Quinolone resistance and ornithine decarboxylation activity in lactose-negative Escherichia coli

Quinolones and fluoroquinolones are widely used to treat uropathogenic Escherichia coli infections. Bacterial resistance to these antimicrobials primarily involves mutations in gyrA and parC genes. To date, no studies have examined the potential relationship between biochemical characteristics and quinolone resistance in uropathogenic E. coli strains. The present work analyzed the quinolone sensitivity and biochemical activities of fifty-eight lactose-negative uropathogenic E. coli strains. A high percentage of the isolates (48.3%) was found to be resistant to at least one of the tested quinolones, and DNA sequencing revealed quinolone resistant determining region gyrA and parC mutations in the multi-resistant isolates. Statistical analyses suggested that the lack of ornithine decarboxylase (ODC) activity is correlated with quinolone resistance. Despite the low number of isolates examined, this is the first study correlating these characteristics in lactose-negative E. coli isolates.

Occurrence of genes encoding enterotoxins in uropathogenic Escherichia coli isolates

To determine the presence of some toxins of diarrheagenic Escherichia coli (DEC) in uropathogenic E. coli (UPEC), 138 urinary tract infection (UTI)-causing UPECs were analyzed. The astA, set, sen and cdtB genes were detected in 13 (9.4%), 2 (1.3%), 13 (9.4%) and 0 (0%) of UPEC isolates respectively. The results show that some genes encoding toxins can be transferred from DEC pathotypes to UPECs therefore these isolates can transform into potential diarrhea-causing agents.

Prevalência de uropatógenos e perfil de sensibilidade aos antimicrobianos em pacientes ambulatoriais de Jataí-GO / Prevalence of uropathogens and antimicrobial susceptibility profile in outpatient from Jataí-GO

Introduction: Urinary tract infections (UTIs) affect people worldwide. Escherichia coli is the main agent of UTI, however the etiology may vary according to the age and sex of the patient. Regional variations in the prevalence and antimicrobial resistance should be considered for therapy choice. Objectives: This study aimed to conduct a survey on the main agents of UTI, and assess the resistance of these microorganisms, during the period of March 2010 to June 2012 in the city of Jataí-GO. Method: A retrospective cross-sectional study were performed, collecting data on the prevalence of uropathogens and their sensitivity profiles which were evaluated by disk diffusion method. Results: During this period, 2,181 urine cultures were evaluated, of which 510 (23.4%) were positive, predominantly female (81.4%) and aged between 21 and 64 years old (59.7%). The most frequently isolated microorganism was E. coli (61%), followed by Staphylococcus saprophyticus (9.4%), and Proteus (9.4%). The prevalence of these bacteria according to the patient sex has suffered a statistically significant change (p < 0.05). It was possible to detect high resistance rate of E. coli to some antibiotics of choice for UTI treatment, such as ampicillin (57.9 %), pipemidic acid (50.5 %), nalidixic acid (48.6 %), and trimethoprim-sulfamethoxazole (44.8%). Conclusion: These data demonstrate the need to know the reality of each region in order to establish an appropriate empirical therapy, when it is not possible to perform culture and antimicrobial susceptibility testing...

Introdução: Infecções do trato urinário (ITU) afetam pessoas em todo o mundo. Escherichia coli é o principal agente de ITU, no entanto a etiologia pode variar de acordo com o sexo e a idade do paciente. Variações regionais quanto à prevalência e à resistência aos antimicrobianos devem ser consideradas para a escolha terapêutica. Objetivos: Este trabalho teve por objetivo realizar um levantamento sobre os principais agentes de ITU e avaliar o perfil de resistência desses microrganismos no período de março de 2010 a junho de 2012, na cidade de Jataí-GO. Método: Estudo retrospectivo de corte transversal realizado por meio de coleta de dados sobre a prevalência de uropatógenos e seus perfis de sensibilidade avaliados pelo método da difusão. Resultados: Neste período, foram realizadas 2.181 uroculturas, das quais 510 (23,4%) apresentaram resultado positivo, sendo predominantemente do sexo feminino (81,4%) e com idade entre 21 e 64 anos de idade (59,7%). O microrganismo mais frequentemente isolado foi E. coli (61%), seguido de Staphylococcus saprophyticus (9,4%) e Proteus (9,4%). A prevalência dessas bactérias, de acordo com o sexo do paciente, sofreu variação estatisticamente significativa (p < 0,05). Foi possível constatar elevada taxa de resistência de E. coli para alguns antimicrobianos de primeira escolha para tratamento de ITU, como ampicilina (57,9%), ácido pipemídico (50,5%), ácido nalidíxico (48,6%) e sulfazotrim (44,8%). Conclusão: Esses dados demonstram a necessidade de se conhecer a realidade de cada região a fim de se estabelecer uma terapia empírica adequada, quando não for possível a realização da cultura e do antibiograma...

Antimicrobial Susceptibility Pattern and ESBL Production among Uropathogenic Escherichia coli Isolated from UTI Children in Pediatric Unit of a Hospital in Kerman, Iran.

