[Is stratification of antibiotic susceptibility of urinary pathogens useful in the Emergency Department?] / ¿Es útil la estratificación de la sensibilidad antibiótica de los patógenos urinarios en el Servicio de Urgencias?

OBJECTIVE: The aim of the study wat to analyze the antibiotic susceptibility of the pathogens causing urinary tract infection (UTI) and to stratify the results in function of patient´s clinical and demographic dates. METHODS: The susceptibility of the pathogens isolated in the urine of 144 patients with UTI randomly chosen was analyzed. The results were stratified in function of sex, age, type of UTI, previous UTI and previous antibiotic treatment. RESULTS: The susceptibility of the all isolates and of the Escherichia coli isolates was analyzed. There were significant differences between groups in function of sex (fluoroquinolones), age (cefuroxime, ertapenem and gentamicin), type of UTI (cefuroxime, cefotaxime, ertapenem and fluoroquinolones), previous UTI and previous antibiotic treatment (cefotaxime, fluoroquinolones and fosfomycin). CONCLUSIONS: The use of clinical and demographic data according to population and local resistance epidemiology of the pathogen causing UTI may help to select an adequate empirical treatment for UTI.

Is it possible to extrapolate the rates of resistance of Escherichia coli from asymptomatic bacteriuria in pregnant women to those of E. coli in uncomplicated community-acquired UTI?

OBJECTIVE: Treatment of uncomplicated urinary tract infections in primary care is generally empirical without requesting urine culture and based on biased resistance data collected from selected patients, most of them having risk factors for the isolation of resistant microorganisms. In order to overcome the lack of information on the real resistance rates in uncomplicated UTI, we compared antimicrobial phenotype and genotype of Escherichia coli isolated from pregnant women with asymptomatic bacteriuria (culture always performed) with those from women with uncomplicated acute cystitis (culture rarely performed) of different age groups. METHODS: Between September 2017 and March 2018, 103 urines were randomly collected from pregnant women aged between 16 and 47 with asymptomatic bacteriuria (AB) (n=42), not hospitalized women in the same age range with uncomplicated acute cystitis (UAC) (n=31) and women older than 47 not hospitalized with UAC (n=30). Bacteria identification was performed using mass spectrometry and the antibiogram by broth microdilution. Genetic typification was carried out by pulsed-field gel electrophoresis. RESULTS: There are no significant differences between the groups of patients in the antibiotic susceptibility. Likewise, as expected, a wide genetic diversity is observed among the strains of E. coli studied without significant differences between the three groups. CONCLUSIONS: We propose a simple model that could provide better guidance for selection of empirical antimicrobial therapy for non-pregnant women with UAC than do generic hospital antibiogram data based on reliably extrapolating the susceptibility data of strains isolated from pregnant women with AB as representation of women with community-acquired UAC.

[Biological cost associated with fosfomycin resistance in Escherichia coli isolates from urinary tract infections]. / Coste biológico asociado a la resistencia a la fosfomicina en aislamientos de Escherichia coli de orina.

Resistance to fosfomycin develops rapidly in experimental conditions, although despite its frequent use in UTI, resistance in E. coli, the main uropathogen, is very low (1-3%), and has remained so for many years. The objective of this study was to ascertain whether E. coli fosfomycin-resistant strains have less fitness than those that are fosfomycin-sensitive in competing, and would therefore tend to disappear in their competition with fosfomycin-sensitive strains in the absence of antibiotics. Fosfomycin-resistant strains (n=11) with different phenotypes of resistance to other antibiotics were used. All but one were lactose (+). Fosfomycin-susceptible strains (n=15) that had the same phenotypes of resistance to other antibiotics as the resistant strains and which had the opposite pattern of lactose fermentation were also used. Thirty-three (33) competition experiments by pairs of strains were conducted in nutrient broth. Equal amounts of the strains were challenged (approx. 50% and approx. 50%) for 4 days, with a daily change to a new medium. Five differential counts were performed on days 0, 1, 2, 3 and 4. In 20 experiments (60.6%) there was a relative increase in the fosfomycin-sensitive strain. In 6 experiments (18.2%) there was a relative increase in the fosfomycin-resistant strain. In 7 experiments (21.2%), on the fourth day none of the strains reached 60%. When the data of the 26 (20+6) experiments in which there were changes were analyzed by the chi2 test there was a statistically significant difference (p=0.044). Resistance to fosfomycin could entail a biological cost (less fitness) for the majority of the E. coli strains assayed.

Quinolone resistance in female outpatient urinary tract isolates of Escherichia coli: age-related differences.

