[Activity of fosfomycin against extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae]

First Detection of Klebsiella pneumoniae Isolate Co-Harboring Fosfomycin Resistance Gene fosA3 and blactx-m Among Gram Negative Urine Isolates in a Turkish Hospital

The most common gram-negative pathogens in urinary tract infections are Escherichia coli and Klebsiella pneumoniae. Therapy that is often empirical relies on local antibiotic resistance data, hence monitorization of antimicrobial resistance periodically in each hospital is a requirement. In this study, antibiotic susceptibility profiles of consecutive urinary isolates (E. coli [n = 235] and K. pneumoniae [n = 56]) of adult patients collected between February 2018 and February 2019 from inpatients in Hacettepe University Hospital were assessed. Isolates resistant to fosfomycin (minimum inhibitory concentration >32 mg/L) were further investigated for the presence of fosA, fosA3, and fosC2. Fosfomycin susceptibility was determined by agar dilution method. Broth microdilution method was performed for amikacin, gentamicin, ceftazidime, ceftriaxone, meropenem, ciprofloxacin, tigecycline, trimethoprim/sulfamethoxazole (TMP/SMX), colistin, and piperacillin/tazobactam (PIP/TAZ). PCR method was employed to investigate fosA, fosA3, fosC2, and bla_CTX-M. Existence of fosA3 gene was confirmed by sequencing. Resistance rates to amikacin, gentamicin, ceftazidime, ceftriaxone, meropenem, ciprofloxacin, tigecycline, TMP/SMX, colistin, and PIP/TAZ were 2.7%, 18.5%, 25.4%, 33.0%, 3.4%, 45.4%, 2.4%, 43.6%, 6.2%, and 23.7%, respectively. Sixteen isolates (5.5%) were resistant to fosfomycin. Resistance was most frequently observed in K. pneumoniae (n = 9). fosA3 gene was detected in one fosfomycin-resistant K. pneumoniae isolate. This isolate also carried bla_CTX-M. fosC2 and fosA genes could not be detected in any of the isolates. In this study, we report for the first time the existence of fosA3 in Turkey and its association with the bla_CTX-M gene. As a result of increasing bla_CTX-M producing Enterobacterales isolates globally, increase in fosfomycin resistance may be expected in near future.

Clinico-Microbiological Investigation on Fosfomycin and Tigecycline Resistant Gram-Negative Bacilli Isolated from Urinary Tract Infections: A Potential Resurgence

Background: Traditional antibiotics are no longer as effective as before for controlling pathogens associated with urinary tract infections (UTI), which shows the necessity of developing new and more effective antibiotics. Objectives: The current study aimed to evaluate in vitro susceptibility of fosfomycin and tigecycline towards common antibiotic-resistant Gram-negative bacilli isolated from the urinary tract. Besides, clinico-microbiological on fosfomycin and tigecycline resistant Gram-negative bacilli was investigated. Methods: In this descriptive cross-sectional study, 150 resistant Gram-negative bacilli were isolated from urine specimens send for culture, and antibiotic susceptibility assessment to the Division of Microbiology of Sina Hospital affiliated to Tabriz University of Medical Sciences which were collected from April-September 2017 are included. Antibiotic susceptibilities were evaluated according to the Clinical and Laboratory Standards published by the Institute and the criteria of the Food and Drug Administration. Results: Of 150 isolates, 138 (92%) were susceptible, and 2 (1.3%) were resistant to both fosfomycin and tigecycline, as confirmed by disk diffusion and Epsilonmeter tests. The difference was statistically significant (P = 0.001). Conclusions: Based on the results, resistance to the conventional antibiotics prescribed for the treatment of UTI was significantly high. Fosfomycin and tigecycline have an appropriate antimicrobial activity towards Gram-negative-resistant isolates involved in UTIs.

Current options for the treatment of infections due to extended-spectrum beta-lactamase-producing Enterobacteriaceae in different groups of patients

BACKGROUND

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are a frequent cause of invasive infections worldwide. Carbapenems are nowadays the most used drugs to treat these infections. However, due to the increasing rates of resistance to these antimicrobials, carbapenem-sparing alternatives are being investigated.

