Emergence of extensive drug resistance and high prevalence of multidrug resistance among clinical Proteus mirabilis isolates in Egypt.

BACKGROUND: Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms. METHODS: Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated. RESULTS: Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where blaTEM, blaSHV, blaCTX-M, blaCIT-M and blaAmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where blaOXA-48 and blaNDM-1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-blaOXA-10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2). CONCLUSION: P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains.

Association of Proteus mirabilis and Providencia stuartii Infections with Diabetes.

Background and Objectives: Proteus and Providencia are related genera of opportunistic pathogens belonging to the Morganellaceae family, often a cause of infections in the immunocompromised hosts, such as diabetic patients. Their clinical significance has increased due to their intrinsic resistance to polymyxins, which is often associated with acquired resistance mechanisms. In this study we evaluated the infections caused by Proteus mirabilis and Providencia stuartii in two groups of patients, with diabetes (group 1) and without diabetes (group 2) admitted to the intensive care unit and surgical wards. The infections were investigated in terms of infection type, risk factors, clinical course, predictive factors for unfavourable outcomes and antibiotic resistance profile. Materials and Methods: An observational, retrospective, cross-sectional study was conducted, comprising all patients infected with these pathogens. Bacterial identification and antibiotic sensitivity testing were performed using the Vitek2C automated system. Results: Comparison of the two groups showed that the statistically significant common infectious risk factors were found less frequently among diabetic patients when compared with non-diabetic patients, and that antimicrobial resistance was significantly lower in the diabetic patient group. However, survival rates did not differ between the two groups, drawing attention to the implications of diabetes as comorbidity. Additionally, with regard to the antibiotic resistance profile, 38.89% of P. stuartii strains isolated from diabetic patients belonged to the difficult-to-treat (DTR) phenotype, contributing to the severity of these infections compared with those caused by P. mirabilis, of which 32% were wild type strains and 0% were DTR phenotype. The DTR/extended spectrum beta-lactamase producing P. stuartii isolates more than doubled the risk of mortality, while the presence of nasogastric nutrition tripled the risk. Conclusions: P. stuartii infections that occurred in diabetic patients proved to be more difficult to treat, the majority of them being healthcare-associated bacteremias.

Virulence, resistance and clonality of Proteus mirabilis isolated from patients with community-acquired urinary tract infection (CA-UTI) in Brazil.

Urinary tract infections (UTIs) are among the most common human infections, both in hospitals and in communities. Proteus mirabilis is known to cause community-acquired urinary tract infection (CA-UTI) and is an important causative agent of nosocomial UTIs. The pathogenesis of this species is related to its ability to manifest virulence factors, such as biofilms, adhesion molecules, urease, proteases, siderophores, and toxins. In this study, we investigated the virulence, sensitivity to antimicrobials, and clonal relationship of 183 strains isolated from the urine of CA-UTI patients in Londrina, Paraná State, Brazil. A total of 100% of the strains were positive for hpmA, ptA, zapA, mrpA, pmfA, ireA, and atfA virulence genes. The ucaA gene was positive in 81.4% of the cases. The strains showed high rates of sensitivity to the evaluated antimicrobials, and only one was ESBL-positive. All the tested bacteria showed the capacity to form biofilms: 73.2% had a very strong intensity, while 25.7% had a strong intensity, and 1.1% had a moderate intensity. Regarding clonality, 40 clonal clusters were found among the microorganisms tested. Our results showed that strains of P. mirabilis isolated from CA-UTI patients have several virulence factors. Although the urinary clinical isolates studied showed high sensitivity to antimicrobials, the strains showed a strong capacity to form biofilms, making antibiotic therapy difficult. In addition, it was observed that there were clones of P. mirabilis circulating in the city of Londrina.

Carbapenem-Susceptible OXA-23-Producing Proteus mirabilis in the French Community.

