Do post-surgical multiresistant urinary infections occur in horses? Case of unilateral pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria as a complication of cystotomy.

Pyelonephritis is a serious condition that is rarely described in horses. In contrast, urinary tract infections are common in humans and small animals, and multi-drug-resistant urinary infections are an emerging threat. In this report, we describe a horse with unilateral pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria belonging to the Enterobacter cloacae complex. [Correction added on 9 August 2023, after first online publication: The preceding sentence was corrected.] An 11-year-old Swedish warmblood gelding was diagnosed with a cystolith and a cystotomy through an open left para-inguinal approach was performed. Seven days after surgery the horse presented with pyrexia, dullness and colic. Diagnostic testing and renal transabdominal ultrasonography confirmed the presence of a right-sided pyelonephritis. Culture and antimicrobial susceptibility testing revealed a pure growth of extended-spectrum beta-lactamases-producing E. cloacae complex bacteria with resistance against beta-lactams, aminoglycoside and trimethoprim-sulphonamide classes. Treatment included prolonged oral antimicrobials according to susceptibility testing results (enrofloxacin), judicious use of non-steroidal anti-inflammatory drugs, fluid therapy and gastric ulcer prophylaxis. The horse recovered successfully and is currently in good health (follow-up of 5 years). Once the infection resolved, unilateral renal scarring occurred. Multidrug-resistant upper-urinary infections occur in horses and should be considered in a post-surgical patient that develops fever. Early diagnosis, urine bacterial culturing and antimicrobial susceptibility testing were crucial in this case to successful management.

Disappearance and prevalence of extended-spectrum ß-lactamase-producing Escherichia coli and other coliforms in the wastewater treatment process.

Antibiotic-resistant bacteria (ARBs) can now be detected not only in clinical institutions but also in wastewater treatment plants (WWTPs), extending the range of emergence to residential areas. In this study, we investigated the change of antibiotic-resistant Escherichia coli (E. coli) and other coliforms in each treatment process at WWTPs. Throughout the treatment process, the numbers of E. coli and other coliforms were significantly reduced to less than 5.7 ± 0.5 CFU/100 ml and 2.4 ± 0.0×102 CFU/100 ml, respectively. However, ESBL-producing E. coli and other coliforms were detected in each treatment process (even after chlorination) at 5.6% and 4.8%, compared to the total E. coli and other coliforms counts. Then, ESBL-producing-related genes were identified via PCR analyses, and the most predominant gene was CTX-M-9 in both E. coli (47.2%) and other coliforms (47.3%). Although actual WWTPs greatly reduced the number of bacteria, the relative prevalence of ESBL-producing bacteria was increased, suggesting that ESBL-producing bacteria remain in the effluent at minimal concentrations and could be diffusing to water bodies.

Detection of extended-spectrum ß-lactamase-producing bacteria isolated directly from urine by infrared spectroscopy and machine learning.

Resistant bacteria have become one of the leading health threats in the last decades. Extended-spectrum ß-lactamase (ESBL) producing bacteria, including Escherichia (E.) coli and Klebsiella (K.) pneumoniae (the most frequent ones), are a significant class out of all resistant infecting bacteria. Due to the widespread and ongoing development of ESBL-producing (ESBL+) resistant bacteria, many routinely used antibiotics are no longer effective against them. However, an early and reliable ESBL+ bacteria detection method will improve the efficiency of treatment and limit their spread. In this work, we investigated the capability of infrared (IR) spectroscopy based machine learning tools [principal component analysis (PCA) and Random Forest (RF) classifier] for the rapid detection of ESBL+ bacteria isolated directly from patients' urine. For that, we examined 1881 E. coli samples (416 ESBL+ and 1465 ESBL-) and 609 K. pneumoniae samples (237 ESBL+ and 372 ESBL-). All samples were isolated directly from the urine of midstream patients. This study revealed that within 40 min of receiving the patient urine it is possible to determine the infecting bacterium as E. coli or K. pneumoniae with 95% success rate while it was possible to determine the ESBL+E. coli and ESBL+K. pneumoniae with 83% and 78% accuracy rates, respectively.