During a 1-year period, from November 2003 to October 2004, urinary Escherichia coli isolates were collected from 20 clinical microbiology laboratories across Spain. The main objective was to assess the resistance of E. coli to the antimicrobials most commonly prescribed for community-acquired urinary tract infections depending on the patient's age. A total of 2,230 valid E. coli strains from female outpatients were isolated and sent to a single central reference laboratory for confirmation and susceptibility testing using an agar dilution method. A two-sided chi-squared test was used to assess the differences in resistance between age groups (< or =65 and >65 years). E. coli resistance was found to be more common to ampicillin (52.1%), cotrimoxazole (26%) and quinolones (18%), whereas resistance to amoxicillin-clavulanic acid, cefuroxime axetil and fosfomycin were below 3%. In women older than 65 years, resistance to ciprofloxacin reached up to 29% compared with 13% of those in the under 65 age group (p <0.001). For cotrimozaxole, rates were 32% vs. 23% (p <0.001) and for ampicillin 56% vs. 50% (p=0.02), respectively. It was concluded that fosfomycin, amoxicillin-clavulanic acid and cefuroxime axetil are the most suitable antimicrobials for empirical treatment in Spain given the high 18% and 26% resistance rates to quinolones and cotrimoxazole, respectively. Being older than 65 years of age was associated with higher resistance rates to ciprofloxacin (29%). These results should be considered when recommending empirical therapy for acute cystitis in women.

Activity of ertapenem and other antimicrobials against ESBL-producing enterobacteria isolated from urine in patients from Madrid.

The objective of this study was to evaluate the activity of ertapenem and other antimicrobials against extended-spectrum beta-lactamase (ESBL)-producing enterobacteria isolated from patients' urine samples at 4 community healthcare centers in the Madrid (Spain) area and to determine the prevalence of ESBL-producing enterobacteria in community-acquired urinary tract infections. The antibiotic susceptibility results were compared by patient age and sex. A total of 293 strains were studied. The minimum inhibitory concentration (MIC) for each antibiotic was determined using the agar dilution method. The tested carbapenems were the antibiotics with the greatest activity (ertapenem MIC(90)=0.06 mg/l; imipenem MIC(90)=0.5 mg/l), with no intermediate or resistant strains being observed. High rates of resistance to ciprofloxacin (80.9%) and cotrimoxazole were observed (62.1%). The global prevalence of ESBL-producing enterobacteria was 3.6% (293/8,139). Prevalence according to areas was 5.3% in Getafe, 3.45% in Arguelles, 3.02% in Alcala de Henares and 3.56% in Mostoles. The global prevalence of ESBL-producing Escherichia coli was 4.15% (279/6,721). The analysis of resistance according to patient sex (males versus females) showed no significant differences. The analysis of resistance according to patient age (<50 years versus > or = 50 years) showed statistically significant differences (more resistance among subjects > or = 50 years old) for cotrimoxazole (OR=0.43, 95%CI: 0.20-0.93, p=0.018) and ciprofloxacin (OR=0.32, 95%CI: 0.14-0.74, p=0.0027). In view of the good activity shown by ertapenem, and the continuous increase in the prevalence of ESBL strains, this antibiotic and some of the others could be a good choice for the treatment of community-acquired urinary tract infections produced by such bacteria in Spain.

Antimicrobial susceptibility of clinical Escherichia coli isolates from uncomplicated cystitis in women over a 1-year period in Spain.

High usage of antibiotics in Spain has led to an increase in resistance in urinary Escherichia coli isolates in different geographic regions. The problem of resistance in urinary E. coli in Spain was investigated by gathering a large number of isolates from 20 different sites nationwide over a 1-year period from November 2003 to October 2004 in a large population of women. The objectives of this study were to assess the resistance to the antibiotics most commonly prescribed for community-acquired urinary tract infections (UTIs), according to age and different geographical areas of Spain, and to evaluate the potential association between geographical differences in quinolone consumption and resistance to E. coli. A total of 2,292 valid E. coli strains from female outpatients were isolated and sent to a single central reference laboratory for confirmation and susceptibility testing. Of these, 2,230 isolates were available for the age analysis. A two-sided chi2 test was used to identify differences in resistance between age groups. Antibiotic units per province were purchased from IMS and consumption was expressed in units per 1,000 people per year. Univariate correlation (Pearson coefficient) between resistance to ciprofloxacin and quinolone consumption was calculated using a two-sided p-value. Resistance shown by E. coli was more common to ampicillin (52.1%) and cotrimoxazole (26%), followed by quinolones (18%), whereas resistance to amoxicillin-clavulanic acid, cefuroxime-axetil and fosfomycin was less than 3%. In the subgroup of women aged >65 years, resistance to ciprofloxacin was 29% compared to 13% for the subgroup of women <65 years (p<0.001). For these same subgroups, resistance rates were 32% vs. 23% for cotrimoxazole (p<0.001) and 56% vs. 50% for ampicillin (p=0.02), respectively. Statistically significant correlations were found between consumption of quinolones and E. coli resistance to ciprofloxacin (r=0.5; p=0.025). Resistance of E. coli isolates to quinolones varied significantly according to geographical areas, ranging from a high of 16.5% and 16.6% in the southern and eastern regions of Spain, respectively, to a low of 8% in the north in women aged <65 years. Additionally, the susceptibility to quinolones of E. coli isolates recovered from women aged >65 years was significantly lower across all regions of Spain than that of isolates recovered from younger women. Fosfomycin, amoxicillin/clavulanic acid and cefuroxime-axetil are the most suitable antibiotics for empirical treatment in Spain given the high 18% and 26% resistance rates to quinolones and cotrimoxazole, respectively. Higher resistance rates to ciprofloxacin were associated with being aged 65 years and over. These data need to be considered when recommending empirical therapy for acute cystitis.