OBJECTIVES AND SOURCES

The aim of this narrative literature review is to summarize the published information on the currently available antibiotics for the treatment of ESBL-E infections, providing specific information on three subgroups of patients: Group 1, patients with severe infections or infections from high-risk sources or in severely immunocompromised patients; Group 2, patients with non-severe infections from intermediate-risk source; and Group 3, patients with non-severe urinary tract infection.

CONTENT AND IMPLICATIONS

For patients in Group 1, the current data would support the use of carbapenems. For milder infections, however, particularly urinary tract infections, other non-carbapenem antibiotics can be considered in selected cases, including beta-lactam/beta-lactam inhibitor combinations, cephamycins, temocillin and aminoglycosides. While specific studies should be performed in these situations, individualized decisions may be taken in order to avoid overuse of carbapenems.

Molecular Epidemiology of Plasmid-Mediated Fosfomycin Resistance Gene Determinants in Klebsiella pneumoniae Carbapenemase-Producing Klebsiella pneumoniae Isolates in China

The Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae has become a serious problem because the species is wide ranging and there are few treatment options. Fosfomycin has attracted renewed interest in combination therapy for infections caused by KPC-producing K. pneumoniae isolates. Because of the increasing use of fosfomycin, resistant isolates have been continually reported in carbapenem-resistant K. pneumoniae (CRKP). At present, multiple mechanisms can result in fosfomycin resistance. However, there is limited knowledge with respect to plasmid-mediated fosfomycin resistance gene (fosA3) determinants in KPC-producing K. pneumoniae isolates. In this study, a total of 101 CRKP strains were collected from four hospitals in Zhejiang province from January 2013 to August 2014; 28.7% (29/101) of CRKP isolates were resistant to fosfomycin. Gene fosA3 was detected in 29 fosfomycin-resistant KPC-producing K. pneumoniae isolates, whereas genes fosA, fosB, fosB2, fosC, fosC2, and fosX were all negative among the resistant isolates. In addition, among 29 fosfomycin-resistant KPC-producing K. pneumoniae isolates, pulsed-field gel electrophoresis (PFGE) analysis revealed five pulsotypes. S1-PFGE and Southern blot showed that the fosA3 gene was located on an approximately 140-kb plasmid in all isolates. Eight of the 29 isolates (27.6%) tested could successfully transfer their fosfomycin-resistant phenotype to Escherichia coli strain J53. All fosA3-positive isolates were determined to have an identical genetic background, IS26-tetR-cadC-orf1-fosA3-IS26, which is the same as that of the fosA3-positive plasmid pFOS18 in China. The primary resistance mechanism to fosfomycin was caused by a plasmid-mediated fosA3. Furthermore, it is noteworthy that the plasmid genetically carrying a combination of the fosA3 and bla_KPC-2 genes could accelerate the spread of antibiotic resistance. Effective and persistent monitoring and surveillance will be vital to prevent further dissemination of these resistance genes.

The Activity of Fosfomycin Against Extended-Spectrum Beta-Lactamase-Producing Isolates of Enterobacteriaceae Recovered from Urinary Tract Infections: A Single-Center Study Over a Period of 12 Years

Despite global efforts to tackle resistance in extended-spectrum beta-lactamase (ESBL)-producing isolates via old antibiotics, there are limited data on the efficacy of fosfomycin-an old oral antibiotic-against Enterobacteriaceae in the Middle East. The purpose of this study was to evaluate the in vitro activity of fosfomycin against urinary ESBL-producing isolates of Enterobacteriaceae. Between 2004 and 2015, 363 isolates of ESBL-producing Enterobacteriaceae were recovered from high-risk patients suffering from cardiac disorders and were subjected to polymerase chain reaction using specific primers for the bla_TEM, bla_SHV, and bla_CTX-M genes. Antibiotic susceptibility testing was performed for fosfomycin and other antibiotic comparators. For the isolates considered nonsusceptible to fosfomycin by disk diffusion, the minimum inhibitory concentration (MIC) was determined. The susceptibility rate to fosfomycin remained almost steady (90-100%) over a 12-year period, although it fluctuated vis-à-vis ciprofloxacin (0-54%), trimethoprim/sulfamethoxazole (9.1-31.7%), and nitrofurantoin (41.7-100%). Of all the antibiotics tested, fosfomycin was the most active antimicrobial agent (97%) against the ESBL-positive isolates. Fosfomycin maintained higher activity against ESBL-Escherichia coli than against ESBL-Klebsiella pneumoniae. Only 11 (3%) isolates were not susceptible to fosfomycin according to disk diffusion and they had MICs greater than 1,024 mg/ml. All of the fosfomycin-nonsusceptible isolates were positive for the bla_CTX-M gene (100%), while 5 (45.4%) and 3 (27.3%) of the isolates harbored the bla_TEM and bla_SHV genes, respectively. We showed that fosfomycin had a numerically higher susceptibility rate than the other antibiotics against the ESBL-producing isolates of the most common Enterobacteriaceae. Given its low resistance rate and oral administration, fosfomycin may be deemed a promising antibiotic for the treatment of urinary tract infections caused by ESBL-producing Enterobacteriaceae.