Nineteen Proteus mirabilis isolates producing the carbapenemase OXA-23 were recovered over a 2-year period in 19 French hospitalized patients, of whom 12 had community onset infections. The isolates exhibited a slightly reduced susceptibility to carbapenems. Whole-genome analysis revealed that all 19 isolates formed a cluster compared to 149 other P. mirabilis isolates. Because of its susceptibility to carbapenems, this clone may be misidentified as a penicillinase producer while it constitutes a reservoir of the OXA-23-encoding gene in the community.

Determination of epidemiology and antimicrobial susceptibility of extended spectrum beta lactamase producing uropathogens.

OBJECTIVE: To find the most suitable antibiotic against urinary tract infection caused by Extended Spectrum Beta Lactamase producing uropathogens, and the epidemiology of Extended Spectrum Beta Lactamase producers. METHODS: The cross-sectional study was conducted at Pir Mehr Ali Shah University of Arid Agriculture, Rawalpindi, Pakistan, from July 2014 to July 2015, and comprised urine samples of patients suffering from urinary tract infection which were cultured on Cysteine Lactose Electrolyte Deficient agar medium. Analysis was done on Muller- Hintonagar plates and optical density was set as 0.1 at 530nm. Antimicrobial sensitivity was tested using Kirby-Bauer disc diffusion method. Further confirmation was done through gram staining and biochemical tests. Extended Spectrum Beta Lactamase production was confirmed through phenotypic methods, including phenotypic confirmatory disc diffusion test, double disc synergy test and Epsilometer test. RESULTS: Of the 150 samples, 98(65%) showed growth of a total of 114 pathogenic isolates. Escherichia coli was the commonest organism in 94(82%) samples. Piperacillin Tazocin was the most suitable antimicrobial drug in 88(90%) cases. Overall, 23(20%) isolates were producers of Extended Spectrum Beta Lactamase. CONCLUSION: Piperacillin Tazocin was found to be the drug of choice for patient suffering from urinary tract infection.

Community onset of CTX-M extended spectrum ß-lactamases among uropathogenic E. coli and K. pneumoniae from Karachi, Pakistan.

Urinary tract infections (UTIs) are major health issue in developing countries like Pakistan, become more complicated with extended spectrum ß-lactamase (ESBL) expression in Escherichia coli and Klebsiella pneumoniae. The ground of this present study was to evaluate the incidence of cefotaxime (CTX-M) gene in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. The clinical isolates from various specimens were collected for one-year duration from January till December 2015. After initial screening (n=352) isolates were examined for phenotypic expression of ESBLs by double disc synergy test. Furthermore, eight-four isolates were analyzed by polymerase chain reaction for identification of Cefotaxime (CTX-M), Temoneira (TEM) and Sulfhdryl variable (SHV) genes. Among eighty-four clinical isolates CTX-M was dominant and found positive in 50 isolates (59.5%) followed by TEM in 35 (41.6%) and SHV in 11 (13%). In uropathogenic E. coli and K. pneumoniae, ESBLs gene was found in 50 and 6 isolates out of 57 and 7 respectively. Among uropathogens CTX-M was most prevalent 78% (39/50) in E. coli followed by K. pneumoniae. In uropathogenic E. coli, CTX-M was found dominant in females. The study concluded that ESBL related uropathogenic E. coli were CTX-M dominant, showed community onsets of UTIs that can be preventive and controlled with modified hygienic practices.

Dissemination of Multidrug-Resistant Proteus mirabilis Clones Carrying a Novel Integron-Borne blaIMP-1 in a Tertiary Hospital.

This study aimed to characterize multidrug-resistant Proteus mirabilis clones carrying a novel class 1 integron-borne blaIMP-1 In1359 was inserted into a large conjugative plasmid that also carried blaCTX-M-2 The production of carbapenemases in Enterobacteriaceae that are intrinsically resistant to polymyxins and tigecycline is very worrisome, representing a serious challenge to clinicians and infection control teams.