Comparison of FT-IR with whole-genome sequencing for identification of maternal-to­neonate transmission of antibiotic-resistant bacteria.

Following a previous study in which we evaluated the carriage rates of extended spectrum ß-lactamase (ESBL) -producing Enterobacterales (ESBL+ E), carbapenem-resistant Enterobacterales (CRE), vancomycin-resistant Enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA) among pregnant women and their neonates, in the current study we used, for the first time, Fourier transform infrared spectrometry (FT-IR) in order to determine whether antibiotic-resistant bacteria colonization in neonates has resulted from a vertical transmission from the mothers. To this end, 28 pairs of maternal and neonatal isolates of antibiotic-resistant bacteria, including ESBL-producing E. coli (ESBL+E.coli), ESBL-producing K. pneumoniae (ESBL+K. pneumoniae) and MRSA isolates, were subjected to a FT-IR analysis to assess the similarity between maternal and new-born isolates. We compared the FT-IR analysis results with whole genome sequencing of the isolates, in order to define whether FT-IR spectroscopy can be applied for bio-typing of bacteria and for assessment of mother-to­neonate transmission. The FT-IR analysis showed that all neonatal isolates were similar to their corresponding maternal isolates and belonged to the same cluster. Alignments of the DNA sequences of the maternal and neonatal isolates pairs revealed above 99% identity, thus confirming the FT-IR results. In conclusion, FT-IR spectroscopy can be applied to monitor bacterial transmission and specifically maternal-to­neonate transmission.

Trends and risk factors of extended-spectrum beta-lactamase urinary tract infection in Chinese children: a nomogram is built and urologist should act in time.

Background: To investigate the etiological characteristics and risk factors of extended-spectrum beta-lactamase (ESBL) urinary tract infection (UTI) and construct a corresponding nomogram to predict the probability of ESBL(+) UTI. Methods: We retrospectively reviewed the records among patients experiencing UTI events in Chongqing Medical University Affiliated Children's Hospital from 1994 and 2019. Results: A total of 854 patients with UTI were evaluated and ESBL-producing bacteria increased significantly. Significant potential risk factors of ESBL-UTI were congenital urological abnormalities, vesicoureteral reflux, neurologic disorder, age <12 months, fever and previous use of antibiotics. On logistic regression analysis, neurological disorder (OR =8, 95% CI: 1.845-34.695) and antibiotics administration in the last 3 months (OR =4.764, 95% CI: 3.114-7.289) were identified as an independent significant risk factor for ESBL-UTI. The nomogram generated was well calibrated for all predictions of ESBL+ probability, and the accuracy of the model nomogram measured by Harrell's C statistic (C-index) was 0.741. Conclusions: The current situation of multiple bacterial antibiotic resistance has become a worrisome issue in UTI and early identification of ESBL production is important in terms of appropriate treatment and effective infection control. We may choose broad-spectrum antibiotics as empirical antibiotics for UTI among children with neurological disease and used antibiotic in the last three months.

Spatiotemporal variation in urban wastewater pollution impacts on river microbiomes and associated hazards in the Akaki catchment, Addis Ababa, Ethiopia.

In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6-20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.

Occurrence, Antimicrobial Resistance Profile, and Characterization of Extended-Spectrum ß-Lactamase-Producing Escherichia coli Isolates from Minced Meat at Local Markets in Thailand.

Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli exhibits strong multidrug resistance (MDR) to ampicillin and third-generation cephalosporins. This study examined the occurrence, antimicrobial susceptibility, and molecular genetic features of ESBL-producing E. coli isolates from three commonly consumed minced meat varieties, namely pork, chicken, and beef. In total, 150 samples were collected from 10 local markets in Thailand. ESBL-producing E. coli was identified in 78 samples (52%), and minced chicken meat was most contaminated (79.17%). The isolates exhibited potential susceptibility to amikacin (96.16%) and carbapenems (91-95%). However, ESBL-producing E. coli displayed strong resistance to ampicillin and cefpodoxime (100%) and high MDR to 3-5 antibiotic classes (94.87%). Most presumptive ESBL producers harbored ESBL resistance genes (97.44%), most commonly blaTEM (78.21%). Indeed, our results demonstrated that raw minced meat has a high occurrence of ESBL-producing E. coli harboring ESBL resistance genes, highlighting the importance of implementation of sanitary handling practices to reduce microbial contamination in commercial meat as well as the need for consumer education on safe handling and cooking of meat products.

Predictors and outcomes of diabetic foot ulcer infection with ESBL-producing bacteria in a large tertiary center.

OBJECTIVES: The aim of this study was to describe the predictors and outcomes of infection with extended-spectrum beta-lactamase (ESBL)-producing bacteria in patients with an acute diabetic foot infection (DFI). METHODS: The records of patients admitted with acute DFI to a large tertiary hospital during the years 2014-2018 were reviewed. Demographic, clinical, and laboratory data were collected, as well as outcomes regarding amputations and mortality. Only cultures obtained during the first 2 weeks following admission were considered. RESULTS: Cultures were available for 493 patients; 121 (24.5%) included bacteria suspected of being ESBL producers. Patients infected with ESBL-producing bacteria were older, more likely to have peripheral vascular disease (PVD), and had higher SINBAD and Wagner scores upon admission. They were also more likely to have been hospitalized in the recent 6 months. Major amputations were more prevalent in patients with versus without an ESBL-producing bacterial infection (30.6% vs 19.4%; P = 0.010), yet overall amputations and mortality rates were similar. CONCLUSIONS: ESBL-producing bacteria are common pathogens in DFI, more prevalent in older patients with PVD, advanced ulcers, and recent hospitalization. They are associated with higher rates of major amputation. These considerations may support the choice of empirical antibiotic therapy in patients admitted with an acute DFI.

Prevalence and characterization of extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolated from raw vegetables retailed in Southern Thailand.

BACKGROUND: The increasing prevalence of broad-spectrum ampicillin-resistant and third-generation cephalosporin-resistant Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae, has become a global concern, with its clinical impacts on both human and veterinary medicine. This study examined the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum ß-lactamase (ESBL)-producing E. coli and K. pneumoniae isolates from 10 types of raw vegetables. METHODS: In total, 305 samples were collected from 9 markets in Nakhon Si Thammarat, Thailand, in 2020. RESULTS: ESBL-producing E. coli and K. pneumoniae isolates were found in 14 of the 305 samples obtained from 7 out of 10 types of vegetables (4.6% of the total). Further, 14 ESBL-producing E. coli (n = 5/14) and K. pneumoniae isolates (n = 9/14) (1.6% and 3.0%, respectively) were highly sensitive to ß-lactam/carbapenem antibiotics (imipenem, 100%). ESBL-producing E. coli (n = 4) and K. pneumoniae isolates (n = 8) were also sensitive to non-ß-lactam aminoglycosides (amikacin, 80.00% and 88.89%, respectively). ESBL producers were most resistant to ß-lactam antibiotics, including ampicillin (85.71%) and the cephalosporins cefotaxime and ceftazidime (64.29%). The most frequently detected gene in ESBL-producing E. coli and K. pneumoniae was blaSHV . However, two ESBL-producing E. coli isolates also carried three other ESBL-encoding variants, blaTEM , blaCTX-M1 , blaGES and blaTEM, blaSHV, blaCTX-M9 , which may be due to their association with food chains and humans. DISCUSSION: Indeed, our results suggest that raw vegetables are an important source of ESBL-resistant E. coli and K. pneumoniae, which are potentially transmittable to humans via raw vegetable intake.