Novel consortium of Klebsiella variicola and Lactobacillus species enhances the functional potential of fermented dairy products by increasing the availability of branched-chain amino acids and the amount of distinctive volatiles

AIMS

Identify novel bacterial taxa that could increase the availability of branched-chain amino acids and the amount of distinctive volatiles during skim milk fermentation.

METHODS AND RESULTS

We recovered 344 bacterial isolates from stool samples of healthy and breastfed infants. Five were selected based on their ability to produce branched-chain amino acids. Three strains were identified as Escherichia coli, one as Klebsiella pneumoniae and other as Klebsiella variicola by molecular and biochemical methods. HPLC and solid-phase microextraction with GC-MS were used for the determination of free amino acids and volatile compounds respectively. The consortium formed by K. variicola and four Lactobacillus species showed the highest production of Leu and Ile in skim milk fermentation. In addition, the production of volatile compounds, such as acetoin, ethanol, 2-nonanone, and acetic, hexanoic and octanoic acids, increased in comparison to commercial yogurt, Emmental and Gouda cheese. Also, distinctive volatiles, such as 2,3-butanediol, 4-methyl-2- hexanone and octanol, were identified.

CONCLUSION

The use of K. variicola in combination with probiotic Lactobacillus species enhances the availability of Leu and Ile and the amount of distinctive volatiles during skim milk fermentation.

SIGNIFICANCE AND IMPACT OF THE STUDY

The identified consortium increases the functional potential of fermented dairy products.

Fosfomycin for the treatment of drug-resistant urinary tract infections: potential of an old drug not explored fully

INTRODUCTION

Increased emergence of bacterial resistance and the limited options of novel antimicrobial agents have necessitated the reintroduction of some old antimicrobial agents. One such drug is fosfomycin, but its potential has not been explored fully, especially in India.

AIMS AND OBJECTIVES

To analyze the in vitro activity of fosfomycin, against the urinary isolates and to compare it with in vitro activity of other orally administered antimicrobial agents.

MATERIALS AND METHODS

This was a prospective observational study conducted between July 2014 and June 2016. All consecutive, non-duplicate and clinically significant urinary isolates obtained from patients of all ages and both genders, diagnosed to have UTI, were included. Patients already on antibiotic therapy were excluded. Urine culture was performed by semiquantitative method on cysteine lactose electrolyte-deficient medium and the isolates obtained in significant count were subjected to antimicrobial sensitivity testing by the Kirby Bauer disk diffusion method as per CLSI guidelines.

RESULTS

A total of 3947 non-repeating urinary isolates were included in the study, of which 2684 (68%) isolates originated from adult outpatients and remaining 1236 (32%) isolates from pediatric patients. Of these 2783 isolates were from enterobacteriaceae family. Out of these 2730 (98.1%) were sensitive to fosfomycin. Most [375 of 385 (97.4%)] Pseudomonas spp were also susceptible to fosfomycin. A majority of ESBL- (96.5%) and MBL (91.9%)-producing isolates were also susceptible to fosfomycin and so were of Gram-positive isolates [698/707 (96%)] and MRSA [61/69 (88.4%)] were susceptible to fosfomycin.