Primary and Secondary Bacteremia Caused by Proteus spp.: Epidemiology, Strains Susceptibility and Biofilm Formation.

Proteus spp. is an etiological factor of urinary tract and bloodstream infections. The aim of this study was the retrospective analysis of susceptibility of Proteus spp. strains isolated from bloodstream infections (BSIs) as well as similarity evaluation of the strains isolated from different clinical samples. Proteus spp. strains were isolated in 2009-2017 from hospital patients. Identification was based on the colony's morphology and biochemical or MALDI-TOF MS analyzes. The antibiotic susceptibility test was done using the diffusion method. Biofilm formation was evaluated with microplate method using TTC. Bacteremia caused by Proteus spp. was found in 97 patients, mainly secondary to urinary tract infection. Most of the strains were susceptible to piperacillin with tazobactam (95.9%) and amikacin (86.7%). Elderly patients have a higher risk of mortality after BSIs caused by Proteus spp. A detailed analysis was made for randomly chosen 26 strains isolated from 11 patients with Proteus mirabilis bacteremia. Using PFGE, we found that 10 (90.9%) isolates, collected from different clinical specimens of the same patient, were genetically identical.Proteus spp. is an etiological factor of urinary tract and bloodstream infections. The aim of this study was the retrospective analysis of susceptibility of Proteus spp. strains isolated from bloodstream infections (BSIs) as well as similarity evaluation of the strains isolated from different clinical samples. Proteus spp. strains were isolated in 2009­2017 from hospital patients. Identification was based on the colony's morphology and biochemical or MALDI-TOF MS analyzes. The antibiotic susceptibility test was done using the diffusion method. Biofilm formation was evaluated with microplate method using TTC. Bacteremia caused by Proteus spp. was found in 97 patients, mainly secondary to urinary tract infection. Most of the strains were susceptible to piperacillin with tazobactam (95.9%) and amikacin (86.7%). Elderly patients have a higher risk of mortality after BSIs caused by Proteus spp. A detailed analysis was made for randomly chosen 26 strains isolated from 11 patients with Proteus mirabilis bacteremia. Using PFGE, we found that 10 (90.9%) isolates, collected from different clinical specimens of the same patient, were genetically identical.

Evolving beta-lactamase epidemiology in Enterobacteriaceae from Italian nationwide surveillance, October 2013: KPC-carbapenemase spreading among outpatients.

Extended-spectrum beta-lactamases (ESBLs), AmpC-type beta-lactamases (ACBLs) and carbapenemases are among the most important resistance mechanisms in Enterobacteriaceae. This study investigated the presence of these resistance mechanisms in consecutive non-replicate isolates of Escherichia coli (n = 2,352), Klebsiella pneumoniae (n = 697), and Proteus mirabilis (n = 275) from an Italian nationwide cross-sectional survey carried out in October 2013. Overall, 15.3% of isolates were non-susceptible to extended-spectrum cephalosporins but susceptible to carbapenems (ESCR-carbaS), while 4.3% were also non-susceptible to carbapenems (ESCR-carbaR). ESCR-carbaS isolates were contributed by all three species, with higher proportions among isolates from inpatients (20.3%) but remarkable proportions also among those from outpatients (11.1%). Most ESCR-carbaS isolates were ESBL-positive (90.5%), and most of them were contributed by E. coli carrying blaCTX-M group 1 genes. Acquired ACBLs were less common and mostly detected in P. mirabilis. ESCR-carbaR isolates were mostly contributed by K. pneumoniae (25.1% and 7.7% among K. pneumoniae isolates from inpatients and outpatients, respectively), with blaKPC as the most common carbapenemase gene. Results showed an increasing trend for both ESBL and carbapenemase producers in comparison with previous Italian surveys, also among outpatients.

Molecular Epidemiology and Genetic Characteristics of Various blaPER Genes in Shanghai, China.

