Pharmacokinetics/Pharmacodynamics Evaluation of Flomoxef against Extended-Spectrum Beta-Lactamase-Producing Escherichia coli In Vitro and In Vivo in a Murine Thigh Infection Model.

PURPOSE: Although flomoxef (FMOX) has attracted substantial attention as an antibiotic against extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-producing E. coli), the pharmacokinetics/pharmacodynamics (PK/PD) characteristics of FMOX against ESBL-producing E. coli is unclear. The aim of this study was to determine the PK/PD index of FMOX against ESBL-producing E. coli. METHODS: In vitro time-kill curve studies and in vivo PK/PD experiments were carried out. RESULTS: Time-kill curves exhibited a unique bactericidal activity: time-dependent activity at low concentrations and concentration-dependent activity at high concentrations. In neutropenic murine thigh infection experiments, the antibacterial activity of FMOX correlated with the time that the free drug concentration remaining above the minimum inhibitory concentration (MIC) (fT>MIC) and the ratio of the area under the free drug concentration-time curve for a 24 h period to the MIC (fAUC24/MIC). However, the burden of ESBL producing E. coli significantly reduced when the time intervals for administration were shorter among three dosage regimens with same magnitude of fAUC24/MIC, indicating that fT>MIC is significant PK/PD index. The target value of fT>MIC for 1 log10 kill reduction was 35.1%. CONCLUSIONS: fT>MIC is the most significant PK/PD index of FMOX against ESBL-producing E. coli and its target value is ≥ 40%.

Efficacy of cefoxitin versus carbapenem in febrile male urinary tract infections caused by extended spectrum beta-lactamase-producing Escherichia coli: a multicenter retrospective cohort study with propensity score analysis.

Cefoxitin has demonstrated good in vitro activity against extended spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-Ec) and is regarded as a carbapenem-sparing beta-lactam alternative in urinary tract infections. Its efficacy has never been compared to carbapenems in male UTIs. Our study aimed to compare the clinical and microbiological efficacy of cefoxitin (FOX) and carbapenems (CP) in febrile M-UTI due to ESBL-Ec (F-M-UTI). We conducted a multicenter retrospective cohort study of patients with F-M-UTI treated with FOX or CP as definitive therapy, between January 2013 and June 2015, in six French acute care teaching hospitals. The clinical and microbiological efficacies of FOX and CP were compared using multivariable logistic regression models, adjusting for propensity scores. Of the 66 patients included, 23 patients in FOX group and 27 in CP group had clinical assessment at follow-up. Median follow-up after end of treatment was 63 days (interquartile range 26-114). Clinical success was observed for 17/23 (73.9%) and 22/27 (81.5%) patients and microbiological success for 11/19 (57.9%) and for 6/12 (50.0%) patients in FOX and CP groups respectively. We did not find any significant difference for clinical (OR = 0.90, 95% CI [0.12; 6.70]) neither microbiological (OR = 0.85, 95% CI [0.05; 14.00]) success between CP and FOX groups in univariate and multivariable models. In the FOX group, high dose with use of continuous infusion was associated with clinical success. These results add evidence that FOX is an effective alternative treatment to carbapenems for M-UTI caused by ESBL-Ec, particularly when high doses and continuous infusion are used.

Increased community-acquired upper urinary tract infections caused by extended-spectrum beta-lactamase-producing Escherichia coli in children and the efficacy of flomoxef and cefmetazole.