Antibiotic resistance of Escherichia coli from community-acquired urinary tract infections in relation to demographic and clinical data.

This prospective study determined the antibiotic susceptibility of 164 isolates of Escherichia coli from the urine of 164 patients (112 female, 52 male; mean age of 54.12 years) with community-acquired urinary tract infection (UTI). Half of the isolates were from uncomplicated UTI and half from complicated UTI (52 males and 34 females). Overall, 57.3% of isolates were resistant to ampicillin, 25% to co-trimoxazole, 20.1% to nalidixic acid, 14% to norfloxacin and ciprofloxacin, and 0% to fosfomycin and nitrofurantoin. Of the 82 isolates from complicated UTI, 16 (19.5%) were resistant to norfloxacin and ciprofloxacin, compared with seven (8.5%) from uncomplicated UTI (p 0.043). Isolates from patients aged >50 years were significantly more resistant than those from patients aged <50 years for nalidixic acid (p 0.007) and the fluoroquinolones tested (p 0.015). Resistance to fluoroquinolones was 25% (13/52) in males and 9% (10/112) in females (p 0.006). For patients with and without previous antimicrobial therapy, there was a significant difference only for resistance to nalidixic acid (p < 0.001) and the fluoroquinolones (p 0.011). There were adequate susceptibility rates to fosfomycin, nitrofurantoin and the fluoroquinolones for empirical use in the treatment of acute uncomplicated UTI. In order to interpret cumulative susceptibility data from the primary healthcare setting, it is necessary to take into account the type of UTI (uncomplicated vs. complicated), previous antimicrobial therapy, and the sex and age of each patient.

[Guidelines for the management of community pneumonia in adult who needs hospitalization]. / Guías para el manejo de la neumonía comunitaria del adulto que precisa ingreso en el hospital.

Community acquired pneumonia is still an important health problem. In Spain the year incidence is 162 cases per 100,000 inhabitants with 53,000 hospital admission costing 115 millions of euros per year. In the last years there have been significant advances in the knowledge of: aetiology, diagnostic tools, treatment alternatives and antibiotic resistance. The Spanish Societies of Intensive and Critical Care (SEMICYUC), Infectious Diseases and Clinical Microbiology (SEIMC) and Pulmonology and Thoracic Surgery (SEPAR) have produced these evidence-based Guidelines for the management of community acquired pneumonia in Adults. The main objective is to help physicians to make decisions about this disease. The different points that have been developed are: aetiology, diagnosis, treatment and prevention.

Concurrent interspecies and clonal dissemination of OXA-48 carbapenemase.

Several isolates of four different carbapenemase-producing Enterobacteriaceae species were recovered from a patient hospitalized for 4 months in a teaching hospital in Madrid. These species comprised seven Klebsiella pneumoniae belonging to ST15, four Escherichia coli belonging to ST2531, two Serratia marcescens and one Citrobacter freundii. This patient was the index case of a small outbreak of four patients infected and/or colonized by carbapenemase-producing K. pneumoniae. Molecular results identified the bla(OXA-48) gene in all Enterobacteriaceae isolates from the index case and in all isolates from the other three patients, suggesting intra- and interpatient dissemination. Our results highlight the great ability of OXA-48 carbapenemase to spread among different enterobacterial species by both clonal and nonclonal dissemination.

Bacteriologic characteristics and antimicrobial susceptibility of 70 clinically significant isolates of Streptococcus milleri group.

The phenotypical characteristics of 70 clinical isolates of Streptococcus milleri group were analyzed. Association of the three species with particular sites of isolation could not be demonstrated in all cases, but S. anginosus strains predominated in abdominal area, while S. intermedius was isolated mainly in hepatic abscesses. Penicillin G and other beta-lactams showed good in vitro activity against these streptococci, whereas > 10% exhibited resistance to erythromycin and clindamycin. Resistance to tetracycline reached almost 40%. All of the isolates were uniformly susceptible to vancomycin, chloramphenicol, and trimethoprim.