We describe the genetic characteristics and possible transmission mechanism of blaPER in 25 clinical Gram-negative bacilli in Shanghai. blaPER, including blaPER-1, blaPER-3, and blaPER-4, was located chromosomally or in different plasmids. Tn1213 harboring blaPER-1 was first identified in two Proteus mirabilis isolates in China. The other blaPER variants were preceded by an ISCR1 element inside the complex class 1 integron associated with IS26, Tn21, Tn1696, and a miniature inverted-repeat transposable element.

Microbiological profile of chronic suppurative otits media among HIV infected children in South Eastern Nigeria.

Background: Immune compromised HIV/AIDS infected children have consistently shown a higher prevalence of chronic suppurative otitis media than their immune competent counterparts.This study aimed to compare the microbial isolates from ear discharges in HIV infected and non infected children. Method: This was a Hospital based prospective cohort study designed to determine the relative prevalence of the common organisms present in chronically discharging ears of HIV infected children and their antimicrobial sensitivities and compare that of age and sex matched non HIV infected children. Fifty HIV infected children being followed up at the paediatric HIV clinic of a tertiary health facility, had ear swabs obtained for culture and antimicrobial sensitivity.The same was done for another cohort of fifty age and sex matched non HIV infected children. Results: The mean age of the study population and controls were 6years 11months (SD 0.96) and 7years 11 months (SD 1.00) respectively. Male to female ratio for each group was 1:1.Ear discharge was bilateral in 27(54%) HIV infected children and in 35(70%) of the controls. The most prevalent bacterial isolate in both groups was Pseudomonas aeruginosa though it was more prevalent in HIV infected children(P=0.005). Fungal isolates were commoner in non HIV infected children(P=0.001).Ninety percent sensitivity to the 4 Quinolones was recorded by isolates in HIV infected children while sensitivity to the Aminoglycosides was greater in non HIV infected children Conclusion: Pseudomonas aeruginosa is the predominant organism isolated from HIV infected children with chronic otitis media.Fungal isolates are less frequently encountered in ear discharges of HIV infected children. The 4 Quinolones are the drugs of choice in treatment of Chronic suppurative otitis media in HIV infected children.

Preputial bacterial colonisation in uncircumcised male children: Is it related to phimosis?

OBJECTIVE: To evaluate the presence of uropathogens in the periurethral skin and the effect of phimosis on bacterial colonisation. METHODS: The observational cohort study was conducted in Samsun Research and Training Hospital, Samsun, Turkey from June to December, 2014, and comprised patients undergoing circumcision. Before circumcision, all children were examined in the operating room and the presence of phimosis was recorded. All patients had circumcision performed by the same surgical team under general anaesthesia. Before the procedure, samples were taken from preputial skin of all patients by swab before cleansing with polyvidone-iodine. The samples were inoculated on 5% sheep blood agar and eosin-methylene blue agar. RESULTS: The median age of the 117 children was 5 years (range: 1-12). Of the total, 19(16.2%) children had complete phimosis, and 72(61.5%) had partial phimosis. In all,91(77.7%) children had phimosis and 26(22.3%) had no phimosis. Of the 91 patients with different degrees of phimosis, 52(57.1%) had clinically significant uropathogenic bacterial colonisation >100,000 colony-forming units per millilitre [cfu/ml]). Of the 26 patients without phimosis, 13(50%) had clinically significant colonisation. Thus, there was no effect of the presence of phimosis on bacteria colonisation (p=0.655). CONCLUSIONS: Important uropathogens colonise the preputium in uncircumcised male children. There was no effect of phimosis on colonisation.

Bacteriology of middle meatal aspirate of adult patients with chronic rhinosinusitis in Lagos. University Teaching Hospital, Lagos.

