Polymyxin E shows effective treatment of the infection induced by resistant gramnegative bacteria, but its nephrotoxicity severely limits the clinical application of this drug. In this work, methoxypolyethylene glycols 2000 (mPEG2K)-polymyxin E (PME) was synthesized via chemical grafting reaction and had been characterized. The antimicrobial activity and cytotoxicity of mPEG2K-PME in vitro were investigated on Escherichia coli and HK-2 cells, separately. Intra-abdominal infection model was further established in order to study the therapeutic effect and the toxic effect on kidney of mice. The results showed that mPEG2K-PME exhibited significant inhibitory effect on Escherichia coli and had a lower toxicity on HK-2 cells in vitro. At the same time, mPEG2K-PME had a good efficacy in the treatment of Escherichia coli infected mice in vivo. Moreover, nephrotoxicity caused by mPEG2K-PME was significantly reduced compared to free PME. mPEG2K-PME is promising in development of new preparations with high efficiency and low toxicity.
Animals ; Cell Line ; Colistin ; pharmacology ; toxicity ; Escherichia coli ; drug effects ; Escherichia coli Infections ; drug therapy ; Humans ; Kidney ; cytology ; drug effects ; Mice ; Polyethylene Glycols ; chemistry

Objective: To investigate the effect of hypochloric acid on Escherichia coli biofilm and the clinical efficacy of hypochloric acid for wounds with Escherichia coli infection. Methods: One strain of Escherichia coli with the strongest bacterial biofilm forming ability among the strains isolated from specimens in 25 patients (16 males and 9 females, aged 32-67 years) from five clinical departments of the 940^th Hospital of the Joint Logistic Support Force was collected for the experimental study from September to December 2019. The Escherichia coli was cultured with hypochloric acid at 162.96, 81.48, 40.74, 20.37, 10.18, 5.09, 2.55, 1.27, 0.64, and 0.32 μg/mL respectively to screen the minimum bactericidal concentration (MBC) of hypochloric acid. The Escherichia coli was cultured with hypochloric acid at the screened MBC for 2, 5, 10, 20, 30, and 60 min respectively to screen the shortest bactericidal time of hypochloric acid. The biofilm formation of Escherichia coli was observed by scanning electron microscopy at 6, 12, 24, 48, 72, and 96 h of incubation, respectively. After 72 h of culture, hypochloric acid at 1, 2, 4, 8, and 16 times of MBC was respectively added to Escherichia coli to screen the minimum biofilm eradicate concentration (MBEC) of hypochloric acid against Escherichia coli. After hypochloric acid at 1, 2, 4, and 8 times of MBEC and sterile saline were respectively added to Escherichia coli for 10 min, the live/dead bacterial staining kit was used to detect the number of live and dead cells, with the rate of dead bacteria calculated (the number of samples was 5). From January to December 2020, 41 patients with infectious wounds meeting the inclusion criteria and admitted to the Department of Burns and Plastic Surgery of the 940^th Hospital of Joint Logistic Support Force of PLA were included into the prospective randomized controlled trial. The patients were divided into hypochloric acid group with 21 patients (13 males and 8 females, aged (46±14) years) and povidone iodine group with 20 patients (14 males and 6 females, aged (45±19) years) according to the random number table. Patients in the 2 groups were respectively dressed with sterile gauze soaked with hypochloric acid of 100 μg/mL and povidone iodine solution of 50 mg/mL with the dressings changed daily. Before the first dressing change and on the 10^th day of dressing change, tissue was taken from the wound and margin of the wound for culturing bacteria by agar culture method and quantifying the number of bacteria. The amount of wound exudate and granulation tissue growth were observed visually and scored before the first dressing change and on the 3^rd, 7^th, and 10^th days of dressing change. Data were statistically analyzed with one-way analysis of variance, Dunnett-t test, independent sample t test, Mann-Whitney U test, Wilcoxon signed-rank test, chi-square test, or Fisher's exact probability test. Results: The MBC of hypochloric acid against Escherichia coli was 10.18 μg/mL, and the shortest bactericidal time of hypochloric acid with MBC against Escherichia coli was 2 min. Escherichia coli was in a completely free state after 6 and 12 h of culture and gradually aggregated and adhered with the extension of culture time, forming a mature biofilm at 72 h of culture. The MBEC of hypochloric acid against Escherichia coli was 20.36 μg/mL. The Escherichia coli mortality rates after incubation with hypochloric acid at 1, 2, 4, and 8 times of MBEC for 10 min were significantly higher than that after incubation with sterile saline (with t values of 6.11, 25.04, 28.90, and 40.74, respectively, P<0.01). The amount of bacteria in the wound tissue of patients in hypochloric acid group on the 10^th day of dressing change was 2.61 (2.20, 3.30)×10⁴ colony forming unit (CFU)/g, significantly less than 4.77 (2.18, 12.48)×10⁴ CFU/g in povidone iodine group (Z=2.06, P<0.05). The amounts of bacteria in the wound tissue of patients in hypochloric acid group and povidone iodine group on the 10^th day of dressing change were significantly less than 2.97 (2.90, 3.04)×10⁶ and 2.97 (1.90, 7.95)×10⁶ CFU/g before the first dressing change (with Z values of 4.02 and 3.92, respectively, P<0.01). The score of wound exudate amount of patients in hypochloric acid group on the 10^th day of dressing change was significantly lower than that in povidone iodine group (Z=2.07, P<0.05). Compared with those before the first dressing change, the scores of wound exudate amount of patients in hypochloric acid group on the 7^th and 10^th days of dressing change were significantly decreased (with Z values of -3.99 and -4.12, respectively, P<0.01), and the scores of wound exudate amount of patients in povidone iodine group on the 7^th and 10^th days of dressing change were significantly decreased (with Z values of -3.54 and -3.93, respectively, P<0.01). The score of wound granulation tissue growth of patients in hypochloric acid group on the 10^th day of dressing change was significantly higher than that in povidone iodine group (Z=2.02, P<0.05). Compared with those before the first dressing change, the scores of wound granulation tissue growth of patients in hypochloric acid group on the 7^th and 10^th days of dressing change were significantly increased (with Z values of -3.13 and -3.67, respectively, P<0.01), and the scores of wound granulation tissue growth of patients in povidone iodine group on the 7^th and 10^th days of dressing change were significantly increased (with Z values of -3.12 and -3.50, respectively, P<0.01). Conclusions: Hypochloric acid can kill Escherichia coli both in free and biofilm status. Hypochloric acid at a low concentration shows a rapid bactericidal effect on mature Escherichia coli biofilm, and the higher the concentration of hypochloric acid, the better the bactericidal effect. The hypochloric acid of 100 μg/mL is effective in reducing the bacterial load on wounds with Escherichia coli infection in patients, as evidenced by a reduction in wound exudate and indirect promotion of granulation tissue growth, which is more effective than povidone iodine, the traditional topical antimicrobial agent.
Adult ; Aged ; Biofilms ; Escherichia coli ; Escherichia coli Infections/drug therapy* ; Female ; Humans ; Male ; Middle Aged ; Prospective Studies ; Surgical Wound Infection ; Treatment Outcome