Extended-Spectrum ß-Lactamase-Producing and mcr-1-Positive Escherichia coli from the Gut Microbiota of Healthy Singaporeans.

Multidrug-resistant (MDR) Escherichia coli strains that carry extended-spectrum ß-lactamases (ESBLs) or colistin resistance gene mcr-1 have been identified in the human gut at an increasing incidence worldwide. In this study, we isolated and characterized MDR Enterobacteriaceae from the gut microbiota of healthy Singaporeans and show that the detection rates for ESBL-producing and mcr-positive Enterobacteriaceae are 25.7% (28/109) and 7.3% (8/109), respectively. Whole-genome sequencing analysis of the 37 E. coli isolates assigned them into 25 sequence types and 6 different phylogroups, suggesting that the MDR E. coli gut colonizers are highly diverse. We then analyzed the genetic context of the resistance genes and found that composite transposons played important roles in the cotransfer of blaCTX-M-15/55 and qnrS1, as well as the acquisition of mcr-1. Furthermore, comparative genomic analysis showed that 12 of the 37 MDR E. coli isolates showed high similarity to ESBL-producing E. coli isolates from raw meat products in local markets. By analyzing the core genome single nucleotide polymorphisms (SNPs) shared by these isolates, we identified possible clonal transmission of an MDR E. coli clone between human and raw meat, as well as a group of highly similar IncI2 (Delta) plasmids that might be responsible for the dissemination of mcr-1 in a much wider geographic region. Together, these results suggest that antibiotic resistance may be transmitted between different environmental settings by the expansion of MDR E. coli clones, as well as by the dissemination of resistance plasmids. IMPORTANCE The human gut can harbor both antibiotic-resistant and virulent Escherichia coli which may subsequently cause infections. In this study, we found that multidrug-resistant (MDR) E. coli isolates from the gut of healthy Singaporeans carry a diverse range of antibiotic resistance mechanisms and virulence factor genes and are highly diverse. By comparing their genomes with the extended-spectrum ß-lactamase (ESBL)-producing E. coli isolates from raw meat products that were sampled at a similar time from local markets, we detected an MDR E. coli clone that was possibly transmitted between humans and raw meat products. Furthermore, we also found that a group of resistance plasmids might be responsible for the dissemination of colistin resistance gene mcr-1 in Singapore, Malaysia, and Europe. Our findings call for better countermeasures to block the transmission of antibiotic resistance.

The Washing Machine as a Reservoir for Transmission of Extended-Spectrum-Beta-Lactamase (CTX-M-15)-Producing Klebsiella oxytoca ST201 to Newborns.

During the period from April 2012 to May 2013, 13 newborns (1 to 4 weeks of age) and 1 child in a pediatric hospital ward in Germany were colonized with Klebsiella oxytoca producing an extended-spectrum beta-lactamase (ESBL) (CTX-M-15). A microbiological source-tracking analysis with human and environmental samples was carried out to identify the source and transmission pathways of the K. oxytoca clone. In addition, different hygienic intervention methods were evaluated. K. oxytoca isolates were detected in the detergent drawer and on the rubber door seal of a domestic washer-extractor machine that was used in the same ward to wash laundry for the newborns, as well as in two sinks. These strains were typed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. The environmental findings were compared with those for the human strains and the isolates detected on clothing. The results from both techniques showed that the strains were identical (sequence type 201 and PFGE type 00531, a clone specific to this hospital and not previously isolated in Germany), emphasizing the washing machine as a reservoir and fomite for the transmission of these multidrug-resistant bacteria. After the washing machine was taken out of use, no further colonizations were detected during the subsequent 4-year period.IMPORTANCE Washing machines should be further investigated as possible sites for horizontal gene transfer (ESBL genes) and cross-contamination with clinically important Gram-negative strains. Particularly in the health care sector, the knowledge of possible (re-)contamination of laundry (patients' clothes and staff uniforms) with multidrug-resistant Gram-negative bacteria could help to prevent and to control nosocomial infections. This report describes an outbreak with a single strain of a multidrug-resistant bacterium (Klebsiella oxytoca sequence type 201) in a neonatal intensive care unit that was terminated only when the washing machine was removed. In addition, the study implies that changes in washing machine design and processing are required to prevent accumulation of residual water where microbial growth can occur and contaminate clothes.

