Etiology and antibiotic resistance patterns of community-acquired urinary tract infections in J N M C Hospital Aligarh, India

Etiologic profile and antimicrobial susceptibility of community-acquired urinary tract infection in two Cameroonian towns

Background

Urinary tract infection (UTI) represents one of the most common diseases encountered in community medical practice. In resource poor settings, treatment is usually empiric due to the high cost and long duration required for reporting diagnosis by culture and antibiotic susceptibility testing. With the growing problem of drug resistance knowledge of antibiotic susceptibility pattern is pertinent for successful eradication of invading pathogens. Our study, the first of its kind in Cameroon, analyzed the distribution and antibiotic susceptibility of bacteria causing community-acquired urinary tract infection (CAUTI) in two towns (Bamenda and Buea) with a large number of young and middle aged persons, to provide data that could guide empiric treatment.

Findings

We cultured 235 urine specimens and analyzed the antibiotic susceptibility of isolates by the disc diffusion technique. Uropathogens were recovered from 137 (58.3%), with prevalence rates in Buea and Bamenda being 65.9% and 54% respectively. Predominant pathogens were Escherichia coli (31.4%), Klebsiella oxytoca (25.5%) and Staphylococcus spp (24.1%). Geographic variation in uropathogen distribution and antibiotic susceptibility was observed, and a significant difference in pathogen distribution with respect to gender. The 20–39 years age group had the highest prevalence of infection. All pathogens isolated were detected in this group. Isolates exhibited low susceptibility to antibiotics tested. Bamenda isolates generally exhibited lower susceptibility compared to those from Buea.

Conclusion

Regional variation in etiology of CAUTI and antibiotic susceptibility observed in our study emphasizes the need to establish local and national antimicrobial resistance monitoring systems in Cameroon to provide information for the development of CAUTI treatment guidelines.

Alterations in antibiotic susceptibility of urinary tract infection pathogens

BACKGROUND

Urinary tract infection (UTI) is the third most common infection in human. New resisted strains of uropathogens have been developed due to different factors such as widespread use of antibiothics.

OBJECTIVES

We conducted this study to assess the recent pattern and susceptibility of uropathogens.

MATERIALS AND METHODS

This descriptive cross-sectional study was carried on 32600 ambulatory patients' urine samples from six laboratories from 2008 to 2010 in Ahvaz, Khuzestan. Of those, 3000 positive culture were found. Data including underlying disease, pregnancy, catheterization and drug history were gathered by questionnaire. Susceptibility of pathogens to eight antimicrobial agents was determined.

MATERIALS AND METHODS

This descriptive cross-sectional study was carried on 32600 ambulatory patients' urine samples from six laboratories from 2008 to 2010 in Ahvaz, Khuzestan. Of those, 3000 positive culture were found. Data including underlying disease, pregnancy, catheterization and drug history were gathered by questionnaire. Susceptibility of pathogens to eight antimicrobial agents was determined.

RESULTS

Mean age of patients was 33.87 ± 3.80 years and 84.9% of them were female. The results showed that, E. coli, Kelebsiella and Enterobacter were the most common pathogens (73.5%, 13.8% and 6.6%, respectively). E. coli was susceptible to Ciprofloxacin, Amikacin, and Nitrofurantoin in 76.9%, 76.4% and 76.1% of cases, respectively. Klebsiella was more susceptible to Ciprofloxacin, Ceftizoxim and Amikacin in 81.1%, 79.9% and 87.7% of positive cultures. Enterobacter was most susceptible to Ciprofloxacin (71.7%), but completely resistant to Ampicillin unexpectedly.

CONCLUSIONS

E. coli and other isolates were more sensitive to Gentamicin, Amikacin and Ciprofloxacin compared to the other antibiotics tested and therefore these may be the drugs of choice for the empiric treatment of community-acquired UTI in our region.

Prevalence of plasmid mediated bla(TEM-1) and bla(CTX-M-15) type extended spectrum beta-lactamases in patients with sepsis

OBJECTIVE

To characterize the bacterial pathogens in patients having gram negative septicaemia. Further, to evaluate the antimicrobial resistance and underlying molecular mechanisms in these strains.

METHODS

A total number of 70 cases of gram negative sepsis were included in this prospective, open labeled, observational study. Standard methods for isolation and identification of bacteria were used. Antimicrobial susceptibility and ESBL testing was performed by the standard disc diffusion method. PCR amplification was performed to identify bla(CTX-M), bla(SHV) and bla(TEM) type ESBLs. Conjugation experiments were performed to show resistant marker transfer.

RESULTS

The most prevalent isolates Escherichia coli (E. coli) 58.6%, Klebsiella Spp. 32.9% and Pseudomonas 8.6%, were resistant to most of the antimicrobials including cefazolin, ceftriaxone, cefuroxime, ampicillin and co-trimoxazole but sensitive to imipenem and meropenem. ESBL and MBL production was seen 7.3% and 12.2% of E. coli isolates respectively. Three isoaltes were found to have bla(CTX-M-15) and two of them also showed bla(TEM-1) type enxyme. Whereas, none of them showed bla(SHV). Conjugation experiments using J-53 cells confirmed these resistant markers as plasmid mediated.

CONCLUSIONS

This work highlights the molecular epidemiology of escalating antimicrobial resistance and likely switch over of bla(CTX-M-15) type extended spectrum beta-lactamases by bla(TEM) type ESBLs in India. Further, the antimicrobial resistance by horizontal gene transfer was predominant among Enterobacteraceae in the community setting.