BACKGROUND: Urinary tract infections caused by extended-spectrum beta-lactamase-producing bacteria are increasing worldwide. At our hospital, the number of pediatric patients hospitalized because of an upper urinary tract infection has dramatically increased since 2016. In total, 60.5% of urinary tract infections are caused by extended-spectrum beta-lactamase-producing Escherichia coli. Such a high prevalence of extended-spectrum beta-lactamase-producing E. coli has not been detected previously in Japan. Therefore, we evaluated the clinical and bacteriologic characteristics and efficacy of antibiotics against upper urinary tract infections caused by E. coli in children. METHODS: This retrospective study surveyed 152 patients who were hospitalized in the pediatric department of Shimane Prefectural Central Hospital because of upper urinary tract infections caused by E. coli. Medical records were reviewed to examine patient characteristics. O antigens, antibiotic susceptibility, gene typing, and pulse-field gel electrophoresis were studied at the Shimane Prefectural Institute of Public Health and Environmental Science. RESULTS: Urine sample analyses showed extended-spectrum beta-lactamase types such as CTX-M-9 and plural virulence genes. We changed the primary antibiotic treatment to flomoxef or cefmetazole to treat upper urinary tract infections caused by Gram-negative bacilli. After changing treatment, the time to fever alleviation was significantly shortened. CONCLUSION: Extended-spectrum beta-lactamase-producing E. coli should be suspected in community-acquired upper urinary tract infections. Therefore, when treating patients, it is necessary to focus on antibiotic susceptibility and the prevalence of extended-spectrum beta-lactamase-producing bacteria found in each area. Flomoxef and cefmetazole are useful primary treatments for upper urinary tract infections caused by extended-spectrum beta-lactamase-producing E. coli.

Application of bacteriophages in simultaneously controlling Escherichia coli O157:H7 and extended-spectrum beta-lactamase producing Escherichia coli.

Shiga toxin-producing Escherichia coli (STEC) O157:H7 and extended-spectrum beta-lactamase (ESBL) producing E. coli (ESBLEC) are important bacteria of public health concern and frequently isolated from raw beef products. Bacteriophage-based methods have been increasingly exploited to control bacterial contamination in meats. Here, we describe the isolation, characterization, and application of a lytic phage PE37 for the simultaneous bio-control of STEC O157:H7 and ESBLEC. Phage PE37, isolated from the bovine intestine, was morphologically characterized as a member of the Myoviridae family, with a broad host range and great stability under various stress conditions. Sequencing analysis revealed that the genomic DNA of phage PE37 contains genes that contribute to virion structure, replication, assembly, and host lysis. PE37 significantly reduced the viable counts of STEC O157:H7 by 4.9 and 2.6 log CFU/mL in broth after 6 h of incubation at 25 and 8 °C, respectively. Application of phage PE37 to raw beef artificially contaminated with STEC O157:H7 resulted in significant reductions in the viable counts by 2.3 and 0.9 log CFU/piece after 24 h of storage at 25 and 8 °C, respectively. Treatment of raw beef contaminated with a bacterial cocktail of STEC O157:H7 and ESBLEC with PE37 also significantly decreased the viable counts of the bacterial mixture by 1.4 and 1.0 log CFU/piece after 24 h of incubation at 25 and 8 °C, respectively. These findings suggest that bacteriophage PE37 may be a potential bio-agent for controlling STEC O157:H7 and ESBLEC contamination in raw beef.

Comparison of rates of fecal colonization with extended-spectrum beta-lactamase-producing enterobacteria among patients in different wards, outpatients and medical students.

Because asymptomatic carriage of extended-spectrum beta-lactamase (ESBL) producers is a risk factor for infection, data on colonization dynamics are important when planning infection control. This study investigated fecal colonization with ESBL producers among inpatients, outpatients and medical students and compares the characteristics of ESBL producers among these groups. Carriage rates were investigated in 5581 fecal samples; 4343 from inpatients (330, 1397, 619 and 1864 from adult ICUs [intensive care units], adult non-ICUs, pediatric ICUs and pediatric non-ICUs, respectively), 814 from outpatients and 424 from screening of medical students. ESBL producers were characterized by co-resistance, integrons carried, and aminoglycoside resistance and ESBL genes. Dynamic regression models were built to identify relationships between combinations of time series of monthly antibiotic consumption, prevalence of carriers and infected subjects. Inpatients, ICU patients and adults showed higher prevalence than outpatients, non-ICU patients or children (7.4%, 9.3% and 12.0% vs. 3.1%, 6.1% and 4.1%, respectively). Klebsiella pneumoniae was more frequent in ICU patients; dominance of CTX-M-15 producers was more marked in adult than in pediatric inpatients. ESBL carriage was shown to be a consequence of infection in adults in the time-series analysis; antibiotic consumption had little effect. The epidemiology of colonization with ESBL producers differed between pediatric ICU, adult ICU and adult non-ICU patients. In adults, carriage of ESBL producers seems to be the consequence of infection, especially in ICU patients; the main source of colonization is nosocomial acquisition. In contrast, children are less likely to acquire colonizer strains in hospitals; importation of ESBL producers by colonized children seems to be significant.