Graphene/nickel oxide nanocomposites against isolated ESBL producing bacteria and A549 cancer cells.

The synthesis of nickel oxide nanoparticles (NiO NPs) and graphene/nickel oxide nanocomposites (Gr/NiO NCs) was performed using a simple chemical reduction method. Powder X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to examine the crystalline nature and thermal stability of the synthesized NiO NPs and Gr/NiO NCs, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were utilized to observe the morphology of NiO NPs and Gr/NiO NCs and estimate their size range. TEM suggested that the NiO NPs were speared onto the surface of Gr nanosheet. The efficiency of NiO NPs and Gr/NiO NCs against extended spectrum ß-lacamase (ESBL) producing bacteria, which was confirmed by specific HEXA disc Hexa G-minus 24 (HX-096) and MIC strip methods (CLSI); namely Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) was investigated using the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods. MIC results suggested that the NiO NPs and Gr/NiO NCs possess maximum growth inhibition of 86%, 82% and 94%, 92% at 50 and 30 µg/mL concentrations, respectively. Similarly, both nanomaterials were found to inhibit the ß-lacamase enzyme at concentrations of 60 µg/mL and 40 µg/mL, respectively. The cytotoxicity of NiO NPs and Gr/NiO NCs was quantified against A549 human lung cancer cells. Cell death percentage values of 52% at 50 µg/mL against NiO NPs and 54% at 20 µg/mL against Gr/NiO NCs were obtained, respectively. The NCs were found to reduce cell viability, increase the level of reactive oxygen species (ROS) and modify both the mitochondrial membrane permeability and cell cycle arrest.

Zoonotic multidrug-resistant microorganisms among non-hospitalized horses from Germany.

Colonization with multidrug-resistant organisms (MDROs) belonging to the genus Staphylococcus and the order Enterobacterales poses a particular threat to populations at risk. While previous studies focused on MDRO carriage among livestock or companion animals, respective epidemiological data on the general equine population are limited. Here, carriage of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (ESBL-E) in non-hospitalized horses living on private farms in the rural area in Northwest Germany was assessed. Intranasal and perianal swab samples were cultured on solid chromogenic media directly and after enrichment in tryptic soy broth, respectively. S. aureus isolates were spa-typed, MRSA and ESBL-E were further classified by phenotypic and molecular methods. Additionally, a subgroup of the first 20 samples was used to isolate and characterize staphylococci other than S. aureus. Among 223 horses, fifteen (6.8%) carried S. aureus. Two isolates were identified as MRSA (0.9% of all horses, mecA-positive) and classified as spa types t011 and t6867, both known as members of the livestock-associated MRSA MLST clonal complex 398. Nine horses (4.0%) were colonized by ESBL-Escherichia coli positive for bla CTX-M and/or bla TEM. ESBL-E carriage was associated with prior antibiotic treatment (4/31 vs. 5/183; p = 0.0362) and veterinary examinations (4/31 vs. 5/183; p = 0.0362). In the subgroup, nine different staphylococcal species other than S. aureus were found. The high prevalence of ESBL-E. coli in non-hospitalized horses underlines the necessity to raise awareness for strain dissemination across different hosts in order to do justice to the "One Health" concept.

Formulation of Ceftriaxone Conjugated Gold Nanoparticles and Their Medical Applications against Extended-Spectrum ß-Lactamase Producing Bacteria and Breast Cancer.