Aims: Emergence of antibiotic resistance and extended spectrum β- lactamase (ESBL) among uropathogens in the pediatric unit of hospitals created serious health care concern. This study deals with antimicrobial susceptibility and ESBL analysis of uropathogenic Escherichia coli isolated from children hospitalized in pediatric unit of a university hospital in Kerman, Iran. Methodology: Fifty-five uropathogens positive samples were recovered from one hundred thirty five samples collected from urine of the children hospitalized with sign of UTI in pediatric unit of a hospital, in Kerman, Iran from April 2011 to November 2012. Preliminary antimicrobial susceptibility testing was carried out using agar disk-diffusion breakpoint assay and minimum inhibitory concentrations (MICs) of different antibiotics were determined by agar dilution method. ESBL production was detected by a double disk synergy test and confirmed by a phenotypic confirmatory test. Results: Of fifty-five positive samples isolated, Escherichia coli (69%) was the leading uropathogen followed by Klebsiella spp. (18.8%), Proteus (7.27%), Staphylococcus aureus (3.63%), Citrobacter (1.8%), Enterobacter spp. (1.81%) and Enterococcus (1.8%). Antimicrobial susceptibility tests revealed that almost all uropathogenic E. coli were sensitive to carbapenems (100%) and amikacin (94.4%), while, 100% of the strains were resistant to ampicillin (MIC range ±32 μg/mL), 63.8% were resistant to amoxicillin/clavulanic acid (MIC range ±32μg/mL), 33% were resistant to trimethoprim- sulfamethoxazole (MIC range ±64.2μg/mL) and 61.1% of the strains were resistant to third generation of cephalosporins (MIC range ±8.0μg/mL) (P=0.05). The ESBL confirmatory test for uropathogenic E. coli isolates resistant to third generation of cephalosporins revealed that only 20% were produced detectable ESBL enzymes. Conclusion: From above results it can be concluded that E. coli was the most common nosocomial pathogen associated with UTI among hospitalized children in our hospital and amikacin, carbapenems were very effective drugs for treatment of UTI in these age group, while, care must be taken when third generation of cephalosporins and trimethoprimsulfamethoxazole are administered.

Evaluation of producing extended spectrum p-lactamase among isolated escherchia coli from patients suffering from urinary tract infections: [short report]

Despite the widespread availability of antibiotics, antibiotic resistance in uropathogens is increasing. The most common mechanism in the antibiotic resistance is production of extended spectrum B-lactamase [ESBL]. In this study, the presence of producing ESBL among isolated Escherchia Coli from patients suffering from urinary tract infections in Ali-Ebne Abitaleb hospital [Rafsanjan, Iran] as well as their sensitivity to newer antibiotics were evaluated. In this descriptive study, 146 Escherchia Coli were collected from 1634 urine samples of suspected patients with urinary tract infection in a five month tim period. Isolated organisms were identified by standard biochemical and microbial tests. Antibiotic susceptibility test was done by disc diffusion method. Isolated E coli that were resistant to third generation cephalosporines were tested for ESBL phenotype by double disc synergy test method. Their susceptibility to imipenem, meropenem and cefepime were also determined. Totally, 19.86% of the isolated E coli showed resistance to third generation cephalosporines and 10.27% of them were ESBL producer. Also, ESBLs E Coli showed co-resistance to other antibiotics. Susceptibility to imipenem, meropenem were 100%, and cefepime 26.66%. ESBL producer isolated Escherchia Coli had resistance to many different antibiotics, but it showed high susceptibility to imipenem and meropenem. So in order to prevent any resistance, we should use these antibiotics correctly

Effect of some antimicrobial agents on isolated bacteria from patients with urinary tract infection in Kurdistan Region

Urinary tract infection [UTI] defines as a condition in which the urinary tract is infected with a pathogen causing inflammation. UTI affects all age groups, but women are more susceptible than men, it is the second most common form of infection. This study was designed to isolation and identification of common uropathogenic bacteria and determining the sensitivity of infectious urinary isolated strains to different antimicrobial agents. This study included 350 patients [125 males and 225 females] with sign and symptoms of UTI, who were referred to the teaching hospital in Erbil and sulaimania cities, from march till may 2007. Also, 25 healthy individuals were included in the study as a control group. API tests and several biochemical tests were used for identification different isolated bacteria from UT. The bacterial cultivations revealed positive results for 119 [34%] urine specimens, 56 [47.05%] in males and 63 [52.94%] in females compared to control group [0%]. The highest percentage of infection was observed in females in age group [20-39] years [44.44%]. The highest rate of uropathogenic isolates was e. Coli 53 [41.08%] followed by s. Aureus, proteus sp., klebsiella sp., enterobacter sp., and pseudomonas sp. 23[17.82%], 23[17.82%], 11[8.52], 10[7.75] and 9[6.97] respectively. The uropathogenic bacterial isolates showed different susceptibility to antimicrobial agents, ciprofloxacine was the most efficient to inhibit UTI. Incidence of UTIs in females is more than in males with a higher rate in the 20-39 years age group. E. Coli was the commonest pathogenic bacteria isolated from urinary tract

Identification of uropathogenic Escherichia coli clonal group A (CgA) in hospitalised patients

This study provides the first description of healthcare-associated infections with Escherichia coli clonal group A (CgA) isolates in Latin America. Isolates were typed by enterobacterial repetitive intergenic consensus-PCR, pulsed-field gel electrophoresis, E. coli phylogenetic grouping, multilocus sequence typing and fimH single nucleotide polymorphism analysis. Out of 42 E. coli hospital isolates studied, three belonged to E. coli phylogenetic group D and ST69 and had fimH sequences identical to that of the CgA reference strain ATCC BAA-457. E. coli CgA is another potential source of resistant infections in hospitals.