OBJECTIVETo study the genotype distribution of extended-spectrum beta-lactamases (ESBLs) in ESBLs-producing Escherichia coli (E. coli) isolates from posthepatitic cirrhosis' patients with bloodstream infection.

METHODSE. coli were isolated in bloodstream from patients with posthepatitic cirrhosis between January and December in 2011. The strains were identified by VITEK-II. The antibiol susceptibility tests were performed with K-B method. beta-lactamases genes were detected multi-PCR, PCR, sequence and blast.

RESULTSA total of 79 non-duplicate clinical isolates of E coli were consecutively collected from liver cirrhosis' patients with bloodstream infection. There were 20 isolates produced TEM-1 type beta-lactamases and 1 isolate produced SHV-1 typebeta-lactamases. 40 clinical isolates were detected to produce CTX-M type ESBLs, there were 20 CTX-M-1 group and 26 CTX-M-9 group, including 6 stains habouring both CTX-M-1 and CTX-M-9 group. Eight CTX-M genotypes were confirmed by sequencing of the PCR products, including CTX-M-3, CTX-M-14, CTX-M-15, CTX-M-24, CTX-M-28, CTX-M-31, CTX-M-65 and CTX-M-79.

CONCLUSIONCTX-M genotype ESBLs was the most popular extended-spectrum beta-lactamases in E. coli isolated from liver cirrhosis' patients with bloodstream infection. The CTX-M-14 is the dominant epidemic type.