Gold nanoparticles (AuNP) and their conjugates have been gaining a great deal of recognition in the medical field. Meanwhile, extended-spectrum ß-lactamases (ESBL)-producing bacteria are also demonstrating a challenging problem for health care. The aim of this study was the biosynthesis of AuNP using Rosa damascenes petal extract and conjugation of ceftriaxone antibiotic (Cef-AuNP) in inhibiting ESBL-producing bacteria and study of in vitro anticancer activity. Characterization of the synthesized AuNP and Cef-AuNP was studied. ESB-Lproducing strains, Acinetobacter baumannii ACI1 and Pseudomonas aeruginosa PSE4 were used for testing the efficacy of Cef-AuNP. The cells of MCF-7 breast cancer were treated with previous AuNP and Cef-AuNP at different time intervals. Cytotoxicity effects of apoptosis and its molecular mechanism were evaluated. Ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy established the formation of AuNP and Cef-AuNP. Transmission electron microscope demonstrated that the formed nanoparticles were of different shapes with sizes of 15~35 nm and conjugation was established by a slight increase in size. Minimum inhibitory concentration (MIC) values of Cef-AuNP against tested strains were obtained as 3.6 and 4 µg/ml, respectively. Cef-AuNP demonstrated a decrease in the MIC of ceftriaxone down to more than 27 folds on the studied strains. The biosynthesized AuNP displayed apoptotic and time-dependent cytotoxic effects in the cells of MCF-7 at a concentration of 0.1 µg/ml medium. The Cef-AuNP have low significant effects on MCF-7 cells. These results enhance the conjugating utility in old unresponsive ceftriaxone with AuNP to restore its efficiency against otherwise resistant bacterial pathogens. Additionally, AuNP may be used as an alternative chemotherapeutic treatment of MCF-7 cancer cells.

Isolation of ESBL-producing Bacteria from Sputum in Community-acquired Pneumonia or Healthcare-associated Pneumonia Does Not Indicate the Need for Antibiotics with Activity against This Class.

Objective In the past decade, extended-spectrum ß-lactamase (ESBL)-producing bacteria have increasingly frequently been isolated from various kinds of clinical specimens. However, the appropriate treatment of pneumonia in which ESBL-producing bacteria are isolated from sputum culture is poorly understood. To investigate whether or not ESBL-producing bacteria isolated from sputum in pneumonia cases should be treated as the causative bacteria. Methods and Patients In this retrospective study, we screened for patients, admitted between January 2009 and December 2015 in whom pneumonia was suspected and for whom sputum cultures yielded Escherichia coli or Klebsiella spp. isolates. We identified patients with community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP) from whom ESBL-producing bacteria had been isolated from sputum culture and to whom antibiotic treatment had been given with a diagnosis of pneumonia. We analyzed the patients' backgrounds and the effect of the antibiotic treatment for the initial 3-5 days. Results From 400 patients initially screened, 27 with ESBL-producing bacteria were secondarily screened. In this subset of patients, 15 were diagnosed with pneumonia, including 7 with CAP (5 E. coli and 2 K. pneumoniae) and 8 with HCAP (8 E. coli). These patients exhibited an average age of 84.1 years old, and 9 of 15 were men. No patients were initially treated with antimicrobials that are effective against isolated ESBL-producing bacteria. However, 13 of 15 patients showed improvement of pneumonia following the initial antibiotic treatment. Conclusion ESBL-producing bacteria isolated from sputum are not likely to be the actual causative organisms of pneumonia.

Study on microbial communities in domestic kitchen sponges: Evidence of Cronobacter sakazakii and Extended Spectrum Beta Lactamase (ESBL) producing bacteria.

