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B Mirelis

Publications and source records attributed to B Mirelis.

At least 19 recordsLinked to original sources
PubMed2005

Characterisation of fluoroquinolone-resistant clinical isolates of Streptococcus pyogenes in Barcelona, Spain.

Resistance mechanisms and clonal relationships were determined for six Streptococcus pyogenes isolates with low- or high-level ciprofloxacin resistance. Four isolates displayed reduced susceptibility to ciprofloxacin and levofloxacin and had alterations in ParC: Ser80-->Pro (isolate emm3.1); Ser79-->Ala (two isolates emm6.0); and a double substitution Ser79-->Phe and Ala121-->Val (isolate emm12.27). Two isolates (emm12.26) displayed high-level resistance to ciprofloxacin and levofloxacin, as well as to other quinolones. These isolates had the same double substitution in ParC as isolate emm12.27, and an additional substitution (Ser81-->Tyr) in GyrA. Resistance patterns, emm typing and sequencing of the quinolone resistance-determining regions defined two clusters containing three and two isolates, respectively.

Amino Acid Substitution↗
PubMed2001

CMY-2-producing Salmonella enterica, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis and Escherichia coli strains isolated in Spain (October 1999-December 2000).

CMY-2 plasmid-mediated AmpC beta-lactamase (CMY-2) was detected in 21 isolates from two hospitals located in different geographical regions of Spain between October 1999 and December 2000. The isolates comprised two Salmonella enterica serovars (Mikawasima and Montevideo), 16 Escherichia coli, one Klebsiella pneumoniae, one Klebsiella oxytoca and one Proteus mirabilis. In addition to the expected resistance to beta-lactams, including extended-spectrum cephalosporins and cefoxitin, all isolates showed a broad spectrum of associated resistance. All were resistant to sulfamethoxazole, chloramphenicol, tetracycline and streptomycin, and all but two were also resistant to gentamicin. Five isolates were studied in detail and all transferred CMY-2 and other resistance determinants by conjugation. Genomic DNA restriction pattern analysis of the E. coli isolates excluded the dissemination of a single clone. To the best of our knowledge this is the first time that CMY-2 has been detected in P. mirabilis, K. oxytoca and S. enterica serovars Mikawasima and Montevideo. It is also the first time that CMY-2 has been described in Spain.

Anti-Bacterial Agents↗
PubMed2000

Antibiotic resistance trends in enteropathogenic bacteria isolated in 1985-1987 and 1995-1998 in Barcelona.

Trends in resistance to antimicrobial agents used for therapy have been evaluated with 3,797 enteropathogenic bacteria, Campylobacter, Salmonella, Shigella, and Yersinia, between 1985-1987 and 1995-1998. The greater increase in the rate of resistance was observed in Campylobacter jejuni for quinolones (from 1 to 82%) and tetracycline (from 23 to 72%) and in gastroenteric salmonellae for ampicillin (from 8 to 44%), chloramphenicol (from 1.7 to 26%), and trimethoprim-sulfamethoxazole and nalidixic acid (from less than 0.5 to 11%). Multidrug resistance was detected in several Salmonella serotypes. In the 1995-1998 period, 76% of Shigella strains were resistant to trimethoprim-sulfamethoxazole, 43% were resistant to ampicillin, and 39% were resistant to chloramphenicol. Seventy-two percent of Yersinia enterocolitica O3 strains were resistant to streptomycin, 45% were resistant to sulfonamides, 28% were resistant to trimethoprim-sulfamethoxazole, and 20% were resistant to chloramphenicol.

Campylobacter↗
PubMed2000

Escherichia coli serotype O15:K52:H1 as a uropathogenic clone.

To clarify the clinical and bacteriological correlates of urinary-tract infection (UTI) due to Escherichia coli O15:K52:H1, during a 1-year surveillance period we prospectively screened all 1, 871 significant E. coli urine isolates at the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain, for this serotype and assessed the epidemiological features of community-acquired UTI due to E. coli O15:K52:H1 versus other E. coli serotypes. We also compared the 25 O15:K52:H1 UTI isolates from the present study with 22 O15:K52:H1 isolates from other, diverse geographic locales and with 23 standard control strains (8 strains from the ECOR reference collection and 15 strains of nonpathogenic O:K:H serotypes) with respect to multiple phenotypic and genotypic traits. Although E. coli O15:K52:H1 caused only 1.4% of community-acquired E. coli UTIs during the surveillance period, these UTIs were more likely to present as pyelonephritis and to occur in younger hosts, with similar risk factors, than were UTIs due to other E. coli serotypes. Irrespective of geographic origin, E. coli O15:K52:H1 strains exhibited a comparatively restricted repertoire of distinctive virulence factor profiles (typically, they were positive for papG allele II, papA allele F16, and aer and negative for sfa, afa, hly, and cnf1), biotypes, ribotypes, and amplotypes, consistent with a common clonal origin. In contrast, their antimicrobial resistance profiles were more extensive and more diverse than those of control strains. These findings indicate that E. coli O15:K52:H1 constitutes a broadly distributed and clinically significant uropathogenic clone with fluid antimicrobial resistance capabilities.

Bacteremia↗
PubMed2000

Salmonella enterica serovar virchow with CTX-M-like beta-lactamase in Spain.

Four Salmonella enterica serovar Virchow strains resistant to broad-spectrum cephalosporins were isolated from patients with gastroenteritis in 1997 and 1998 in Murcia and Barcelona, Spain. The isolates expressed a beta-lactamase with a pI of about 8 and a positive PCR when specific primers for CTX-M-9 were used. These results suggest the presence of a CTX-M-9 beta-lactamase in these strains.

Drug Resistance, Microbial↗
PubMed1999

[Haemophilus influenzae type b invasive disease in Catalonia (1996)].

