in humans. Most studies have focused on K. oxytoca outbreaks and few have examined the broader clinical context of K. oxytoca.Methods: Here, we collected all clinical isolates identified as K. oxytoca in a hospital microbiological diagnostic lab across a 15-month period (n = 239). Whole genome sequencing was performed on a subset of 92 isolates (all invasive, third-generation cephalosporin resistant (3GCR) and non-urinary isolates collected > 48 h after admission), including long-read sequencing on a further six isolates with extended-spectrum beta-lactamase or carbapenemase genes.Results: The majority of isolates were sensitive to antimicrobials, however 22 isolates were 3GCR, of which five were also carbapenem resistant. Genomic analyses showed those identified as K. oxytoca by the clinical laboratory actually encompassed four distinct species (K. oxytoca, Klebsiella michiganensis, Klebsiella grimontii and Klebsiella pasteurii), referred to as the K. oxytoca species complex (KoSC). There was significant diversity within the population, with only 10/67 multi-locus sequence types (STs) represented by more than one isolate. Strain transmission was rare, with only one likely event identified. Six isolates had extended spectrum beta-lactamase (blaSHV-12 and/or blaCTX-M-9) or carbapenemase (blaIMP-4) genes. One pair of K. michiganensis and K. pasteurii genomes carried identical blaIMP-4 IncL/M plasmids, indicative of plasmid transmission.Conclusion: Whilst antimicrobial resistance was rare, the resistance plasmids were similar to those found in other Enterobacterales, demonstrating that KoSC has access to the same plasmid reservoir and thus there is potential for multi-drug resistance. Further genomic studies are required to improve our understanding of the KoSC population and facilitate investigation into the attributes of successful nosocomial isolates. [ABSTRACT FROM AUTHOR]

Artisanal cheeses are produced in small-scale production plants, where the lack of full automation and control of environmental and processing parameters suggests a potential risk of microbial contamination. The aim of this study was to perform a longitudinal survey in an Italian artisanal factory producing a spreadable soft cheese with no rind to evaluate the inter- and intra-batch variability of physicochemical and microbial parameters on a total of 720 environmental and cheese samples. Specifically on cheese samples, the evaluation was additionally performed on physicochemical parameters. Cheese samples were additionally collected during 15 days of storage at constant temperatures of 2 and 8 °C, as well as a dynamic profile of 2 °C for 5 days and 8 °C for 10 days. Furthermore, Enterobacteriaceae isolates were identified at species level to have a better knowledge of the environmental and cheese microbiota potentially harboring human pathogens. High interbatch variability was observed for lactic acid bacteria (LAB) and total bacteria count (TBC) in cheese at the end of production but not for pH and water activity. A temperature of 8 °C was associated with a significantly higher load of Enterobacteriaceae in cheeses belonging to batch 6 at the end of storage, and this temperature also corresponded with the highest increase in LAB and TBC loads over cheese shelf life. Results from generalized linear mixed models (GLMMs) indicated that drains in the warm room and the packaging area were associated with higher levels of TBC and Enterobacteriaceae in cheese. Regarding foodborne pathogens, no sample was positive for verotoxigenic Escherichia coli (VTEC) or Listeria monocytogenes, whereas six Staphylococcus aureus and one Salmonella pullorum isolates were collected in cheese samples during storage and processing, respectively. Regarding Enterobacteriaceae, 166 isolates were identified at species level from all batches, with most isolates belonging to Klebsiella oxytoca and pneumoniae, Enterobacter cloacae, Hafnia alvei, and Citrobacter freundii evidencing the need to focus on standardizing the microbial quality of cow milk and on hygienic procedures for cleaning and disinfection especially in warm and maturation rooms. Further studies should be performed to investigate the potential pathogenicity and antimicrobial resistance of the identified Enterobacteriaceae species in artisanal cheeses. [ABSTRACT FROM AUTHOR]