Domestic environment, in particular, kitchen setting is a well-established source of microbial contamination. Kitchen sponges represent an important vehicle of microbial transmission and maintenance of spoilage bacteria and pathogenic strains responsible for food borne diseases. The aim of this study was to evaluate the microbial communities of 100 'in-use' kitchen sponges, improving the knowledge on their role in cross-contamination in domestic environment and transmission of ESBLproducing strains. Sponges were processed for: aerobic mesophilic bacteria (AMB), Enterobacteriaceae (EB), yeasts and molds (YM), coagulase-positive staphylococci (CPS), micrococci (MCC), anaerobic sulfite reducing bacteria (ASR), and for the detection of Listeria monocytogenes, Salmonella spp. and Yersinia enterocolitica. A total of 309 enterobacteria strains were identified and then processed for ESBL (Extended Spectrum Beta Lactamase) phenotypical expression. A high contamination level of kitchen sponges was observed (mean value AMB 8.25±1.1; EB 5.89±1.2; YM 5.57±1.1; MCC 4.82±0.1 log CFU/g). Identified enterobacteria strains revealed several opportunistic and pathogenic agents such as Enterobacter cloacae (28%), Citrobacter freundii (23.3%), Cronobacter sakazakii (14.6%) and other strains in lower percentage. Listeria monocytogenes was found in only one sponge (1%). A total of 69 (22.3%) enterobacteria resulted ESBL+, with the following prevalence: P. rettgeri (50%), L. adenocarboxilata (30%), K. pneumoniae (25%), K. oxytoca (25%), C. sakazakii (20%), E. cloacae (20.7%), C. freundii (20.1%). Results confirm the potential role of kitchen sponges as vehicle for food-borne pathogens such as, C. sakazakii for the first time, infectious agents and spoilage microorganisms. The observed high contamination level and the presence of several ESBLs opportunistic pathogens, stresses the necessity to improve a proper education of the consumers on the effective treatment to reduce their microbial loads.

Direct detection of mecA, blaSHV , blaCTX-M , blaTEM and blaOXA genes from positive blood culture bottles by multiplex-touchdown PCR assay.

Methicillin-resistant staphylococci (MRS) and ESBL(Extended-Spectrum ß-Lactamase)-producing bacteria are the most important resistant pathogens in sepsis. In this study, a new multiplex-touchdown PCR method (MT-PCR) was developed to detect rapidly and simultaneously the presence of mecA, blaSHV , blaCTX-M , blaTEM and blaOXA genes from positive blood culture bottles. The technique showed a sensitivity of 103  CFU ml-1 for mecA detection and of 102  CFU ml-1 for other genes, and 100% specificity in the detection of all genes. All genes were detected in the spiked blood culture bottles artificially contaminated with reference strains. Three methicillin-resistant S. aureus (MRSA), two methicillin-resistant S. epidermidis (MRSE) and 32 ESBL-producing bacteria, were isolated from the clinical blood culture specimens in 48 h by standard microbiological procedures. The corresponding genes were detected directly in the three MRSA, two MRSE and 29 ESBL-producing bacteria from the clinical blood culture specimens in 4 h by MT-PCR assay. None of the blaSHV , blaCTX-M , blaTEM and blaOXA genes were detected in three other bottles with ESBL-producing bacteria because of other ESBL genotypes in the pathogens. Likewise, all bottles proven negative by culture remained negative by PCR. The proposed method was rapid, sensitive and specific, and was able to directly detect the genes of MRS and ESBL-producing bacteria from the blood culture bottles. SIGNIFICANCE AND IMPACT OF THE STUDY: Many studies on the development of PCR for the detection of resistance genes have already been published, including multiplex PCR methods. However, cross-amplification reactions can be a major concern in multiplex PCR methods. In this study, we developed a highly sensitive and specific multiplex-touchdown PCR assay for simultaneous detection of mecA, blaSHV , blaCTX-M , blaTEM and blaOXA genes from positive blood culture bottles, cross-amplification was absent and false-positive results were not obtained.

Skin and soft-tissue infections: Factors associated with mortality and re-admissions.