BACKGROUND: Chronic rhinosinusitis (CRS) significantly lowers the quality of life of patients. The common use of broad spectrum antibiotics for its treatment may alter the pathogens that promote the persistence of this condition. However, the data concerning the distribution of bacteria species. in patients with CRS are not consistent. OBJECTIVE: To isolate the common aerobic and anaerobic bacteria from the middle meatal aspirates of adult patients with CRS and determine their antibiotic sensitivity patterns Methods: This was a case-control study of adults with diagnosis of CRS. Middle meatal aspirate and swab were obtained from cases and control respectively for bacteriological studies. Data analysis was done using Statistical package for social sciences (SPSS) version 17 Result: Forty one aerobic bacteria were cultured. Sixty one percent of the aerobic bacteria isolated were gram positive (staphlylococcus.aureus was the most frequently found) organisms while the remaining 39% was gram negative. Fifteen peicent of the cultured isolates yielded mixed growth of both aerobes (Gram positive and gram negative).3(6%) isolates of Bacteroides species were cultured Conclusion: The present study found that Staphylococcus aureus, streptococcus pneumoniae, Proteus mirabilis, Klebsiella spp, Escherichia coli and Bacteroides spp) were the common bacterial flora in the paranasal sinuses of patients with CRS.

Antibiotic resistance patterns of bacteria causing urinary tract infections in the elderly living in nursing homes versus the elderly living at home: an observational study.

BACKGROUND: Antibiotic resistance is a problem in nursing homes. Presumed urinary tract infections (UTI) are the most common infection. This study examines urine culture results from elderly patients to see if specific guidelines based on gender or whether the patient resides in a nursing home (NH) are warranted. METHODS: This is a cross sectional observation study comparing urine cultures from NH patients with urine cultures from patients in the same age group living in the community. RESULTS: There were 232 positive urine cultures in the NH group and 3554 in the community group. Escherichia coli was isolated in 145 urines in the NH group (64%) and 2275 (64%) in the community group. There were no clinically significant differences in resistance. Combined, there were 3016 positive urine cultures from females and 770 from males. Escherichia coli was significantly more common in females 2120 (70%) than in males 303 (39%) (p < 0.05). Enterococcus faecalis was significantly less common in females 223 (7%) than males 137 (18%) (p < 0.05). For females, there were lower resistance rates to ciprofloxacin among Escherichia coli (7% vs 12%; p < 0.05) and to mecillinam among Proteus mirabilis (3% vs 12%; p < 0.05). CONCLUSIONS: Differences in resistance rates for patients in the nursing home do not warrant separate recommendations for empiric antibiotic therapy, but recommendations based on gender seem warranted.

Molecular characteristics of Salmonella genomic island 1 in Proteus mirabilis isolates from poultry farms in China.

Six out of the 64 studied Proteus mirabilis isolates from 11 poultry farms in China contained Salmonella genomic island 1 (SGI1). PCR mapping showed that the complete nucleotide sequences of SGI1s ranged from 33.2 to 42.5 kb. Three novel variants, SGI1-W, SGI1-X, and SGI1-Y, have been characterized. Resistance genes lnuF, dfrA25, and qnrB2 were identified in SGI1 for the first time.

Antimicrobial susceptibilities of Proteus mirabilis: a longitudinal nationwide study from the Taiwan surveillance of antimicrobial resistance (TSAR) program.