High prevalence of multidrug resistance in bacterial uropathogens from Kathmandu, Nepal

BACKGROUND

Urinary Tract Infection (UTI) is one of the most common infectious diseases and people of all age-groups and geographical locations are affected. The impact of disease is even worst in low-resource developing countries due to unaware of the UTIs caused by multidrug-resistant (MDR) pathogens and the possibility of transfer of MDR traits between them. The present study aimed to determine the prevalence of MDR bacterial isolates from UTI patients, the antibiotic resistance pattern and the conjugational transfer of multidrug resistance phenotypes in Escherichia coli (E. coli).

RESULTS

Two hundred and nineteen bacterial isolates were recovered from 710 urine samples at Kathmandu Model hospital during the study period. All samples and isolates were investigated by standard laboratory procedures. Among the significant bacterial growth (30.8%, 219 isolates), 41.1% isolates were MDR. The most prevailing organism, E. coli (81.3%, 178 isolates) was 38.2% MDR, whereas second most common organism, Citrobacter spp. (5%, 11 isolates) was found 72.7% MDR. Extended-spectrum β-lactamase (ESBL) production was detected in 55.2% of a subset of MDR E. coli isolates. Among the 29 MDR E. coli isolates, plasmids of size ranging 2-51 kb were obtained with different 15 profiles. The most common plasmid of size 32 kb was detected in all of the plasmid-harbored E. coli strains. The majority of E. coli isolates investigated for the multidrug resistance transfer were able to transfer plasmid-mediated MDR phenotypes along with ESBL pattern with a frequency ranging from 0.3 × 10-7 to 1.5 × 10-7 to an E. coli HB101 recipient strain by conjugation. Most of the donor and recipient strain showed high levels of minimum inhibitory concentration (MIC) values for commonly-used antibiotics.

CONCLUSIONS

The high prevalence of multidrug resistance in bacterial uropathogens was observed. Particularly, resistance patterns were alarmingly higher for amoxycillin, co-trimoxazole, flouroquinolones and third-generation cephalosporins, which necessitate the re-evaluation of first and second line therapies for UTI. In addition, conjugational co-transfer of MDR phenotypes with ESBL-positive phenotypes was observed in MDR E. coli.

Relationship between urinary tract infection categorization and pathogens' antimicrobial susceptibilities

BACKGROUND

Urinary tract infections (UTIs) can be hard to treat and treatment plans need to include accurate categorization such as uncomplicated or complicated UTI, or catheterized or uncatheterized UTI. We investigated the antibiotic susceptibilities of representative uropathogens in UTI categories.

METHODS

We isolated uropathogens and analyzed their antimicrobial susceptibilities according to UTI categorization such as: (1) urology outpatients, urology inpatients, or other department inpatients; (2) uncomplicated or complicated UTIs; (3) upper or lower UTIs, and (4) non-catheterized or catheterized UTIs.

RESULTS

Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa were representative uropathogens. Susceptibilities to levofloxacin (LVFX) in E. coli in urology outpatients (p = 0.0179), those to ceftadizime in E. coli in other department inpatients (p = 0.0327), and those to LVFX in E. faecalis in complicated UTI (p = 0.0137) significantly decreased in these 3 years compared with the previous 3 years. Susceptibilities of upper UTI to LVFX in E. coli were significantly lower in the recent 4 years compared to lower UTI (p = 0.0452) and those of catheterized UTI to LVFX in E. faecalis were significantly lower than in non-catheterized UTI (p = 0.0153).

CONCLUSIONS

Data demonstrated different tendencies of uropathogens' antibiotic susceptibilities according to UTI categorizations and they could be useful for planning UTI treatments.

Prevalence of integrons, blaCTX-M and blaTEM resistance markers among ESBL-producing uropathogenic Escherichia coli isolates: first report of genomic blaCTX-M from India

Integrons have been observed to be frequently associated with uropathogenic bacteria. This study aimed at 1) determining the prevalence of class 1 integrons among ESBLl-producing uropathogenic Escherichia coli, and 2) analyzing resistance genes associated with different phylogenetic groups of the integron-positive isolates with special reference to bla(CTX-M) and bla(TEM). Twenty-three ESBL-producing E. coli were studied. Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) displayed 14 major patterns. Pulse field Gel electrophoresis-typing of 8 randomly selected integron-positive strains ruled out any correlation between genotype and antibiotype. Genomic DNA from 14 strains was PCR-positive for class 1 integrons, bla(CTX-M-15) and bla(TEM-1)-like genes. Integron-sequencing revealed "aadA5-dfrA17-dfrA7" as the most prevalent gene cassette. Our findings unveil the increasing role of the bla(CTX-M) genes in antibiotic resistance and emphasize on the significance of appropriate empirical treatment for Urinary tract infections. Moreover, this is the first study which reports bla(CTX-M) located on genomic DNA of bacteria from India.