Ulnar infected pseudoaneurysm in the course of extended-spectrum beta-lactamase Escherichia coli septicemia.

We describe the first case of proximal ulnar pseudoaneurysm due to extended-spectrum beta-lactamase-producing Escherichia coli. We performed an open ligation of the ulnar artery and partial excision of the aneurysmal sac. This article discusses the etiology and surgical management of ulnar-infected pseudoaneurysms according to the literature data.

Beta-Lactamase-Producing Escherichia coli Isolates Recovered from Pig Handlers in Retail Shops and Abattoirs in Selected Localities in Southern Nigeria: Implications for Public Health.

Antibiotic resistance evolution among pathogenic microorganisms has become a huge burden globally as it has increased the burden of diseases amongst humans and animals. The prevalence of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-Ec) and metallo beta-lactamase-producing Escherichia coli (MBL-Ec) isolated from pig abattoir and handlers in retail shops was studied. In addition, the relationship between the isolates' prevalence and the background characteristics of the butchers/retailers was also investigated. Samples from 32 hand swabs of pork sellers at retail shops and 8 butchers at abattoirs, as well as 272 swabs taken from knives, tables, floors, water troughs, and carcasses from both retail shops and abattoirs, were collected. Escherichia coli (E. coli) was isolated from hand swabs, fomites, and carcasses and were identified by standard microbiological procedures. The isolates susceptibility to nitrofurantoin (300 µg), ciprofloxacin (5 µg), ceftazidime (30 µg), cefuroxime (30 µg), gentamicin (10 µg), cefixime (5 µg), ofloxacin (5 µg), amoxicillin/clavulanic acid (30 µg), imipenem (10 µg), and meropenem (10 µg) and their ability to produce ESBL and MBL was determined by phenotypic methods. Demographic information of the handlers was retrieved by means of a structured questionnaire and, in some cases, via face to face interviews. Out of 104 E. coli isolates from both sources, 52 (50.0%) and 8 (7.7%) were ESBL and MBL producers, respectively. ESBL was more prevalent on the hands of the retailers (40.6%) and butchers (75.0%). The isolates were 100% resistant to ceftazidime, cefotaxime, and amoxicillin-clavulanic acid and 4.8% resistant to nitrofurantoin. Diverse resistance patterns were observed among ESBL-Ec and MBL-Ec. It was found that 90% of ESBL-Ec and 100% of MBL-Ec were multidrug-resistant. A possible epidemiological link between the two sources was observed. The prevalence of E. coli ESBL- and MBL-producing isolates was associated with the duty performed by handlers (p = 0.012) and gender (p = 0.012). Our results provide evidence that the handlers' hands and abattoir environment had a great role to play in the high prevalence and resistance profiles of the microorganisms.

Temporal trends and risk factors for extended-spectrum beta-lactamase-producing Escherichia coli in adults with catheter-associated urinary tract infections.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli cause up to 10% of catheter-associated urinary tract infections (CAUTI). We report changes in ESBL prevalence among CAUTIs in an adult acute care hospital from 2006-2012 and describe factors associated ESBL-production among E. coli CAUTI. FINDINGS: Data on patients ≥18 years discharged from a 647-bed tertiary/quaternary care hospital (2006-2012), a 221-bed community hospital (2007-2012), and a 914-bed tertiary/quaternary care hospital (2008) were obtained retrospectively from an electronic database (N = 415,430 discharges). Infections were identified using a previously validated electronic algorithm. Information on medical conditions and treatments were collected from electronic health records and discharge billing codes. A case-control design was used to determine factors associated with having a CAUTI caused by an ESBL-producing E. coli versus a non-ESBL-producing E. coli. Changes in yearly proportion of ESBL E. coli CAUTI at the 647-bed tertiary/quaternary care hospital were evaluated. ESBL increased from 4% in 2006 to 14% in 2012, peaking at 18% in 2009. Prior antibiotic treatment and urinary tract disease significantly increased odds of ESBL. CONCLUSIONS: This study provides evidence that treatment with beta-lactam and non-beta-lactam antibiotics is a risk factor for acquiring ESBL-producing E. coli CAUTI, and the prevalence of this organism may be increasing in acute care hospitals.