BACKGROUND: Longitudinal nationwide data on antimicrobial susceptibility in Proteus mirabilis from different sources are rare. The effects of the revised Clinical and Laboratory Standards Institute (CLSI) ß-lactam breakpoints on susceptibility rates and on detecting extended-spectrum ß-lactamase (ESBL) and AmpC ß-lactamase-producers in this species are also seldom evaluated. The present study analyzed data from the Taiwan Surveillance of Antimicrobial Resistance program to address these issues. METHODS: Isolates were collected biennially between 2002 and 2012 from 25 to 28 hospitals in Taiwan. Minimum inhibitory concentrations (MIC) were determined by reference broth microdilution method. All isolates with aztreonam, ceftazidime, or cefotaxime MIC ≥ 2 mg/L were checked for the presence of ESBL by CLSI confirmatory test and subjected to ESBL and AmpC ß-lactamases gene detection by PCR. Univariate and multivariate analyses were performed. RESULTS: Between 2002 and 2012, a total of 1157 P. mirabilis were studied. Susceptibility to cefotaxime, ceftazidime, and ciprofloxacin decreased significantly during the past decade, from 92.6% to 81.7%, 100% to 95.2%, and 80.1% to 53.8%, respectively (P < 0.01). The revised CLSI breakpoints had significant impact on susceptibility to cefazolin (2009 vs. current breakpoints, 71.9% vs. 0.9%) and imipenem (99.8% vs. 55.1%) (P < 0.001 for both). However, using the 2014 cefazolin breakpoints for urinary tract infections, 81.2% of the urine isolates were susceptible. Susceptibilities of isolates from different specimen types were mostly similar but outpatient isolates were more susceptible than inpatient isolates. The overall prevalence of ESBL- and AmpC- producers was 8.2% and 4.7%, respectively, but AmpC carriage increased significantly over the years (from 0 to 7.0%, P < 0.001). ESBL and AmpC ß-lactamase-producers were more likely to be found in elderly and ICU patients. The predominant ESBL and AmpC ß-lactamase genes were CTX-M- and CMY- types, respectively. CONCLUSIONS: A significant decrease in susceptibility to 3rd-generation cephalosporins and ciprofloxacin occurred in P. mirabilis from Taiwan in the past decade. The prevalence of ESBL remained stable but AmpC ß-lactamase-producing P. mirabilis increased significantly. Cefotaxime was a better surrogate than ceftazidime for predicting the presence of these ß-lactamases. Continuous surveillance on antimicrobial resistance and associated resistance mechanisms in P. mirabilis is warranted.

Proteus species bloodstream infections: Comparative epidemiology of three species.

BACKGROUND: Although Proteus species are occasional causes of serious infections, their epidemiology has not been well defined. The objective was to describe the overall and species-specific occurrence and determinants of Proteus species bloodstream infection (BSI) in a large Australian population. METHODS: All Queensland residents with Proteus species BSI identified within the publicly funded healthcare system between 2000 and 2019 were included. RESULTS: A total of 2,143 incident episodes of Proteus species BSI were identified among 2,079 Queensland residents. The prevalence of comorbid illness differed with higher Charlson comorbidity scores observed with P. penneri and P. vulgaris, and higher prevalence of liver disease with P. penneri, higher comorbid cancer with P. vulgaris, and lower diabetes and renal disease prevalence with P. mirabilis BSIs. CONCLUSION: This study provides novel information on the epidemiology of Proteus species BSI.

Emergence of Salmonella genomic island 1 (SGI1) among Proteus mirabilis clinical isolates in Dijon, France.

OBJECTIVES: Salmonella genomic island 1 (SGI1) is often encountered in antibiotic-resistant Salmonella enterica and exceptionally in Proteus mirabilis. We investigated the prevalence of SGI1-producing clinical isolates of P. mirabilis in our hospital (Dijon, France). METHODS: A total of 57 strains of P. mirabilis resistant to amoxicillin and/or gentamicin and/or trimethoprim/sulfamethoxazole isolated from August 2011 to February 2012 as well as 9 extended-spectrum ß-lactamase (ESBL)-producing P. mirabilis from our collection were tested for the presence of SGI1 by PCR. The complete SGI1 structure from positive isolates [backbone and multidrug resistance (MDR) region] was sequenced. RESULTS: SGI1 was detected in 7 isolates; 5 out of the 57 isolates collected during the study period (9%) and 2 out of the 9 ESBL-producing strains of our collection. The structures of the seven SGI1s were distinct. Three different backbones were identified: one identical to the SGI1 backbone from the epidemic Salmonella Typhimurium DT104, one with variations already described in SGI1-K from Salmonella Kentucky (deletion and insertion of IS1359 in the region spanning from S005 to S009) and one with a variation never detected before (deletion from S005 to S009). Six different MDR regions were identified: four simple variants containing resistance genes already described and two variants harbouring a very complex structure including regions derived from several transposons and IS26 elements with aphA1a never reported to date in SGI1. CONCLUSIONS: SGI1 variants are widely distributed among P. mirabilis clinical strains and might spread to other commensal Enterobacteriaceae. This would become a serious public health problem.