INTRODUCTION: Skin and soft-tissue infections (SSTIs) are common and are linked to a wide variety of clinical conditions. Few studies have analysed the factors associated with mortality and re-admissions in medical patients with SSTIs. Accordingly, this study sought to describe the clinical and microbiological characteristics of patients diagnosed with SSTIs, and identify mortality and re-admission related factors. PATIENTS AND METHODS: A total of 308 patients were included in the study. Clinical, socio-demographic and microbiological characteristics were collected. Univariate and logistic regression multivariate analyses were performed in order to identify factors associated with mortality and re-admission. RESULTS: The bacteria responsible were identified in 95 (30.8%) patients, with gram-positive bacteria being isolated in 67.4% and gram-negative in 55.8% of cases. Multi-resistant bacteria were frequent (39%), and the initial empirical treatment proved inadequate in 25.3% of all cases. In-hospital mortality was 14.9%; the related variables were heart failure (OR=5.96; 95%CI: 1.93-18.47), chronic renal disease (OR=6.04; 95%CI: 1.80-20.22), necrotic infection (OR=4.33; 95%CI: 1.26-14.95), and inadequate empirical treatment (OR=44.74; 95%CI: 5.40-370.73). Six-month mortality was 8%, with the main related factors being chronic renal disease (OR: 3.03; 95%CI: 1.06-8.66), and a Barthel Index score of under 20 (OR: 3.62; 95%CI: 1.17-11.21). Re-admission was necessary in 26.3% of cases, with the readmission-related variables being male gender (OR: 2.12; 95%CI: 1.14-3.94), peripheral vascular disease (OR: 3.05; 95%CI: 1.25-7.41), and an age-adjusted Charlson Comorbidity Index score of over 3 (OR: 3.27; 95%CI: 1.40-7.63). CONCLUSIONS: Clinical variables such as heart failure, chronic renal disease, peripheral vascular disease, and necrotic infection could help identify high-risk patients. The main factor associated with higher mortality was inadequate initial empirical treatment. Physicians should consider gram-negative, and even extended-spectrum beta-lactamase-producing bacteria when assigning initial empirical treatment for SSTIs, especially in healthcare-associated cases.

Analysis of gene and drug resistance of ESBL producing bacteria in neonatal feces / 临床儿科杂志

Objectives To explore the route of ESBL producing bacteria in neonatal faeces, and to investigate the gene and drug resistance of ESBL producing bacteria in intestinal tract of neonates. Methods Fecal samples of healthy newborns and their mothers were collected, and bacterial cultures were carried out using selective ESBL medium. The positive strains were identified by Time-of-flight mass spectrometry. ESBL genotyping and resistance gene detection were performed by whole genome sequencing technique. Results In 146 neonatal fecal specimens, the positive rate of ESBL producing bacteria was 8.90％,and the positive rate in the first time stool was 3.23％. Seventy-two hours after birth, the positive rate of fecal ESBL producing bacteria was 13.10％. Among the 13 ESBL producing strains, there were 9 strains of CTX type, 3 strains of TEM type and 1 strain of SHV type. Nine strains of CTX include five types such as CTX-M-24, CTX-M-18, CTX-M-27, CTX-M-42 and CTX-M-15. The positive rate of ESBL producing bacteria was 21.6％ in 167 mothers' fecal specimens. The ESBL genotype included 24 strains of CTX type, 6 strains of TEM type, 4 strains of SHV type and 2 strains of QnrS type. Twenty-four strains of CTX include CTX-M-24, CTX-M-14, CTX-M-18, CTX-M-27, CTX-M-42 and CTX-M-15. There were 2 or 3 ESBL genotypes in 12 maternal and neonatal specimens. It was detected to have 6 types of resistance gene such as aadA5, strA, strB, sul1, sul2 and dfrA17 in 49 strains of ESBL producing bacteria in maternal and neonatal strains. Resistance genes were exactly the same in the neonates as in mothers who were detected to have ESBL producing bacteria. A variety of resistance genes were detected in feces in 7 neonates and 23 mothers. Conclusions The neonates in hospital may be detected to have ESBL produing bacteria in the intestinal tract at the same time as their mothers or separately. However, there are many ways for neonates to have ESBL producing bacteria in intestinal tract. There are many genotypes and resistance genes of ESBL producing bacteria.