Managing urinary tract infections

Urinary tract infections (UTI) are common in childhood. Presence of pyuria and bacteriuria in an appropriately collected urine sample are diagnostic of UTI. The risk of UTI is increased with an underlying urological abnormality such as vesicoureteral reflux, constipation, and voiding dysfunction. Patients with acute pyelonephritis are at risk of renal scarring and subsequent complications such as hypertension, proteinuria with and without FSGS, pregnancy-related complications and even end-stage renal failure. The relevance and the sequence of the renal imaging following initial UTI, and the role of antimicrobial prophylaxis and surgical intervention are currently undergoing an intense debate. Prompt treatment of UTI and appropriate follow-up of those at increased risk of recurrence and/or renal scarring are important.

Decreased susceptibility to commonly used antimicrobial agents in bacterial pathogens isolated from urinary tract infections in Rwanda: need for new antimicrobial guidelines

The aim of this study was to obtain data on susceptibility patterns of pathogens responsible for both community and hospital urinary tract infections (UTIs); and analyzed risk factors for infection caused by ciprofloxacin-resistant Escherichia coli and extended-spectrum β-lactamase (ESBL)-producing strains in Rwanda. Of 1,012 urine cultures prospectively studied, a total of 196 (19.3%) yielded significant growth of a single organism. The most common isolate (60.7%) was Escherichia coli. The antibiotics commonly used in UTIs are less effective except Fosfomycin-trometamol and imipinem. The use of ciprofloxacin in the previous 6 months (odds ratio [OR] = 7.59 [1.75-32.74]), use of other antibiotics in the previous 6 months (OR = 1.02 [1.02-2.34]), and production of ESBL (OR = 19.32 [2.62-142.16]) were found to be associated with ciprofloxacin resistance among the E. coli isolates. Risk factors for ESBL positivity were the use of ciprofloxacin and third-generation cephalosporin in the preceding 6 months (OR = 3.05 [1.42-6.58] and OR = 9.78 [2.71-35.25], respectively); and being an inpatient (OR = 2.27 [1.79-2.89]). Fosfomycin-trometamol could be included as a reasonable alternative for the therapy of uncomplicated UTI in Rwanda.

Clinico-microbiological profile of urinary tract infection in south India

The knowledge of etiology and antibiotic resistance pattern of the organisms causing urinary tract infection is essential. This study was taken up to determine the presentation and risk factors associated with community-acquired urinary tract infection (CA-UTI). The distribution of bacterial strains isolated from these patients and their resistance pattern were also studied. This multidisciplinary prospective observational study was conducted in M. S. Ramaiah Hospital, Bangalore, between January and December, 2008. Patients who had CA-UTI confirmed by positive urine culture reports were included in the study. Statistical analysis was done using the SPSS version 16. Symptomatology and others risk factors for CA-UTI were studied in these patients and the causative organisms and their resistance patterns were recorded. Of the total 510 patients included, 57% belonged to the elderly age group (50–79 years). Fever and dysuria were the most common clinical presentation, but were not specific in predicting CA-UTI. Escherichia coli (66.9%) was the most common organism causing CA-UTIs with extended spectrum beta lactamase (ESBL) resistance seen in nearly two-thirds of these cases (42.2%). The organisms recorded least resistance against carbapenems (3.9%). A high resistance rate was seen for fluoroquinolones (74.1%). In conclusion, a high rate of ESBL-positive organisms and their resistance to commonly used antibiotics brings a concern for future options in treating these conditions.

Characteristics of first urinary tract infection with fever in children: a prospective clinical and imaging study

BACKGROUND

Our objective is to provide the clinical characteristics, uropathogen frequencies, and antimicrobial resistance rates of first urinary tract infection (UTI) diagnosed in febrile Belgian children. The ability of noninvasive ultrasound to detect renal abnormalities and vesicoureteral reflux (VUR) in these patients was also assessed.

METHODS

We prospectively followed (median, 20 months) 209 children treated for first febrile UTI. Renal ultrasound (US) and voiding cystourethrography examinations were performed in all patients.

RESULTS

Among these children, 63% were females and 37% were males, and 75% of them had their first UTI before the age of 2 years. The most common causative agent was Escherichia coli (91% of cases) with high rate resistance to ampicillin (58%) and trimethoprim/sulfamethoxazole (38%). Of these children, 25% had evidence of VUR (15 boys and 38 girls). VUR was of low grade in 85% of cases. The overall performance of renal US as a diagnostic test to detect significant uropathies excluding low-grade VUR was excellent; the sensitivity attained 97% and the specificity 94%.

CONCLUSION

Girls represent 63% of cases with first UTI. For 91% of UTIs, Escherichia coli is held responsible with a high rate of resistance to ampicillin and trimethoprim/sulfamethoxazole. US is an excellent screening tool that allows avoidance of unjustified voiding cystourethrography studies.

Antibacterial activity of natural spices on multiple drug resistant Escherichia coli isolated from drinking water, Bangladesh

BACKGROUND

Spices traditionally have been used as coloring agents, flavoring agents, preservatives, food additives and medicine in Bangladesh. The present work aimed to find out the antimicrobial activity of natural spices on multi-drug resistant Escherichia coli isolates.

METHODS

Anti-bacterial potentials of six crude plant extracts (Allium sativum, Zingiber officinale, Allium cepa, Coriandrum sativum, Piper nigrum and Citrus aurantifolia) were tested against five Escherichia coli isolated from potable water sources at kushtia, Bangladesh.

RESULTS

All the bacterial isolates were susceptible to undiluted lime-juice. None of them were found to be susceptible against the aqueous extracts of garlic, onion, coriander, pepper and ginger alone. However, all the isolates were susceptible when subjected to 1:1:1 aqueous extract of lime, garlic and ginger. The highest inhibition zone was observed with lime (11 mm).