2,3-Butanediol (2,3-BDO) is a functional C 4 compound with various industrial applications. It exists as three isomers, and racemic mixtures can be produced through chemical synthesis and fermentation using natural producers. In this study, Saccharomyces cerevisiae was engineered to produce enantiopure meso-2,3-BDO by eliminating BDH1 encoding (2 R,3 R)-butanediol dehydrogenase and introducing budC coding for acetoin reductase from Klebsiella oxytoca. The resulting strain produced 69.2 g/L of enantiopure meso-2,3-BDO production with a productivity of 1.5 g meso-2,3-BDO/L•h using cassava hydrolysates. Furthermore, improved titer and productivity of meso-2,3-BDO were achieved by resolving C 2 -auxotrophy. To decrease the acetoin accumulation, the budC gene was stably and strongly expressed throughout the chromosomal integration. The resulting strain produced 171 g/L of meso-2,3-BDO with 0.49 g meso-2,3-BDO /g glucose, which is 99.8 % of theoretical yield and a productivity of 1.8 g meso-2,3-BDO/L•h. These results will help facilitate the commercial production of enantiopure meso-2,3-BDO using the GRAS strain. • Pdc-deficient S. cerevisiae produced (R)-acetoin by disrupting BDH1. • Introducing budC from K. oxytoca enabled enantiopure meso-2,3-BDO production. • The strain produced 69.2 g/L of meso-2,3-BDO from cassava hydrolysates. • 171 g/L of enantiopure meso-2,3-BDO was produced by fed-batch fermentation. [ABSTRACT FROM AUTHOR]

Carbapenemase-producing Enterobacterales (CPE) raise concerns about the treatment options for infectious diseases and infection control. We conducted a multicenter study to clarify the molecular epidemiology of CPE in the Aichi Prefecture during the first 3-month period from 2015 to 2019. Carbapenemase production was screened using a modified carbapenem inactivation method, and the genotypes of the carbapenemase genes were determined by polymerase chain reaction sequencing. Genetic relatedness was analyzed using multilocus sequence typing (MLST). Twenty-four hospitals participated in this study. Of the 56,494 Enterobacterales strains detected during the study period, 341 (0.6%) that met the susceptibility criteria were analyzed. Sixty-five of the 341 strains were determined to be CPE, with an incidence rate of 0.12% (65/56,494). The bacterial species responsible for CPE were Klebsiella pneumoniae (n = 24), Enterobacter cloacae complex (n = 23), Klebsiella oxytoca (n = 10), and Escherichia coli (n = 8). Most of the carbapenemase genotypes were IMP-1 (58/65), and only three were IMP-6 types. Three E. coli strains that produced NDM-5 were detected. MLST analysis showed that Sequence type (ST) 78 was predominant in E. cloacae complex CPE (14/23, 60.9%). Meanwhile, various STs were detected in carbapenemaseproducing (CP) K. pneumoniae, of which ST37 and ST517 were the most common. The incidence rate of CPE in this region was comparable to national data. This 3-month surveillance revealed the spread of ST78 of CP E. cloacae complex and ST517 and ST592 of CP K. pneumoniae across hospitals, indicating the need to strengthen regional infection control programs. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the chemical composition of steam distillate essential oil and corresponding hydrolate obtained from S. officinalis grown in Serbia, as well as the influence of weather conditions (temperature and precipitations) on their chemical profiles. Furthermore, their antimicrobial activity was investigated in vitro. The main compounds in essential oil were cis-thujone, followed by camphor, trans-thujone, and 1,8-cineole, while hydrolate was slightly different from the essential oil, with camphor, cis-thujone, and 1,8-cineole as the main compounds. Among the eight respiratory-associated microorganisms, Klebsiella oxytoca was the most sensitive to the tested EOs (minimum inhibitory concentration (MIC)/minimal bactericidal/fungicidal concentration (MBC/MFC) were 14.20 and 28.4 μL mL−1, respectively). MIC and MBC values of other tested bacteria ranged between 28.40 and 227.25 μL mL−1 while for Candida albicans MIC/MFC ranged from 28.40/56.81 to 56.81–113.63 μL mL−1. Antibiotic susceptibility patterns for the analyzed eight respiratory-associated microorganisms showed an intermediate level of resistance to commonly used antibiotics such as ampicillin, levofloxacin, and ciprofloxacin. As a preliminary approach to the antimicrobial profiling of the tested EO, the obtained results revealed that the tested samples possess remarkable antibacterial activities and could be used to develop pharmaceutical formulations as an alternative to conventional antibiotic therapy. [ABSTRACT FROM AUTHOR]