Nosocomial bacteremia and catheter infection by Bacillus cereus in an immunocompetent patient.

We present a case of Bacillus cereus bacteremia and catheter infection in an immunocompetent patient subjected to abdominal surgery, who recovered following central catheter removal and treatment with piperacillin/tazobactam.

Acute and chronic otitis media and Turicella otitidis: a controversial association.

Turicella otitidis is a non-fermenting Gram-positive bacillus isolated almost exclusively from ear exudates. Its significance in acute or chronic otitis media is controversial. Over a 12-month period, T. otitidis was isolated from nine ear exudates from seven patients. Most of these were cases of spontaneous drainage following recurrence of otitis media after antimicrobial therapy that was ineffective against T. otitidis. The MICs of penicillin, levofloxacin, linezolid and vancomycin were very low for all the isolates studied, but most isolates displayed high resistance to macrolides and lincosamides.

[High incidence of ampicillin resistance in Salmonella spp non typhi]. / Alta frecuencia de elevada resistencia a ampicilina en Salmonella spp no typhi.

Salmonella spp non typhi is a common cause of gastroenteritis and, more rarely, extraintestinal infections in humans. The type of syndrome determines the choice and duration of antibiotic therapy. Extraintestinal infections by this organism require correct antibiotic therapy. In the present study, the susceptibility to antibiotics of 59 strains of Salmonella spp non typhi from clinical sources, isolated during a period of three and a half months, were evaluated. Fifty one of them were S. enteritidis, 7 S. typhimurium and 1 S. schwarzengrund. A high frequency (45.8%) of resistance to ampicillin (MIC greater than 256 micrograms/ml) was found. Other antibiotics had good or excellent in vitro activity: 90% of strains were sensitive to tetracyclines, 93% to chloramphenicol, 97% to co-trimoxazole, and 100% to cefotaxime and ciprofloxacine. It was concluded that the high frequency of ampicillin resistance to ampicillin precludes its use as first choice antibiotic in our area for suspected extraintestinal infections caused by Salmonella spp non typhi.

[Antibiotic sensitivity of strains of group A beta-hemolytic streptococci isolated recently]. / Sensibilidad a los antibióticos de cepas de estreptococo beta-hemolítico del grupo A aisladas recientemente.

The present study investigated the sensitivity of 35 group A beta-hemolytic streptococci strains, isolated from clinical samples in 1988 and 1989, to 12 antibiotics. The minimal inhibitory concentrations of each antibiotic were measured by the agar dilution method. All strains were sensitive to penicillin G, ampicillin, oxacillin, cefazolin, cefotaxime, erythromycin, clindamycin, vancomycin and ciprofloxacin. It was concluded that, in our area, Streptococcus pyogenes still has an excellent sensitivity to penicillin G and to other antibiotics which may be a therapeutic alternative in allergic patients or an empiric treatment in infections likely to be produced, among other organisms, by S. pyogenes.

[The prevalence of Escherichia coli susceptibility to quinolones and other antibiotics in community-acquired bacteriurias in Madrid]. / Prevalencia de susceptibilidad de Escherichia coli a quinolonas y otros antibióticos en bacteriurias extrahospitalarias de Madrid.

BACKGROUND: The empiric treatment of extrahospitalary urinary infections must keep in mind the patterns of susceptibility of the potentially causative bacteria. The consumption of antibiotics is one of the most important causes of change in the susceptibility of the bacteria. The recent introduction of fluorquinolones and the widespread use of those antibiotics makes knowledge of new patterns of sensitivity necessary in order to determine whether there are changing sensitive pattern among the different geographic zones. METHODS: During a period of two weeks randomly chosen 379 strains of Escherichia coli isolated from extrahospitalary bacteria were collected in 11 laboratories in 4 health areas in Madrid. Sensitivity to 11 antibiotics, including four of the quinolone group was determined by the agar dilution method. The existence of significant differences of sensitivity among the different areas was analyzed by the chi 2 test. RESULTS: The prevalence of sensitivity to ampicillin and cotrimoxazol was 42 and 73% respectively. Nineteen percent of the strains were resistant to amoxycillin/clavulanic acid. No strain was found to be resistant to cefotaxime. Four percent of the sample studied was not sensitive to the new fluorquinolones and almost 10% were resistant to nalidixic acid latter having decreased sensitivity to the fluorquinolones. No significant differences were observed in sensitivity among the areas, except with amoxycillin/clavulanic acid and cotrimoxazole. CONCLUSIONS: The high prevalence of the resistance of E. coli to ampicillin recently leads to the recommendation of its use in empiric treatments of urinary infections. In the zone in Madrid studied a high prevalence of resistance and decreased sensitivity of E. coli to fluoroquinolones was observed. It is therefore advisable to moderate their use to thereby prolong use over time.