CONCLUSION

Natural spices might have anti-bacterial activity against enteric pathogens and could be used for prevention of diarrheal diseases. Further evaluation is necessary.

Antimicrobial resistance among producers and non-producers of extended spectrum beta-lactamases in urinary isolates at a tertiary Hospital in Tanzania

Background

Published data on the existence and magnitude of extended spectrum beta-lactamase (ESBL) production in urinary pathogens in local setting is limited. The aim of the present study was to determine the prevalence of antimicrobial resistance and ESBL production among Escherichia coli and Klebsiella spp from urine samples in a tertiary hospital. This was a cross sectional study conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania.

Findings

A total of 270 E.coli and Klebsiella spp urinary pathogens from children and adults isolated from January to March 2010 were included in the study. E. coli and Klebsiella spp isolates were tested for antimicrobial susceptibility by the Clinical and Laboratory Standard Institute's disc diffusion method. These isolates were further screened for ESBL phenotype using cefotaxime and ceftazidime discs. Isolates with reduced sensitivity were confirmed using ESBL E-test strips. Of 270 isolates, 138 (51.1%) were E. coli and 132 (48.9%) were Klebsiella spp. ESBL was detected in 122 (45.2%) of all the isolates. ESBL- producing E. coli strains were significantly more resistance to cotrimoxazole (90.7%), ciprofloxacin (46.3%) and nalidixic acid (61.6%) than strains that did not produce ESBL (p < 0.05). Similarly, ESBL- producing Klebsiella spp strains were significantly more resistance to cotrimoxazole (92.6%), ciprofloxacin (25.0%), nalidixic acid (66.2%), and gentamicin (38.2%) than strains that did not produce ESBL (P < 0.05). Multi-drug resistance was found to be significantly (P < 0.05) more in ESBL producing isolates (90.5%) than non ESBL producers (68.9%). The occurrence of ESBL was significantly higher among isolates from inpatients than outpatients [95 (50.5%) vs. 27(32.9%)] (p = 0.008). The occurrence of ESBL was significantly higher among isolates from children than in adults [84 (54.9%) vs. 38(32.5%)] (p < 0.001).

Conclusions

High prevalence of ESBL-producing E. coli and Klebsiella spp strains was found among inpatients and children. Most of the ESBL- producing isolates were multi-drug resistant making available therapeutic choices limited. We recommend continued antibiotic surveillance as well comprehensive multi-center studies to address the emerging problem of ESBL-associated infections in order to preserve the continued usefulness of most antimicrobial drugs. Further more conducting molecular studies will help to evaluate the various ESBL types.

Risk factors for antimicrobial resistance among the Escherichia coli strains isolated from Korean patients with acute uncomplicated cystitis: a prospective and nationwide study

We investigated the risk factors for resistance to ciprofloxacin, cefazolin, ampicillin and co-trimoxazole in Escherichia coli isolates from urine of Korean female patients with acute uncomplicated cystitis (AUC). A total of 225 patients and their E. coli isolates were prospectively and nationwidely enrolled between May and October, 2006. All the antimicrobials did not show any differences according to the age group. A higher rate of ciprofloxacin resistance was observed in the south (OR: 3.04, 95% CI: 1.19-7.80 for Chungcheong-do & Jeolla-do; OR: 3.04, 95% CI: 1.22-7.58 for Gyeongsang-do) compared to Gyeonggi-do. Two recurrences of AUC in the past year was an important risk factor for antimicrobial resistance (ciprofloxacin; OR: 6.71, 95% CI: 1.86-24.11 and cefazolin; OR: 5.72, 95% CI: 1.20-27.25). However, the resistance to co-trimoxazole and ampicillin was not associated with any of the risk factors. This study also revealed the pattern of multi-drugs resistance in ciprofloxacin resistant E. coli strains. In conclusion, for Korean patients with two more recurrences of AUC in the past year, it is strongly recommended to perform an antimicrobial sensitivity test with a urine sample before empirical treatment.

Increasing resistance in community-acquired urinary tract infections in Latin America, five years after the implementation of national therapeutic guidelines

BACKGROUND

The worldwide increasing resistance to antibiotics has complicated antimicrobial treatment of urinary tract infections (UTIs), especially in Latin America. This study aimed to report the present etiology and antimicrobial susceptibility of UTIs, and the effects of the national guidelines for UTIs introduced in 2003.

METHODS

Urine samples were collected from 304 patients with a clinical suspicion of UTI at the university hospital and primary health centers of León, Nicaragua. When bacterial growth was reported, antimicrobial susceptibility tests for nine frequently used antibiotics were performed.

RESULTS

Ninety-one (29.9%) patients had a positive urine culture. The most frequently isolated microorganisms were Escherichia coli (n=44), Serratia spp (n=11), and Escherichia fergusonii (n=10). High resistance rates were observed in E. coli to ampicillin (61.4%), cefalothin (45.5%), trimethoprim-sulfamethoxazole (38.6%), ciprofloxacin (31.8%), and ceftriaxone (20.5%). Amikacin and nitrofurantoin were the only drugs to which >90% of E. coli were susceptible. E. fergusonii and Serratia spp showed comparable high resistance patterns. Thirteen strains (29.5%) of E. coli were suspected to produce extended-spectrum beta-lactamase (ESBL).