A cross-sectional study was employed from March 2021 to October 2021 to isolate and identify Klebsiella species found in the gut of honey bees collected from worker of honey bee (Apis mellifera) from hives in Haramaya University bee farm, Damota and Finqile's, managed under traditional and modern beekeeping apiculture. From the selected farm, a total of 60 samples of live adult honey bees were collected purposively. The live adult worker of the honey bee was individually surface-sterilized and complete alimentary canals of the worker bee were dissected and processed for Klebsiella isolation. Descriptive statistics were used to describe the occurrence of Klebsiella species and the proportion of Klebsiella found in the gut was analyzed for the association with study variables by the Pearson chi-square test. The overall prevalence of Klebsiella spp. was 50% from samples. The prevalence of Klebsiella pneumoniae was 26.7% and that of Klebsiella oxytoca was 23.3% from isolated using bacteriological examined samples. The isolates were characterized for the antimicrobial susceptibility test using the disc diffusion method. Among the isolated colonies, Klebsiella pneumoniae had the highest resistance to ampicillin (84.2%) and showed less resistance to gentamycin and trimethoprim sulfamethoxazole (26.3%). Klebsiella oxytoca was highly resistant to ampicillin (54.5%) and erythromycin (54.5%) and showed low and equal resistance to gentamycin and amoxicillin (18.2%). Molecular characterization should be conducted to identify Klebsiella spp. from honey bees. Monitoring antimicrobial effectiveness is recommended to tackle the existing problem in apiculture farms, and its possible public health threat should be noted for community by public health professionals. [ABSTRACT FROM AUTHOR]

Background: 2,3-butanediol is an important platform compound which has a wide range of applications, involving in medicine, chemical industry, food and other fields. Especially the optically pure (2R,3R)-2,3-butanediol can be employed as an antifreeze agent and as the precursor for producing chiral compounds. However, some (2R,3R)-2,3-butanediol overproducing strains are pathogenic such as Enterobacter cloacae and Klebsiella oxytoca. Results: In this study, a (3R)-acetoin overproducing C. glutamicum strain, CGS9, was engineered to produce optically pure (2R,3R)-2,3-butanediol efficiently. Firstly, the gene bdhA from B. subtilis 168 was integrated into strain CGS9 and its expression level was further enhanced by using a strong promoter Psod and ribosome binding site (RBS) with high translation initiation rate, and the (2R,3R)-2,3-butanediol titer of the resulting strain was increased by 33.9%. Then the transhydrogenase gene udhA from E. coli was expressed to provide more NADH for 2,3-butanediol synthesis, which reduced the accumulation of the main byproduct acetoin by 57.2%. Next, a mutant atpG was integrated into strain CGK3, which increased the glucose consumption rate by 10.5% and the 2,3-butanediol productivity by 10.9% in shake-flask fermentation. Through fermentation engineering, the most promising strain CGK4 produced a titer of 144.9 g/L (2R,3R)-2,3-butanediol with a yield of 0.429 g/g glucose and a productivity of 1.10 g/L/h in fed-batch fermentation. The optical purity of the resulting (2R,3R)-2,3-butanediol surpassed 98%. Conclusions: To the best of our knowledge, this is the highest titer of optically pure (2R,3R)-2,3-butanediol achieved by GRAS strains, and the result has demonstrated that C. glutamicum is a competitive candidate for (2R,3R)-2,3-butanediol production. [ABSTRACT FROM AUTHOR]