Bacteremia ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; enzymology ; genetics ; isolation & purification ; Escherichia coli Infections ; microbiology ; Escherichia coli Proteins ; genetics ; Genotype ; Hospitalization ; statistics & numerical data ; Humans ; Liver Cirrhosis ; therapy ; Microbial Sensitivity Tests ; beta-Lactamases ; genetics ; metabolism

OBJECTIVETo study the preventive effect of herbal formulation on experimental murine urinary tract infection (UTI) induced by Dr Escherichia coli 11128.

METHODSE. coli 11128 carrying Dr fimbriae was isolated from patients with chronic pyelonephritis. The minimal inhibitory concentration (MIC) value of herbal solution for E. coli 11128 was determined for further studies. Forty C3H/HeJ mice were divided into the herb-treated group (n=20, given Chinese herbs by gavage at an average dose of 20 g/kg body weight daily 3 days before inoculation), and control group (n=20, given the same amount of distilled water by gavage). Three and 6 days after infection, bacteria were counted in the urine and the kidneys of the mice. Kidney histopathologic changes were evaluated. Neutrophils infiltration and accumulation were detected.

RESULTSThe MIC value of herbal solution was 0.1 g/mL for the E. coli 11128. In herb-treated mice, there was a significant reduction in bacterial counts in urine and colonization densities of kidneys. Microscopic studies revealed signs of inflammation in kidneys. In herb-treated mice, herbal administration resulted in significantly reduced neutrophilic infiltrates (P<0.05). The semi-quantitative scores for renal lesions were significantly lower (P<0.05).

CONCLUSIONProphylactic administration of herbal formulation potentiated the effect in partially preventing experimental murine ascending UTI.

Animals ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Escherichia coli ; drug effects ; Escherichia coli Infections ; drug therapy ; prevention & control ; Female ; Kidney ; drug effects ; pathology ; Mice, Inbred C3H ; Phytotherapy ; Urinary Tract Infections ; drug therapy ; microbiology ; prevention & control

The use of intrauterine devices (IUDs) have been widespread since the 1960s. In 2002, the World Health Organization estimated that approximately 160 million women worldwide use IUDs. However, IUDs are associated with short-term complications such as vaginal bleeding, pelvic discomfort, dyspareunia and pelvic infection. Herein, we report the case of a woman who had recurrent urinary tract infection (UTI) due to the use of an IUD, even after treatment. The patient developed four episodes of UTI within a seven-month period after IUD insertion. During each episode of UTI, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) was cultured from the patient’s midstream urine. The IUD was finally removed, and culture of the removed IUD was positive for ESBL-producing E. coli. An infected IUD as a source of recurrent UTI should be considered in women with IUD in situ who develop recurrent UTI even after treatment.
Adult ; Anti-Bacterial Agents ; therapeutic use ; Escherichia coli Infections ; drug therapy ; etiology ; Female ; Humans ; Intrauterine Devices ; adverse effects ; Microbial Sensitivity Tests ; Recurrence ; Treatment Outcome ; Urinary Tract Infections ; drug therapy ; etiology ; microbiology ; Uropathogenic Escherichia coli ; enzymology ; beta-Lactamases ; metabolism

OBJECTIVETo analyze risk factors, clinical features, outcomes and antibiotic resistance of Escherichia coli(E.coli) causing bloodstream infections in children.

METHODAll inpatients with E. coli positive blood culture in Beijing Children's Hospital from January 2012 to May 2014 were enrolled; 112 cases were included, 66 cases (58.9%) were male, and 46 cases(41.1%) were female. Age range was 2 days to 16 years. Among them, 43 cases (38.4%) were neonates, 19 cases (17.0%) aged from 1 month to 1 year, 14 cases (12.5%) were 1-3 years old, and 36 cases (32.1%) were over three years old. We analyzed the divisions to which the patients were admitted, source of infection, underlying diseases, clinical characteristics, antibiotic resistance, and treatment outcomes, etc.

RESULTForty-six cases (41.1%) were treated in division of hematology, 42 (37.5%) in neonatology, 9 (8.0%) in internal medicine, 8 (7.1%) in surgery, and 7 (6.3%) in pediatric intensive care unit. Sixty-five cases(58.0%) had underlying diseases. Fever was the most frequently presented symptom, as it was seen in 91 cases (81.3%); 52 cases(46.4%) had respiratory symptoms. Among these, 43 cases had pneumonia, 3 cases had respiratory failure, 3 cases were diagnosed as upper respiratory tract infection, 2 had pulmonary hemorrhage and 1 case had bronchitis. Twenty-six cases (23.2%)were diagnosed as severe sepsis and purulent meningitis separately, 14 cases(12.5%) had urinary tract infection. There were 73 (65.2%) strains inducing extended spectrum β-lactamases (ESBLs), of which 6 (8.2%) and 10 (13.7%) strains were resistant to amikacin and carbapenems respectively. Resistance rate against other antimicrobial agents varied from 64.6% to 100%.