CONCLUSIONS

Fosfomycin showed an excellent in vitro activity against all urinary pathogens, including the Gram-positive or Gram-negative, ESBL and MBL producers. Fosfomycin should be considered as a highly effective alternative in treatment UTIs in both adults and pediatric patients.

Occurrence of multidrug resistance to oral antibiotics among Escherichia coli urine isolates from outpatient departments in Germany: extended-spectrum β-lactamases and the role of fosfomycin

The in vitro activities of fosfomycin and seven other antibiotics commonly used for oral treatment of urinary tract infections (UTIs) were evaluated for 499 Escherichia coli isolated from urine samples during a nationwide laboratory-based surveillance study in 2010. Overall, the highest resistance rates were found for amoxicillin (42.9%), followed by amoxicillin/clavulanic acid (32.7%), trimethoprim/sulfamethoxazole (SXT) (30.9%), ciprofloxacin (19.8%), cefuroxime (10.0%), cefpodoxime (8.6%) and cefixime (8.2%). One-half of the isolates (n=252; 50.5%) were fully susceptible to the eight drugs, whilst only 6 strains (1.2%) were resistant to fosfomycin. Combined resistance to amoxicillin, cefuroxime, ciprofloxacin and SXT was detected in 29 isolates (5.8%). Moreover, 40 isolates (8.0%) produced an extended-spectrum β-lactamase (ESBL), including CTX-M-type ESBLs detected in 39/40 isolates (97.5%) and a TEM-52 ESBL in 1 strain (2.5%). The predominant CTX-M-type ESBL was CTX-M-15 (27/39; 69.2%). Of the 27 CTX-M-15 producers, 19 (70.4%) belonged to the clonal lineage E. coli O25b-ST131. All but one ESBL-producing strains were fosfomycin-susceptible. In view of the emergence of multidrug resistance to standard oral antibiotics, these data support that oral fosfomycin (trometamol salt) may represent a valuable option in the treatment of uncomplicated UTIs.

Emergence of extended-spectrum β-lactamase-producing Escherichia coli in catheter-associated urinary tract infection in neurogenic bladder patients

BACKGROUND

Catheter-associated urinary tract infection (CAUTI) is a common clinic problem. The purpose of this study was to investigate recent trends in CAUTI in neurogenic bladder patients focusing on extended-spectrum β-lactamase (ESBL)-producing Escherichia coli.

METHODS

Isolates from the urine of neurogenic bladder patients with UTI were investigated. Nine strains of ESBL-producing E coli were assayed by molecular strain typing using the Diversilab system for repetitive-sequence-based polymerase chain reaction (rep-PCR).

RESULTS

E coli accounted for most of the bacteria (74.1% to 81.0%) that produced ESBLs. Rep-PCR data showed that 7 out of 9 ESBL-producing E coli belonged to the same typing group with high similarity (more than 97% similarity) and that this distribution corresponded with antibiotic resistance patterns.

CONCLUSION

ESBL producing E coli strains isolated from CAUTI patients could be discriminated by rep-PCR typing using the Diversilab system in consistent with antibiotic resistance patterns.

[Randomized comparative study for the assessment of a new therapeutic schedule of fosfomycin trometamol in postmenopausal women with uncomplicated lower urinary tract infection]

OBJECTIVES

To compare two therapeutic regimes in terms of bacterial eradication of post-menopausal with uncomplicated acute cystitis who complete antibiotic treatment.

MATERIALS AND METHOD

A multicenter, randomized, prospective and controlled study between two short antibiotic regimes: fosfomycin trometamol (FMT) 3g, 2 doses separated by 72hours and ciprofloxacin 250mg every 12hours for 3 days. A total of 118 post-menopausal women were enrolled in the study. They underwent an initial urine culture to know the responsible microorganism and susceptibility to treatment. This was repeated 5-7 days and 4 weeks after the treatment to evaluate bacterial eradication. Clinical symptoms and treatment safety were also evaluated.