CONCLUSIONS

Resistance rates in community-acquired UTIs in Nicaragua are increasing. The introduction of therapeutic guidelines with ceftriaxone recommended for upper UTIs and nitrofurantoin for lower UTIs, has led to increasing resistance against both antibiotics. The emergence of ESBL-producing E. coli is worrisome, along with the appearance of Serratia spp in the population.

Microbial evaluation and public health implications of urine as alternative therapy in clinical pediatric cases: health implication of urine therapy

BACKGROUND

Cultural means of pediatric treatment during ill health is a mainstay in Africa, and though urine has been known to contain enteric pathogens, urine therapy is still culturally applicable in some health conditions and also advocated as alternative therapy. The study therefore, is to evaluate the microbial contents and safety of urine.

METHODS

Urinary bacteria from cows and healthy children aged 5-11 years were identified by conventional phenotypic methods and antimicrobial susceptibility testing was performed using modified agar disc and well-diffusion methods.

RESULTS

A total of 116 bacterial isolates (n = 77 children; n = 39 cows) were identified as Bacillus (10.4%; 5.1%)), Staphylococcus (2.6%; 2.6%), Citrobacter (3.9%; 12.8%), Escherichia coli (36.4%; 23.1%), Klebsiella (7.8%; 12.8%), Proteus (18.2%; 23.1%), Pseudomonas (9.1%; 2.6%), Salmonella (3.9%; 5.1%) and Shigella (7.8%; 12.8%) spp. Antibiotic resistance rates of the Gram-positive bacteria were high (50.0100%), except in Bacillus strains against chloramphenicol, gentamicin and tetracycline (14.3%), while higher resistance rates were recorded among the Gram-negative bacteria except in Citrobacter (0.0%) and Proteus (8.5%) spp. against gentamicin and tetracycline respectively. The Gram-negative bacteria from ito malu (cow urine) were more resistant bacteria except in Citrobacter (20.0%) and Shigella spp. (0.0%) against tetracycline and Proteus spp. (11.1%), (22.2%) against amoxicillin and tetracycline respectively. Multiple antibiotic resistance (MAR) rates recorded in children urinal bacterial species were 37.5-100% (Gram-positive) and 12.5-100% (Gram-negative), while MAR among the cow urinal bacteria was 12.5-75.0% (Gram-positive) and 25.0-100% (Gram-negative). Similar higher resistance rates were also recorded among the Gram-negative bacterial species from urine specimens against the pediatric antibiotic suspensions.

CONCLUSION

The study reported presence of multiple antibiotic-resistant indicator bacteria in human urine and ito malu used as alternative remedy in pediatric health conditions like febrile convulsion.

Extended-spectrum beta-lactamase-producing Escherichia coli in patients with travellers' diarrhoea

The identification of patients carrying extended-spectrum beta-lactamase (ESBL)-producing bacteria is important, since these patients are at risk of receiving inappropriate empirical therapy if they become infected. The purpose of this study was to investigate the occurrence of ESBL-producing bacteria in patients with travellers' diarrhoea. Patients with travellers' diarrhoea (N = 242) having delivered stool samples for the diagnosis of Salmonella, Shigella, Yersinia or Campylobacter, were also examined for ESBL-producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. The overall prevalence of faecal carriage of ESBL-producing bacteria was 24% (58/242). Of the patients who had travelled in Europe, 3% (2/63) were found to be ESBL carriers in comparison to 36% (50/138) of those who had travelled outside Europe. ESBL-producing E. coli was especially common among patients returning from India (11/14), Egypt (19/38; 50%) and Thailand (8/38; 22%). In total, 90% of the genes of the ESBL-positive samples were of CTX-M type. The CTX-M-1 group dominated, followed by the CTX-M-9 group. The repetitive sequence-based PCR fingerprint pattern showed that there was no similarity between the ESBL strains found. Patients who have travelled outside Europe are at high risk of being colonized with ESBL-producing Enterobacteriaceae, and, if infected, are also at risk of receiving inappropriate empirical antibiotic therapy.

Risk factors in community-acquired urinary tract infections caused by ESBL-producing bacteria in children

In this study, risk factors were investigated in children with community-acquired urinary tract infections (UTI) caused by extended-spectrum beta-lactamases (ESBL)-producing E. coli or Klebsiella spp. One hundred and fifty-five patients were diagnosed with ESBL-positive UTI (case group) in the outpatient clinics of Hacettepe University Children's Hospital between 1 January 2004 and 31 December 2006. A control group, 155 out of 4,105 children, was matched by age and sex among children with ESBL-negative UTI. A total of 310 patients' files were evaluated retrospectively. As regards the symptoms of UTI, no statistical differences were seen between the two groups. Although the most frequently isolated microorganism was E. coli in both groups, Klebsiella spp. was found to be more frequent in those diagnosed with ESBL(+) UTI (p < 0.001). Having an underlying disease and hospitalization, infections, and use of antibiotics within the last 3 months were found to be potential risk factors (p < 0.001). With conditional logistic regression analysis, having an underlying disease and hospitalization within the last 3 months were identified as independent risk factors for ESBL(+) UTI. In conclusion, the recognition of risk factors for UTI, caused by ESBL(+) bacteria in children, may aid in the identification of high-risk cases and may enable proper management of these patients.