OUTCOMES92 (82.1%) cases were cured or had improvement while 20 patients (17.9%) died or could not be cured at the end of treatment. Positive ESBLs (χ(2) = 6.609, P = 0.010), being complicated with severe sepsis (χ(2) = 40.253, P = 0.000) and requiring mechanical ventilation (χ(2) = 34.441, P = 0.000) indicate poor prognosis.

CONCLUSIONPatients with underlying diseases and newborns are susceptible to E. coli bloodstream infection. ESBLs infection, severe sepsis and mechanical ventilation indicate poor prognosis in E. coli blood stream infection. Clinicians may use carbapenems as empirical treatment for ESBLs infection. There may be carbapenem-resistant enterobacteriaceae strains infection if patients receiving treatment with carbapenems have no response.

Adolescent ; Bacteremia ; Carbapenems ; therapeutic use ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; Escherichia coli Infections ; blood ; drug therapy ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Meningitis, Bacterial ; Microbial Sensitivity Tests ; Pneumonia ; Urinary Tract Infections ; beta-Lactamases

OBJECTIVE: To investigate the phylogenetics and prevalence of bloodstream infections with ST131, the antimicrobial resistance profiles of the pathogens, and the clinical features. METHODS: Non-duplicate isolates were collected from 144 patients with bloodstream infections in our hospital between January and December, 2016.The phylogenetic groups of the isolates were analyzed using multiplex PCR, and O serotyping of ST131 strains was performed by allele-specific PCR.The clinical characteristics of the 144 patients were analyzed to define the differences in the clinical features between patients with ST131 infection and those with non-ST131 infection.Antibiotic susceptibility of the isolates was determined using the Vitek 2 compact system. RESULTS: The phylogenetic group analysis showed a domination by group B2 (41.0%[59/144]), followed by group F, group B1 and group E, which accounted for 16.7%(24/144), 13.9%(20/144), and 13.2% (19/144), respectively.Nine strains (6.3%) of were identified to be ST131 strains, among which 8 were O25b-B2-ST131 strains and 1 was O16-B2-ST131 strain.Of the 9 cases of ST131 infection, 7(77.8%) were found to occur in a nosocomial setting.The demographic characteristics and clinical features of the ST131-infected patients were similar to those of non-ST131-infected patients.ST131 strains were sensitive to piperacillin/tazobactam, imipenem, ertapenem, and amikacin, but showed high resistance rates to cefazolin, ceftriaxone, ciprofloxacin, levofloxacin, gentamicin, and trimethoprim/ sulfamethoxazole (all over 50%).The positivity rate of ESBLs in the ST131 strains was 77.8%, and the multidrug resistance rate reached 88.9%, which was higher than that of non-ST131 isolates, but the difference was not statistically significant. CONCLUSIONS The most common phylogenetic groups of isolates from patients with bloodstream infections are group B2 and F, and the positivity rate of ST131 is low.We for the first time detected O16-ST131 in patients with blood-borne infections in China.The clinical features of ST131-infected patients are similar to those of non-ST131-infected patients.The positivity rate of ESBLs and the multidrug resistance rate are high in ST131 strains, which may raise concerns in the future.
Anti-Bacterial Agents ; therapeutic use ; Bacteremia ; drug therapy ; epidemiology ; microbiology ; China ; Drug Resistance, Bacterial ; Escherichia coli ; classification ; drug effects ; genetics ; Escherichia coli Infections ; drug therapy ; epidemiology ; microbiology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Phylogeny ; Species Specificity

OBJECTIVETo study the characteristics of community-acquired urinary tract infections (CAUTIs) in children, analyze the risk factors and the susceptibility of antibiotics, thus to provide references to the diagnosis and medication of Pseudomonas aeruginosa (PA)-CAUTIs. Mothod Totally 22 cases of PA-CAUTIs were selected in one hospital from Jan, 2006 to Jan, 2012, their clinical information, laboratory results and radiological images were collected, and were compared with the CAUTIs cased by E. coli of those randomly selected over the same period.