RESULTS

There were microbiological data at the onset of the treatment in 82 women (69.49%). Of these, 27 did not have positive culture at the first visit (30.51%), 76 (64.41%) fulfilled all the protocol requirements and adverse effects from the treatment were collected in 113 (95.76%) of the patients enrolled in the study. The germs isolated most frequently were Escherichia coli (E. coli) (76.83%), Klebsiella pneumoniae (K. pneumoniae) (7.32%), Proteus mirabilis (P. mirabilis) (4.89%) and Enterococo sp. (3.66%). In terms of efficacy, no differences were detected in the proportion of patients who achieved bacterial eradication between the two study arms: 62.16% of the patients who received FMT and 58.97% of those treated with ciprofloxacin (chi-square, p=0.78). The proportion of patients who achieved clinical cure was also similar (86.49% for FMT and 82.05% for ciprofloxacin; square, p=0.59). These results indicate similar efficacy of both antibiotics in the treatment of uncomplicated lower tract urinary infection in post-menopausal women. In regards to safety data, the proportion of global adverse effects associated to the treatments was 3.45% for FMT and 9.09% for ciprofloxacin. Treatment compliance was 100% for FMT and 83.64% for ciprofloxacin.

CONCLUSIONS

The FMT administered at a dose of 3g every 72hours (2 total doses) and ciprofloxacin at a dose of 250mg every 12hours during 3 days (6 total doses) have a comparable efficacy profile in lower tract urinary infection in post-menopausal women who adequately comply with the treatment, also having comparable safety. The FMT has a better antimicrobial susceptibility profile and better rate of treatment compliance.

[Urinary infection in patients with neurogenic bladder: patterns of resistance to the most frequent uropathogens]

PURPOSE

To analyze the most frequent causes and resistances of the uropathogens in patients affected by neurogenic bladder.

MATERIAL AND METHODS

A total of 284 patients, in whom a total of 284 urinary cultures were performed, were included. Of these, 106 came from patients with neurological injuries, 28 from a non-neurogenic control group, 75 from patients admitted to the intensive care unit (ICU) of our Hospital and 75 patients who came into the emergency room with the symptoms of an acute urinary tract infection. A quantitative urine culture was performed in a chromogenic media and the resistances of all urine cultures that were positive for one or two micro-organisms were identified and studied.

RESULTS

A total of 67% of the patients with neurological injuries had positive urine cultures compared to 25% of control group patients. The urine cultures of patients admitted into the ICU and those of the Emergency Room group were 100% positive, since the first 75 positive urine cultures were selected for the study. E.coli was the most-frequently microorganism isolated in the group of neurological patients, as well as among the patients from the Emergency Room and from the control group. In the ICU, the most-frequently isolated micro-organism was Enterococcus spp. (19.4%), followed by P. aeruginosa (16.5%). The study of resistances in general E. coli has high rates of resistance to ampicillin and co-trimoxazole and, although to a lesser degree to ciprofloxacin.

CONCLUSIONS

E. coli is the micro-organism most frequently isolated among all of the groups except in the ICU, where it is surpassed by Enterococcus spp. and P. aeruginosa. The resistances among the four population groups studied have different features, overall showing a low rate of resistance to nitrofurantoin and especially to fosfomycin, observed in patients from the Emergency Room or admitted to the ICU and neurological patients.

Epidemiology, risk factors and comorbidity for urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing enterobacteria

AIM

Urinary tract infection (UTI) caused by resistant bacteria is becoming more prevalent. We investigate characteristics and associated risk factors for UTIs resulting from extended-spectrum beta-lactamase (ESBL)-producing enterobacteria.

METHODS

Retrospective study of urinary tract isolates of ESBL-producing enterobacteria in adults (2009 and 2010). We included 400 patients and 103 controls (UTI caused by non-ESBL Escherichia coli). Clinical and demographic information was obtained from medical records. Comorbidity was evaluated using Charlson Index (CI). Strains were identified using VITEK 2 system.

RESULTS

A total of 400 isolates were obtained (93%E. coli and 7%Klebsiella spp). In 2009, 6% of cultures were ESBL-producing E. coli and 7% in 2010. 37% of patients were men and 81% were aged ≥60years. CI was 2.3±1.8 (high comorbidity: 42.8%). 41.5% of strains were susceptible to amoxicillin-clavulanate, 85.8% to fosfomycin and 15.5% to ciprofloxacin. The total number of ESBL E. coli positive urine cultures during hospital admission was 97 and, compared with 103 controls, risk factors for UTI caused by ESBL- E. coli strains in hospitalised patients were nursing home residence (p<0.001), diabetes (p=0.032), recurrent UTI (p=0.032) and high comorbidity (p=0.002). In addition, these infections were associated with more symptoms (p<0.001) and longer admission (p=0.004).