Acquisition of extended-spectrum beta-lactamase producing Escherichia coli strains in male and female infants admitted to a neonatal intensive care unit: molecular epidemiology and analysis of risk factors

Extended-spectrum beta-lactamases (ESBLs) are bacterial enzymes that confer resistance to advanced generation cephalosporins and can lead to therapeutic failures. There has been no analysis of factors associated with the risk of acquisition of ESBLs in neonates in an intensive care unit from northern India. The CTX-M ESBL enzymes impart resistance against advanced generation cephalosporins (e.g. cefotaxime) and CTX-M variants have become the most prevalent ESBLs worldwide. The CTX-M-15 enzyme in particular is increasingly being reported from Escherichia coli isolates from northern India together with TEM-1. Moreover, E. coli is the most common cause of neonatal sepsis. Accordingly, this study aimed to: (i) characterize the mode of transmission of bla(CTX-M) and bla(TEM) among ESBL-producing E. coli strains isolated from patients admitted to a neonatal intensive care unit (NICU), and (ii) identify factors associated with the acquisition of the said strains in male and female neonates. A total of 97 ESBL-producers was identified among 266 E. coli strains isolated from 238 neonates. The isolates were screened for bla(CTX-M), bla(TEM), armA, rmtA and rmtB, the last three genes being responsible for aminoglycoside resistance. PCR amplified bla(CTX-M) genes were cloned and sequenced. Five bla(CTX-M-15), two rmtB, two bla(TEM-1) and thirteen class1 integrons were detected. All the bla(CTX-M-15) positive isolates, except one, were clonally related. Both univariate and multivariate analyses of factors for the acquisition of the said strains were performed with respect to the sex of the neonates. 'Length of stay in the NICU' was found to be the single independent factor associated with ESBL acquisition. In conclusion, our data suggest that male neonates who are colonized or infected by ESBL-producing E. coli have a longer stay in the NICU compared to their female counterparts. This prolonged stay may be due to male neonates becoming colonized/infected earlier than their female counterparts. Plasmid-mediated-conjugal transfer was found to be the mechanism of transfer of the bla(CTX-M-15) resistance marker in the described setting.

Risk factors for extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae acquisition in a neonatal intensive care unit

This study was made to find the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae in neonatal intensive care unit (NICU) and to identify the risk factors associated with the acquisition of these organisms. Risk factors associated with ESBL-producing E. coli and/or K. pneumoniae acquisition status of neonates were assessed. Of 253 neonates admitted, 238 entered the active surveillance system. ESBL-producing K. pneumoniae was responsible for 7 infections and 51 colonizations while ESBL-producing E. coli was responsible for 9 infections and 88 colonizations. Concurrent isolation of both the organisms occurred in 30 neonates. The logistic regression model identified 'length of stay in the NICU' as the single independent risk factor. Imipenem, cefepime and amikacin can be suggested as the drugs of choice in our study.

Molecular characterisation of trimethoprim resistance in Escherichia coli and Klebsiella pneumoniae during a two year intervention on trimethoprim use

Background

Trimethoprim resistance is increasing in Enterobacteriaceae. In 2004-2006 an intervention on trimethoprim use was conducted in Kronoberg County, Sweden, resulting in 85% reduction in trimethoprim prescriptions. We investigated the distribution of dihydrofolate reductase (dfr)-genes and integrons in Escherichia coli and Klebsiella pneumoniae and the effect of the intervention on this distribution.

Methodology/Principal Findings

Consecutively isolated E. coli (n = 320) and K. pneumoniae (n = 54) isolates phenotypicaly resistant to trimethoprim were studied. All were investigated for the presence of dfrA1, dfrA5, dfrA7, dfrA8, dfrA12, dfrA14, dfrA17 and integrons class I and II. Isolates negative for the seven dfr-genes (n = 12) were also screened for dfr2d, dfrA3, dfrA9, dfrA10, dfrA24 and dfrA26. These genes accounted for 96% of trimethoprim resistance in E. coli and 69% in K. pneumoniae. The most prevalent was dfrA1 in both species. This was followed by dfrA17 in E. coli which was only found in one K. pneumoniae isolate. Class I and II Integrons were more common in E. coli (85%) than in K. pneumoniae (57%). The distribution of dfr-genes did not change during the course of the 2-year intervention.

Conclusions/Significance

The differences observed between the studied species in terms of dfr-gene and integron prevalence indicated a low rate of dfr-gene transfer between these two species and highlighted the possible role of narrow host range plasmids in the spread of trimethoprim resistance. The stability of dfr-genes, despite large changes in the selective pressure, indirectly suggests a low fitness cost of dfr-gene carriage.

Resistance against broad-spectrum beta-lactams among uropathogens in children

The aim of this study was to investigate the prevalence trends and risk factors for urinary tract infection (UTI) caused by Enterobacteriaceae resistant to broad-spectrum beta-lactams in children. All Enterobacteriaceae uropathogens from children <15 years during the 11-year period 1997-2007 were included, and risk factors were evaluated. Of 523 Enterobacteriaceae isolated from 473 children, 30 (5.73%) were phenotypically resistant to broad-spectrum beta-lactams (18 Escherichia coli, ten Klebsiella spp, one Enterobacter spp, and one Citrobacter spp). The prevalence of resistance increased during the study period (p = 0.031). Resistance to cefoxitin was common (26/30), pointing to AmpC enzyme expression, and 2/30 isolates were resistant to carbapenems. Resistant Enterobacteriaceae were often community acquired (22/30, 73.3%) and related to male gender (p < 0.05), urinary tract abnormalities (p < 0.05), prophylactic antibiotics (p < 0.0001), longer hospitalization (p < 0.001), and UTI recurrences (p < 0.001). Co-resistance was more likely for cotrimoxazole, gentamicin, and ciprofloxacin (p < 0.0001). In conclusion, our study points to increasing prevalence of Enterobacteriaceae uropathogens resistant to broad-spectrum beta-lactams in the community setting, which limits the utility of first-line antibiotics and questions the validity of using prophylaxis after a first UTI episode.