Background: Coliform bacteria are major causative agents of bovine mastitis, a disease that has devastating effect on dairy animal health and milk production. This cross-sectional study, carried out in the North West region of Cameroon, sought to determine the prevalence of bovine mastitis, coliforms associated with bovine mastitis, risk factors for infection and the antibiotic resistance pattern of coliform bacterial isolates. Materials and methods: A total of 1608 udder quarters were sampled from 411 cows using a questionnaire, clinical examination, California Mastitis Test and milk culture. Primary isolation of coliform bacteria was done on MacConkey agar while identification of coliforms employed Gram-staining and biochemical testing. Each coliform bacterial isolate was challenged with 11 antibiotics using the Kirby-Bauer disc diffusion method. Results: The prevalence of mastitis was 53.0% (218/411) and 33.1% (532/1608) at the cow- and quarter-levels respectively. Overall, 21.9% (90/411) cows and 8.2% (132/1608) udder quarters showed coliform mastitis. Escherichia coli was isolated in 7.0% of mastitis milk, and other coliforms isolated were Enterobacter cloacae (12.6%), Klebsiella pneumoniae (2.4%), Enterobacter sakazakii (1.1%), Klebsiella oxytoca (0.8%), Citrobacter freudii (0.4%), Serratia ficaria (0.4%) and Serratia liquefaciens (0.2%). Lactation stage, breed, history of mastitis and moist/muddy faeces contaminated environment were significantly associated (P-value < 0.05) with coliform mastitis. Coliform isolates (99.0%; 203/205) were resistant to at least one antibiotic tested. Amoxicillin had the highest resistance (88.8%) while norfloxacin had the least resistance (3.4%). Multidrug resistance was exhibited by 52.7% (108/205) of the isolates in a proportion of 27.8% Enterobacter cloacae, 10.7% E. coli, 6.3% Klebsiella pneumoniae, 2.9% Enterobacter sakazakii, 2.0% Klebsiella oxytoca, 1.0% Citrobacter freundii, 1.0% Serratia ficaria, 0.5% Serratia liquefaciens and 0.5% Serratia odorifera. Conclusion: Results indicate a need to educate these dairy farmers about mastitis (particularly subclinical), proper hygiene methods in milking and the public health implications of consuming contaminated raw milk. [ABSTRACT FROM AUTHOR]

Background: Mastitis pathogenesis involves a wide range of opportunistic and apparently resident microorganims including bacteria, viruses and archaea. In dairy animals, microbes reside in the host, interact with environment and evade the host immune system, providing a potential for host-tropism to favor mastitis pathogenesis. To understand the host-tropism phenomena of bovine-tropic mastitis microbiomes, we developed a cow-to-mouse mastitis model. Methods: A cow-to-mouse mastitis model was established by fecal microbiota transplantation (FMT) and milk microbiota transplantation (MMT) to pregnant mice to assess microbiome dysbiosis and genomic functional perturbations through shotgun whole metagenome sequencing (WMS) along with histopathological changes in mice mammary gland and colon tissues. Results: The cow-to-mouse FMT and MMT from clinical mastitis (CM) cows induced mastitis syndromes in mice as evidenced by histopathological changes in mammary gland and colon tissues. The WMS of 24 samples including six milk (CM = 3, healthy; H = 3), six fecal (CM = 4, H = 2) samples from cows, and six fecal (CM = 4, H = 2) and six mammary tissue (CM = 3, H = 3) samples from mice generating 517.14 million reads (average: 21.55 million reads/sample) mapped to 2191 bacterial, 94 viral and 54 archaeal genomes. The Kruskal–Wallis test revealed significant differences (p = 0.009) in diversity, composition, and relative abundances in microbiomes between CM- and H-metagenomes. These differences in microbiome composition were mostly represented by Pseudomonas aeruginosa, Lactobacillus crispatus, Klebsiella oxytoca, Enterococcus faecalis, Pantoea dispersa in CM-cows (feces and milk), and Muribaculum spp., Duncaniella spp., Muribaculum intestinale, Bifidobacterium animalis, Escherichia coli, Staphylococcus aureus, Massilia oculi, Ralstonia pickettii in CM-mice (feces and mammary tissues). Different species of Clostridia, Bacteroida, Actinobacteria, Flavobacteriia and Betaproteobacteria had a strong co-occurrence and positive correlation as the indicator species of murine mastitis. However, both CM cows and mice shared few mastitis-associated microbial taxa (1.14%) and functional pathways regardless of conservation of mastitis syndromes, indicating the higher discrepancy in mastitis-associated microbiomes among lactating mammals. Conclusions: We successfully induced mastitis by FMT and MMT that resulted in microbiome dysbiosis and genomic functional perturbations in mice. This study induced mastitis in a mouse model through FMT and MMT, which might be useful for further studies- focused on pathogen(s) involved in mastitis, their cross-talk among themselves and the host. [ABSTRACT FROM AUTHOR]