CONCLUSIONS

Urinary tract infection caused by ESBL are a serious problem and identifying risk factors facilitates early detection and improved prognosis. Male sex, hospitalisation, institutionalisation, diabetes, recurrent UTI and comorbidity were risk factors and were associated with more symptoms and longer hospital stay.

Extended-spectrum β-lactamase-producing Enterobacteriaceae: in vitro susceptibility to fosfomycin, nitrofurantoin and tigecycline

OBJECTIVE

To assess the susceptibility trends of community-acquired extended-spectrum β-Iactamase (ESBL)-producing urinary isolates with particular reference to fosfomycin, nitrofurantoin and tigecycline.

MATERIALS AND METHODS

Seven hospitals across the United Arab Emirates participated in this study from June 2008 to March 2010. The antibiotic sensitivity of ESBL-producing uropathogens to a panel of antibiotics including tigecycline, fosfomycin and nitrofurantoin was assessed. The Hyplex ESBL identification system (h-ES-ID) was used for genotypic identification.

RESULTS

Two hundred and ninety-two ESBL-producing Enterobacteriaceae isolates were identified during the study period. Of these, 182 (62%) were urinary isolates and comprised of Escherichia coli: 149 (81.9%), Klebsiella pneumoniae: 30 (16.5%) and Proteus mirabilis: 3 (1.6%). Of the 182 urinary isolates, 179 (98.3%) were from patients with community onset urinary tract infections. The h-ES-ID system identified 172 (94.5%) of the urinary isolates as CTX-M positive. All isolates were susceptible to imipenem and meropenem. Over half of the isolates showed resistance to gentamicin (98; 53.8%), trimethoprim-sulfamethoxazole (139; 76.4%) and ciprofloxacin (143; 78.6%). Sensitivity to nitrofurantoin and fosfomycin was 90 and 100%, respectively. Two CTX-M-positive K. pneumoniae isolates with tigecycline resistance (MIC >4 µg/ml) were identified.

CONCLUSION

There is dissemination of CTX-M ESBL-producing urinary pathogens into the community. Fosfomycin and nitrofurantoin were active against ESBL-positive uropathogens, and emergence of tigecycline resistance needs close monitoring.

The revival of fosfomycin

Fosfomycin, originally named phosphonomycin, was discovered in Spain in 1969. There are three forms of fosfomycin: fosfomycin tromethamine (a soluble salt) and fosfomycin calcium for oral use, and fosfomycin disodium for intravenous use. Fosfomycin is a bactericidal antibiotic that interferes with cell wall synthesis in both Gram-positive and Gram-negative bacteria by inhibiting the initial step involving phosphoenolpyruvate synthetase. It has a broad spectrum of activity against a wide range of Gram-positive and Gram-negative bacteria. It is highly active against Gram-positive pathogens such as Staphylococcus aureus and Enterococcus, and against Gram-negative bacteria such as Pseudomonas aeruginosa and Klebsiella pneumoniae. Its unique mechanism of action may provide a synergistic effect to other classes of antibiotics including beta-lactams, aminoglycosides, and fluoroquinolones. Oral fosfomycin is mainly used in the treatment of urinary tract infections, particularly those caused by Escherichia coli and Enterococcus faecalis. Intravenous fosfomycin has been administered in combination with other antibiotics for the treatment of nosocomial infections due to multidrug-resistant (MDR) Gram-positive and Gram-negative bacteria. Fosfomycin has good distribution into tissues, achieving clinically relevant concentrations in serum, kidneys, bladder wall, prostate, lungs, inflamed tissues, bone, cerebrospinal fluid, abscess fluid, and heart valves. Fosfomycin is well tolerated, with a low incidence of adverse events. Further randomized controlled trials are needed in order to evaluate the efficacy of intravenous fosfomycin for the management of nosocomial infections due to MDR pathogens.