Community-onset genitourinary tract infection due to CTX-M-15-Producing Escherichia coli among travelers to the Indian subcontinent in New Zealand

A series of patients are described who presented to a New Zealand hospital with genitourinary tract infection due to CTX-M-15-producing Escherichia coli. All had a history of travel to the Indian subcontinent and lacked traditional risk factors for urinary tract infection due to a multidrug-resistant organism.

Antimicrobial activity of five herbal extracts against multi drug resistant (MDR) strains of bacteria and fungus of clinical origin

Antimicrobial activities of the crude ethanolic extracts of five plants were screened against multidrug resistant (MDR) strains of Escherichia coli, Klebsiella pneumoniae and Candida albicans. ATCC strains of Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus bovis, Pseudimonas aeruginosa, Salmonella typhimurium, Escherichia coli, Klebsiella pneumoniae and Candida albicans were also tested. The strains that showed resistance against the maximum number of antibiotics tested were selected for an antibacterial assay. The MDR strains were sensitive to the antimicrobial activity of Acacia nilotica, Syzygium aromaticum and Cinnamum zeylanicum, whereas they exhibited strong resistance to the extracts of Terminalia arjuna and Eucalyptus globulus. Community-acquired infections showed higher sensitivity than the nosocomial infections against these extracts. The most potent antimicrobial plant was A. nilotica (MIC range 9.75-313 microg/ml), whereas other crude plant extracts studied in this report were found to exhibit higher MIC values than A. nilotica against community acquired as well as nosocomial infection. This study concludes that A. nilotica, C. zeylanicum and S. aromaticum can be used against multidrug resistant microbes causing nosocomial and community acquired infections.

Antibacterial effects of Iranian Mentha pulegium essential oil on isolates of Klebsiella sp

The aim of the present study was the evaluation of the antibacterial activity of Mentha pulegium essential oil on isolates of Klebsiella. Thirty nine isolates were collected from urine specimens submitted to two educational hospitals in Urmia, Iran. The susceptibility of isolates was determined using a broth microdilution method. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of isolates to Mentha pulegium essential oil were determined. The susceptibilities of isolates to different antibiotics were tested using agar disk diffusion method. The rates of resistance were determined to antibiotics as follows: gentamicin 46.1%, tobramycin 48.7%, ceftizoxime 41%, co-trimoxazole 46.1%, amikacin 33.3%, cephtazidime 51.3%, ciprofloxacin 30.8%, kanamycin 53.8%, nalidixic acid 30.8% ampicillin 79.5% and nitrofurantoin 41%. Mentha pulegium essential oil possessed antibacterial effect against all isolates of Klebsiella sp. with MIC and MBC values in the range of 1.9 x 10(-3) to 4.9 x 10(-4) mm3 mm(-3). In this study clinical isolates of Klebsiella sp. showed very high resistance to tested antibiotics. These results suggest the potential use of the Mentha pulegium essential oil for the control of multi-drug resistant Klebsiella sp. infections. However, more adequate toxicological study must be carried out to verify the possibility of using it for fighting microorganisms in human.

Antimicrobial resistance among neonatal pathogens in developing countries

INTRODUCTION

Knowledge of antimicrobial resistance and trends in resistance patterns among major pathogens causing infections in young infants (up to 90 days of life) is an important component of developing community-based management strategies. Hospital-based data suggest alarming rates of resistance to ampicillin and gentamicin, the first-line antimicrobial agents recommended by WHO for treatment of serious infections in young infants.

METHODS

We searched the literature published since 1990 for studies from developing countries reporting resistance among serious community-acquired infections (including sepsis, pneumonia, and meningitis) in young infants.

RESULTS

Only 10 relevant reports were retrieved. Among the 3 major pathogens studied (Escherichia coli, Staphyloccoccus aureus, and Klebsiella species), a high proportion of E. coli were ampicillin (72%) and cotrimoxazole (78%) resistant; 19% were resistant to third generation cephalosporins. Among Klebsiella species, almost all were resistant to ampicillin, 45% to cotrimoxazole, and 66% to third generation cephalosporins. Resistance to gentamicin was low among E. coli (13%), but much higher among Klebsiella species (60%). Methicillin resistance S. aureus (MRSA) was rare (1 of 33 isolates) but 46% were resistant to cotrimoxazole.

CONCLUSIONS

Antimicrobial resistance data for infections in young infants from community-based studies were extremely limited. Significant resistance, in particular to cotrimoxazole among all pathogens, and to gentamicin and third generation cephalosporins among Klebsiella and emerging resistance in E. coli is cause for concern. Limited data pose a challenge in devising simple community-based management strategies. Further studies from different developing country regions are needed to determine prevalence of resistant strains, as well as assess regional and time trends.