RESULTIn those 22 cases with PA-CAUTIs, the mean value of protein level was (32.25 ± 13.81) mg/ml, 19 of them were hospitalized, 6 had urinary operation history, 7 of them had long-term usage of glucocorticoids or immunosuppressive agents, and 20 had underlying diseases. A total of 22 children with 26 PA-CAUTIs episodes were compared to E. coli-CAUTIs. Compared with E. coli-CAUTIs patients, children with PA-CAUTIs more often presented with a lower albumin (P = 0.017), a history of urinary operation(P = 0.03), more cases had a history of urinary operation (P = 0.03), a long-term usage of glucocorticoids or immunosuppressive medication (P = 0.044). Through multivariate logistic regression of variables that were significant in univariate analysis (with hospitalizations, long-term usage of glucocorticoids or immunosuppressive, albumin, underlying disease and urinary operation histories), and it turned out that underlying diseases (odds ratio 8.500, 95% CI 1.513 - 47.761, P = 0.037) and with urinary operation histories (odds ratio 6.196, 95% CI 1.120 - 34.273, P = 0.037) were proved as the independent risk factors for PA-CAUTIs. Those PA bacterial strains had a 36.36% resistance rate to piperacillin, aztreonam and gentamicin, a 31.82% resistance rate to cefepime and ceftazidime, while the resistance rate (4.55%) to carbapenem antibiotics was relatively low, only to bacillosporin all the strains were sensitive.

CONCLUSIONUnderlying diseases and the urinary operation histories are the independent risk factors of the occurrence of PA-CAUTIs, carbapenem antibiotics and bacillosporin can be considered as the drugs of choice for its treatment.

Anti-Bacterial Agents ; therapeutic use ; Case-Control Studies ; Child ; Child, Preschool ; Community-Acquired Infections ; drug therapy ; epidemiology ; pathology ; Drug Resistance, Bacterial ; Escherichia coli ; drug effects ; Escherichia coli Infections ; drug therapy ; epidemiology ; pathology ; Female ; Humans ; Male ; Polymyxins ; therapeutic use ; Pseudomonas Infections ; drug therapy ; epidemiology ; pathology ; Pseudomonas aeruginosa ; drug effects ; Risk Factors ; Urinary Tract Infections ; drug therapy ; epidemiology ; pathology

Humans ; Escherichia coli ; Klebsiella pneumoniae ; Retrospective Studies ; Hospitals, General ; Singapore/epidemiology* ; Escherichia coli Infections/epidemiology* ; Sepsis/drug therapy* ; beta-Lactamases ; Anti-Bacterial Agents/therapeutic use* ; Bacteremia/drug therapy* ; Microbial Sensitivity Tests

This study aimed to provide evidence of persistent uropathogenic Escherichia coli (UPEC) in female patients with recurrent urinary tract infection (UTI) after antibiotic therapy. We collected biopsies of the bladder, and clean-catch urine samples from 32 women who had episodes of recurrent UTI and were given antibiotic therapy. Urine samples and biopsies were analyzed by conventional bacteriological techniques. Phylogenetic group and 16 virulence factors (VFs) of UPEC were determined using polymerase chain reaction (PCR). The infection capability of UPEC was confirmed in a mouse model. Immunofluorescence and electron microscopy were used to detect intracellular bacterial communities (IBCs) in the mouse model. The results showed that all urine specimens were detected sterile. E. coli was found in 6 of 32 biopsies (18.75%), and was identified to be UPEC by PCR. Different VFs associated with the formation of IBCs were identified in all six UPEC isolates. Each UPEC isolate was capable of forming IBCs within the bladder epithelial cells of mice. In conclusion, UPEC with distinctive pathological traits and the capability of IBC formation was first found in the bladders of women after antibiotic therapy, suggesting that the IBC pathogenic pathway may occur in humans and it plays an important role in UTI recurrence.
Adult ; Animals ; Anti-Bacterial Agents ; administration & dosage ; Biopsy ; Escherichia coli Infections ; drug therapy ; microbiology ; Female ; Humans ; Mice ; Middle Aged ; Phylogeny ; Urinary Bladder ; drug effects ; microbiology ; pathology ; Uropathogenic Escherichia coli ; drug effects ; genetics ; pathogenicity