Oral treatment options for ambulatory patients with urinary tract infections caused by extended-spectrum-beta-lactamase-producing Escherichia coli

An increase in extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli has been observed in outpatient settings. Consequently, 100 ESBL-positive E. coli isolates from ambulatory patients with clinically confirmed urinary tract infections were collected by a single laboratory between October 2004 and January 2008. Antimicrobial susceptibility testing was carried out using the oral antibiotics fosfomycin, pivmecillinam, and nitrofurantoin and the parenteral antibiotic ertapenem. Susceptibility rates indicate that fosfomycin (97%), nitrofurantoin (94%), and pivmecillinam (85%) could be considered important oral treatment options.

[Qnr-type quinolone resistance in extended-spectrum beta-lactamase producing enterobacteria in Abidjan, Ivory Coast]

The aim of the study was to show the emergence of the qnr genes in extended spectrum beta-lactamases producing enterobacteria in Abidjan between 2005 and 2006. The whole of 151 strains of extended spectrum beta-lactamases producing enterobacteria were studied: 64 Escherichia coli, 66 Klebsiella pneumoniae, seven Klebsiella oxytoca and 14 Enterobacter spp. isolated from various biological products and from in- and out-patients. The techniques of disks diffusion, double-disk synergy, E-test were respectively used for the antimicrobial susceptibility test, the detection of extended spectrum beta-lactamases and the minimal inhibiting concentration. The bla genes(SHV, TEM, CTXM groups 1, 2, 8, 9), and AmpC were determined by PCR and characterized by sequencing. A global prevalence of 27,2 % (41/151) and rates of 9,9, 14,6, 2,7 % for the qnr genes A, B, A and S were observed. The distribution was 42,9 % for Enterobacter spp, 31,2 % for Escherichia coli, 20,5 % for Klebsiella; 30 strains expressed at least two bla genes; four strains were associated with AmpC. The strains were resistant to the cotrimoxazole (97,6 %), to the céfépime (73,2 %), to the céfoxitine (56,1 %), to the imipénème (0 %) and 43,9 % to all the aminosides. This high qnr gene prevalence associated with several types of bla genes in epidemic matter, the high level of resistance to antibiotics make fear a high risk of the transmission of multi-resistants bacteria and challenge the authorities for a resistance monitoring policy.

[Etiology of community-acquired lower urinary infections and antimicrobial resistance of Escherichia coli: a national surveillance study]

BACKGROUND AND OBJECTIVES

The increasing rates of resistance exhibited by uropathogens represent a serious problem. The aim of this study was to determine, in Spain, the etiology of community-acquired lower urinary infections and antimicrobial resistance of Escherichia coli isolates.

METHODS

Prospective multicenter study conducted between February and June 2006, in 15 microbiology laboratories located in 9 autonomous regions.

RESULTS

A total of 3,109 isolates were recovered. E. coli was the most frequent (70.8%), followed by Klebsiella spp (6.8%) Proteus spp (6.6%), and Enterococcus spp (5.5%). The resistant rate of E. coli for phosphomycin was 1.7%, 3.8% nitrofurantoin, 6.9% cefexime, 8.1% amoxicillin-clavulanic, 8.9% cefuroxime, and 23.9% ciprofloxacin. The 5.2% were extended-spectrum beta-lactamase (ESBL)- producing microorganisms. Resistance of E. coli to ciprofloxacin was lower in people younger than 40 years (6.7% vs 33.9% in > 60, p < 0.001), and in some regions (12.5% in Galicia vs 37.3% in Valencia). ESBL-producing E.coli was higher in people older than 60 years (79.1% vs 7% in < 40, p < 0.001), and exhibited geographic variations (18.4% in Valencia, 0.8% in Galicia). The 68.6% of ESBL-producing E.coli were resistant to cotrimoxazole, 72.2% to ciprofloxacin vs 10.6% to nitrofurantoin and 1.9% to phosphomycin.

CONCLUSIONS

The increasing rates of resistance and cross-resistance of this study make evident a real problem that strengthens the need for a reevaluation of the empiric treatment of lower urinary infections.