Urinary tract infections in a South American population: dynamic spread of class 1 integrons and multidrug resistance by homologous and site-specific recombination

One hundred four bacterial strains mediating urinary tract infections in separate individuals from a Uruguayan community were isolated. Forty-six strains conferred a multidrug resistance phenotype. All 104 strains were examined for the presence of class 1, 2, and 3 integrons. Class 1 integrons were found in 21 isolates across four distinct bacterial genera. A large class 1 integron in a Klebsiella pneumoniae strain was fully sequenced and was 29,093 bp in length. This integron probably arose by homologous recombination since it was embedded in a hybrid Tn21-like transposon backbone which comprised a Tn5036-like tnp transposition module at the IRi integron end and a Tn21 mer module at the IRt integron end. The parent integron/transposon that contributed the Tn5036 module was not related to Tn1696 since the integron insertion points in the transposon backbones were 16 bases apart. Examination of the other 20 class 1 integron-containing strains revealed further evidence of genetic exchange. This included a strain that possessed a Tn5036 module at the IRt end but not at the IRi end and another that possessed a tnp module beyond IRi that was a hybrid of Tn21 and Tn5051 and that is presumed to have arisen by site-specific recombination. This study highlights the ability of different genetic elements to act cooperatively to spread and rearrange antibiotic resistance in a community.

Urinary tract infections

Urinary tract infection (UTI), with its diverse clinical syndromes and affected host groups, remains one of the most common but widely misunderstood and challenging infectious diseases encountered in clinical practice. Antimicrobial resistance is a leading concern, with few oral options available to treat infections caused by Gram-negative organisms resistant to trimethoprim-sulfamethoxazole and fluoroquinolones, especially for patients with upper tract disease. Efforts should be made not to detect or treat asymptomatic bacteriuria and funguria; to ensure an appropriate duration of therapy for symptomatic infections; and to limit the use of broad-spectrum agents, especially fluoroquinolones, if narrower spectrum agents are available. Further research is needed regarding rapid diagnosis of UTI, accurate presumptive identification of patients with resistant pathogens, and development of new antimicrobials for drug-resistant UTI.

Distribution and Resistance Trends of Community Associated Urinary Tract Pathogens in Sharjah, UAE

Objective

To describe the spectrum of etiologic agents causing community associated UTI and their antimicrobial resistance trends in a large teaching hospital in Sharjah, United Arab Emirates.

Methods

A retrospective review of the microbiology laboratory records of four hundred ninety two cases of community associated UTI between April 2006 and March 2007 was carried out. Etiologic agents and their antimicrobial susceptibility pattern were analyzed.

Results

A wide spectrum of uropathogens was isolated of which the leading etiologic agents of community associated UTI were Escherichia coli (207 strains) and Klebsiella species (90 strains). Sixty-six per cent of Gram-negative bacilli were resistant to amoxicillin, 58.5% were resistant to trimethoprim-sulfamethoxazole and more than 50% were resistant to cephalexin. However, resistance rate to antimicrobials like ciprofloxacin and ceftriaxone remain relatively low 9.7% and 7.6% respectively.

Conclusions

Escherichia coli remains the leading cause of community associated UTI. In-vitro antimicrobial resistance pattern of the isolates revealed that trimethoprim-sulfamethoxazole, cephalexin and amoxycillin the commonly used first-line antimicrobials were becoming less and less effective in their treatment. This information can help in changing preferences of suitable antimicrobial agent in treatment of community associated UTI.

Antimicrobial susceptibility of community-acquired uropathogens in general practice

Antibiotic resistance of urinary tract pathogens has increased worldwide. The purpose of this study is to provide information regarding local resistance pattern of urinary pathogens to the commonly used antibiotics. One hundred and seventeen cases of community-acquired urinary tract infections were studied. The most common group of patients was the uncomplicated acute cystitis in women. E. coli was the most common isolate. Overall, antimicrobial susceptibility test on the organisms isolated showed a resistance of 63.0% to ampicillin, 40.1% to sulfamethoxazole-trimethoprim (S-T), 14.3% to pipemidic acid, 8.6% to norfloxacin, 3.8% to cephalexin, 3.7% to amoxicillin-clavulanate, 1.0% to cefuroxime, and 1.0% to fosfomycin. Three out of five patients on ampicillin as well as two out of five patients on S-T were likely to be inadequately treated.

Aminoglycosides versus bacteria – a description of the action, resistance mechanism, and nosocomial battleground

Since 1944, we have come a long way using aminoglycosides as antibiotics. Bacteria also have got them selected with hardier resistance mechanisms. Aminoglycosides are aminocyclitols that kill bacteria by inhibiting protein synthesis as they bind to the 16S rRNA and by disrupting the integrity of bacterial cell membrane. Aminoglycoside resistance mechanisms include: (a) the deactivation of aminoglycosides by N-acetylation, adenylylation or O-phosphorylation, (b) the reduction of the intracellular concentration of aminoglycosides by changes in outer membrane permeability, decreased inner membrane transport, active efflux, and drug trapping, (c) the alteration of the 30S ribosomal subunit target by mutation, and (d) methylation of the aminoglycoside binding site. There is an alarming increase in resistance outbreaks in hospital setting. Our review explores the molecular understanding of aminoglycoside action and resistance with an aim to minimize the spread of resistance.