Capturing the diverse microbiota from healthy and/or stress resilient plants for further preservation and transfer to unproductive and pathogen overloaded soils, might be a tool to restore disturbed plant–microbe interactions. Here, we introduce Aswan Pink Clay as a low-cost technology for capturing and storing the living root microbiota. Clay chips were incorporated into the growth milieu of barley plants and developed under gnotobiotic conditions, to capture and host the rhizospheric microbiota. Afterward, it was tested by both a culture-independent (16S rRNA gene metabarcoding) and -dependent approach. Both methods revealed no significant differences between roots and adjacent clay chips in regard total abundance and structure of the present microbiota. Clay shaped as beads adequately supported the long-term preservation of viable pure isolates of typical rhizospheric microbes, i.e. Bacillus circulans , Klebsiella oxytoca , Sinorhizobium meliloti , and Saccharomyces sp. up to 11 months stored at −20°C, 4°C, and ambient temperature. The used clay chips and beads have the capacity to capture the root microbiota and to long-term preserve pure isolates. Hence, the developed approach is qualified to build on it a comprehensive strategy to transfer and store complex and living environmental microbiota of rhizosphere toward biotechnological application in sustainable plant production and environmental rehabilitation. [ABSTRACT FROM AUTHOR]

One of the indispensable resources of the human being is water, but there are few populations that have this element in the purest way. In the urban area of Quindío have been several studies of the quality on drinking water, but not in the rural area. Therefore, we evaluate the water condition consumed by the rural population; In this case, some BD BBLD Crystal lab tests were performed for the identification of bacteria and IFI technique for parasites where were found 9 species of bacteria in which the most frequent were Enterobacter cloacae y Klebsiella oxytoca, 11 genre of parasites belonging to helminths and protozoa, Opisthorchis sp, Strongyloides sp, Giardia sp and 7 genre of algae. In spite of the fact that the values of physicochemical parameters were into the established limits according to the normativity, these conditions are allowing the growth of microorganisms in the water; most of them are causing various gastrointestinal diseases in humans, and the presence of these organisms suggest us that the consumed water by the rural population in the municipality of Circasia is not suitable for human consumption since it is evident the presence of bacteria, helminths and protozoa, and it does not comply with the condition of quality on drinking water. Thus, since it does not have a permanent treatment, water must be boiled before it is consumed. [ABSTRACT FROM AUTHOR]