Characteristics of bacteremia caused by extended-spectrum beta-lactamase-producing Proteus mirabilis.

Although Proteus mirabilis is a common human pathogen, bacteremia caused by the organism, especially strains producing extended-spectrum beta-lactamase (ESBL), has rarely been investigated. We examined 64 cases of P. mirabilis bacteremia identified in the Minami Ibaraki Area, Japan, between 2001 and 2010 and compared the characteristics of cases with ESBL-producing and ESBL-non-producing strains (13 and 51 cases, respectively). All ESBL-producing strains with the gene encoding the CTX-M-2-group were genetically nonidentical. Isolation of ESBL-producing strains was significantly associated with onset in a hospital (p = 0.030), receiving hemodialysis (p = 0.0050), and previous antibiotic use within 1 month (p = 0.036; especially penicillin and/or cephalosporin (p = 0.010) and fluoroquinolone (p = 0.0069)). Isolation was also associated with inappropriate antibiotic therapy on the 1st and 4th days (p = 0.011 and 0.032, respectively) but not with mortality on the 30th day. These findings indicate that, for P. mirabilis bacteremia, isolation of ESBL-producing strains causes delay of initiating appropriate antimicrobial therapy but may not be associated with mortality.

Outcomes in UK patients with hospital-acquired bacteraemia and the risk of catheter-associated urinary tract infections.

PURPOSE: There is lack of contemporary outcome data on patients with hospital-acquired infections that cause bacteraemia. We determined the risk factors for 7-day mortality and investigated the hypothesis that, compared with central venous catheter (CVC)-associated bacteraemic infections, catheter-associated bacteraemic urinary tract infections (UTIs) were significantly associated with 7-day mortality. METHODS: From October 2007 to September 2008, demographical, clinical and microbiological data were collected on patients with hospital-acquired bacteraemia. Patients were followed until death, hospital discharge or recovery from infection. Risk factors for 7-day mortality were determined and multivariate logistic regression was used to define the association between catheter-associated bacteraemic UTIs and likelihood of death. RESULTS: 559 bacteraemic episodes occurred in 437 patients. Overall, there were 90 deaths (20.6%) at 7 days and 153 deaths (35.0%) at 30 days. Among patients with catheter-associated bacteraemic UTIs, 7-day and 30-day mortalities associated with each bacteraemic episode were 25/83 (30.1%) and 33/83 (39.8%), respectively. Within this subgroup, the commonest isolates were Escherichia coli, 36 (43.4%), Proteus mirabilis, 11 (13.3%) and Pseudomonas aeruginosa, 9 (10.8%). There were 22 (26.5%) multiple drug-resistant isolates and, of the E coli infections, 6 (16.7%) were extended spectrum ß-lactamase producers. In univariate analysis, the variables found to have the strongest association with 7-day mortality were age, Pitt score, Charlson comorbidity index (CCI), medical speciality and site of infection. Compared with CVC-associated bacteraemic infections, there was a significant association between catheter-associated bacteraemic UTIs and 7-day mortality (OR 4.16, 95% CI 1.86 to 9.33). After adjustment for age and CCI, this association remained significant (OR 2.90, 95% CI 1.19 to 7.07). CONCLUSIONS: Compared with CVC-associated bacteraemic infections, catheter-associated bacteraemic UTIs were significantly associated with 7-day mortality. Efforts to reduce these infections should be prioritised.