The present study aimed at assessing the occurrence of microbiological hazards (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. and Escherichia coli O157) in an artisanal soft cheese produced in northern Italy. In the same product total bacterial count, lactic acid bacteria and Enterobacteriaceae were enumerated, and pH and water activity measured in two batches sampled in summer and winter. Samples of raw materials, environmental swabs from the production processes and cheese during 15 days of storage at 2 and 8°C as well as dynamic temperature of 2°C for 5 days and 8°C for 10 days were collected and tested. The load of total bacterial count was significantly higher in the winter batch in comparison to the summer one, with a significant increase at the end of the storage period also noticed for lactic acid bacteria. Statistical higher values of pH were registered in raw materials and end of storage in winter batch. S. aureus was confirmed only in the winter batch within samples (n=4) of stored cheese. On plates used for E. coli O157 detection, colonies of Klebsiella pneumoniae and Klebsiella oxytoca were isolated. The results suggest that the highest bacterial population in the winter batch was associated to a higher pH in stored cheese and a higher number of biological hazards identified. Their isolation started in the maturation room suggesting this step as relevant for possible cheese contamination. [ABSTRACT FROM AUTHOR]

Recent studies have revealed the connection between amino acid chirality and diseases. We have previously reported that the gut microbiota produces various D-amino acids in a murine acute kidney injury (AKI) model. Here, we further explored the pathophysiological role of D-alanine (D-Ala) in AKI. Levels of D-Ala were evaluated in a murine AKI model. We analyzed transcripts of the N-methyl-D-aspartate (NMDA) receptor, a receptor for D-Ala, in tubular epithelial cells (TECs). The therapeutic effect of D-Ala was then assessed in vivo and in vitro. Finally, the plasma level of D-Ala was evaluated in patients with AKI. The Grin genes encoding NMDA receptor subtypes were expressed in TECs. Hypoxic conditions change the gene expression of Grin1, Grin2A, and Grin2B. D-Ala protected TECs from hypoxia-related cell injury and induced proliferation after hypoxia. These protective effects are associated with the chirality of D-Ala. D-Ala inhibits reactive oxygen species (ROS) production and improves mitochondrial membrane potential, through NMDA receptor signaling. The ratio of D-Ala to L-Ala was increased in feces, plasma, and urine after the induction of ischemia-reperfusion (I/R). Moreover, Enterobacteriaceae, such as Escherichia coli and Klebsiella oxytoca, produce D-Ala. Oral administration of D-Ala ameliorated kidney injury after the induction of I/R in mice. Deficiency of NMDA subunit NR1 in tubular cells worsened kidney damage in AKI. In addition, the plasma level of D-Ala was increased and reflected the level of renal function in patients with AKI. In conclusion, D-Ala has protective effects on I/R-induced kidney injury. Moreover, the plasma level of D-Ala reflects the estimated glomerular filtration rate in patients with AKI. D-Ala could be a promising therapeutic target and potential biomarker for AKI. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the occurrence of integron-carrying coliform bacteria in the spring water of Warta river, a major river in Poland. We isolated 18 strains (12 Escherichia coli, three Pantoea sp., 2 Citrobacter freundii, and 1 Klebsiella oxytoca) harbouring class 1 and/or class 2 integrons. Class 1 integrons contained aadA1, dfrA7, dfrA17, dfrA1-aadA1, and dfrA17-aadA5 gene cassette arrays, whereas the genetic content of class 2 integrons was stable and consisted of sat2-aad1 gene cassette array. The strains carrying integrons were resistant to 4–11 antimicrobials, most frequently to sulfamethoxazole, ampicillin, piperacillin, trimethoprim, and trimethoprim/sulfamethoxazole. [ABSTRACT FROM AUTHOR]

Infections of the urinary tract have been on the rise globally and these are also worsened by the increasing rate of antibiotic resistance in uropathogens. This study aimed to determine the susceptibility profile of extended spectrum β-lactamase (ESBL)- producing uropathogens to selected antibiotics and their carriage of ESBL genes. Bacterial uropathogens were obtained from the urine bench of a Microbiology laboratory in a Teaching Hospital in South-West Nigeria. Susceptibility to antibiotics was tested using the disc diffusion method, while detection of ESBL production was done using the double disc synergy test (DDST). Detection of ESBL genes was performed by PCR. A total of 21 ESBL- producing uropathogens were obtained namely: Klebsiella pneumoniae (11), Klebsiella oxytoca (6), Proteus mirabilis (2), Enterobacter cloacae (1) and Pseudomonas aeruginosa (1). The resistance to antibiotics in the uropathogens was: imipenem (0%), gentamicin (38.1%), sulfamethoxazole-trimethoprim (52.4%), amoxicillin-clavulanate (61.9%), aztreonam (66.7%), ceftazidime (66.7%), tetracycline (90.5%), cefpodoxime (100%) and cefotaxime (100%). Altogether, 90.5% (19/21) of the isolates were multidrug resistant (MDR). Of the 21 uropathogens, 61.9% (13/21) carried bla CTX-M, 52.4% (11/21) carried bla TEM while bla SHV was detected in 47.6% (10/21) of the isolates. There was co-carriage of ESBL genes in 12 uropathogens. This study showed a high prevalence of multidrug resistance and a high carriage of ESBL genes in the ESBL- producing isolates obtained over the study period. There is a need for a review of antibiotic options in the treatment of UTI to clamp down on the ever-increasing tide of antibiotic resistance in uropathogens. [ABSTRACT FROM AUTHOR]

Antimicrobials in wastewater promote the emergence of antibiotic resistance, facilitated by selective pressure and transfer of resistant genes. Enteric bacteria belonging to Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Citrobacter species (n = 126) from hospital effluents and proximate wastewater treatment plant were assayed for susceptibility to four antimicrobial classes. The β-lactamase encoding genes harbored in plasmids were genotyped and the plasmids were sequenced. A multidrug resistance phenotype was found in 72% (n = 58) of E. coli isolates, 70% (n = 43) of Klebsiella species isolates, and 40% (n = 25) of Enterobacter and Citrobacter species. Moreover, 86% (n = 50) of E. coli, 77% (n = 33) of Klebsiella species, and 25% (n = 4) of Citrobacter species isolates phenotypically expressed extended spectrum β-lactamase. Regarding ESBL genes, blaCTX-M-27 and blaTEM-1 were found in E. coli, while Klebsiella species harbored blaCTX-M-15, blaCTX-M-30, or blaSHV-12. Genes coding for aminoglycoside modifying enzymes, adenylyltransferases (aadA1, aadA5), phosphotransferases (aph(6)-1d, aph(3″)-Ib), acetyltransferases (aac(3)-IIa), (aac(6)-Ib), sulfonamide/trimethoprim resistant dihydropteroate synthase (sul), dihydrofolate reductase (dfrA), and quinolone resistance protein (qnrB1) were also identified. Monitoring wastewater from human sources for acquired resistance in clinically important bacteria may provide a cheaper alternative in regions facing challenges that limit clinical surveillance. [ABSTRACT FROM AUTHOR]

Catheter-associated urinary tract infections (CAUTI) are a common clinical concern as they can lead to severe, persistent infections or bacteremia in long-term catheterized patients. This type of CAUTI is difficult to eradicate, as they are caused by multispecies biofilms that may have reduced susceptibility to antibiotics. Many new strategies to tackle CAUTI have been proposed in the past decade, including antibiotic combination treatments, surface modification and probiotic usage. However, those strategies were mainly assessed on mono- or dual-species biofilms that hardly represent the long-term CAUTI cases where, normally, 2–4 or even more species can be involved. We developed a four-species in vitro biofilm model on catheters involving clinical strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca and Proteus mirabilis isolated from indwelling catheters. Interspecies interactions and responses to antibiotics were quantitatively assessed. Collaborative as well as competitive interactions were found among members in our model biofilm and those interactions affected the individual species' abundances upon exposure to antibiotics as mono-, dual- or multispecies biofilms. Our study shows complex interactions between species during the assessment of CAUTI control strategies for biofilms and highlights the necessity of evaluating treatment and control regimes in a multispecies setting. [ABSTRACT FROM AUTHOR]