BACKGROUND: The purpose of this study was to find out the incidence and characteristics of H. influenzae type b invasive disease (HibID) in Catalonia, Spain. MATERIAL AND METHODS: An active surveillance of H. influenzae isolated from normally sterile sites was carried out during 1996. Microbiology laboratories of hospitals of Catalonia were periodically contacted by telephone. The serotype of all the strains was studied. RESULTS: The incidence of H. influenzae invasive disease (HIID) was 7.1 per 100,000 in children under 5 years and 1.0 per 100,000 in those over 5 years. The incidence of serotype b was 6.4 per 100,000 children under 5 years and 0.2 above this age. Only three strains belonged to types other than b (d, e and f). CONCLUSIONS: The incidence of HIbID is uncommon in Catalonia, lower than that registered in the prevaccine era in other countries and regions of the same geographical area.

Adolescent↗
PubMed1999

Infections caused by Escherichia coli resistant to norfloxacin in hospitalized cirrhotic patients.

Selective intestinal decontamination with norfloxacin is useful to prevent bacterial infections in several groups of cirrhotic patients at high risk of infection. However, the emergence of infections caused by Escherichia coli resistant to quinolones has recently been observed in cirrhotic patients undergoing prophylactic norfloxacin. Our aim is to determine the characteristics of the infections caused by E. coli resistant to norfloxacin in hospitalized cirrhotic patients. One hundred and six infections caused by E. coli in 99 hospitalized cirrhotic patients were analyzed and distributed into two groups: group I (n = 67), infections caused by E. coli sensitive to norfloxacin, and group II (n = 39), infections caused by E. coli resistant to norfloxacin. The clinical and analytical characteristics at diagnosis of the infection were similar in both groups. Previous prophylaxis with norfloxacin was more frequent in group II (15/67, 22.4% vs. 32/39, 82%, P <.0001), as a result of a higher number of patients submitted to continuous long-term prophylaxis in this group, whereas previous short-term prophylaxis was similar in both groups. Infections were more frequently nosocomial-acquired in group II than in group I (17/67, 25.3% vs. 20/39, 51.2%, P =.01). The type of infections was similar in both groups: urinary tract infections 38 in group I and 24 in group II, spontaneous bacterial peritonitis 8 and 2, spontaneous bacteremia 4 and 4, and bacterascites 1 and 0, respectively (pNS). Mortality during hospitalization was similar in the two groups (4/67, 5.9% vs. 5/39, 12.8%, pNS). None of the E. coli resistant to norfloxacin were also resistant to cefotaxime and only one of them was resistant to amoxicillin-clavulanic acid. Prophylaxis with norfloxacin, usually continuous long-term prophylaxis, favors the development of infections caused by norfloxacin-resistant E. coli. Long-term antibiotic prophylaxis should therefore be restricted to highly selected groups of cirrhotic patients at high-risk of infection. Infections caused by E. coli resistant to norfloxacin show a severity similar to those caused by sensitive E. coli. No significant associated resistance between norfloxacin and the antibiotics most frequently used in the treatment of bacterial infections in cirrhotic patients has been observed.

Aged↗
PubMed1999

Increase in quinolone resistance in a Haemophilus influenzae strain isolated from a patient with recurrent respiratory infections treated with ofloxacin.

The increase in the level of quinolone resistance of Haemophilus influenzae clinical isolates during ofloxacin therapy of a patient with recurrent respiratory infections was investigated. The first isolate (MIC of ciprofloxacin of 2 microg/ml) and the second isolate (MIC of 32 microg/ml) belonged to the same clone, as shown by pulsed-field gel electrophoresis, and the increase in the resistance level was associated with a substitution in Ser-84 to Arg in the ParC protein. These results emphasize the potential risk of development of quinolone-resistant H. influenzae during fluoroquinolone therapy in patients with recurrent respiratory infection.

Amino Acid Substitution↗
PubMed1999

[Incidence of extended spectrum beta lactamase in Escherichia coli in a university hospital from 1994-1996].

BACKGROUND: The aim of this study was to evaluate the incidence of TEM- and SHV-type extended spectrum betalactamases (ESBLs) in Escherichia coli in a 700-bed teaching hospital between 1994 and 1996. MATERIAL AND METHODS: Strains that presented reduced diameters to third-generation cephalosporins, as identified by disc diffusion techniques, were studied. The betalactamases involved were characterized by determination of the isoelectric point, hydrolysis profile, gene detection by polymerase chain reaction (PCR), and sequencing of the amplified products. RESULTS: 96 strains (1.4%) out of 7,054 strains of E. coli isolated between 1994 and 1996 showed decreased susceptibility to third-generation cephalosporins and only 4 strains (0.06%) produced ESBLs. Two strains produced SHV-2 and two produced TEM-12. CONCLUSIONS: The contribution of ESBL production to resistance to third-generation cephalosporins was low: 0.06% of all the E. coli strains isolated between 1994 and 1996.

Escherichia coli↗
PubMed1998

[Haemophilus influenzae meningitis in adults: analysis of 12 cases].

Haemophilus influenzae is an infrequent etiologic agent of bacterial meningitis in adult patients. In the last 12 years, it was the cause in 12 out of 238 cases (5.0%) of acute bacterial meningitis in adults. There were 5 men and 7 women with a mean age (SD) of 45.4 (16) years (range: 18-68 years). Seven patients (60%) had a communication between subarachnoid space and skin surface or mucosal cavities, and five (41.7%) had otitis or sinusitis. Most of the strains (9/12) were serotype b. Only one patient (8.3%) developed severe neurologic and extra-neurologic complications, and was the one who died. One of the survivors (9.1%) had partial deafness. H. influenzae is not a negligible cause of bacterial meningitis in adults. Moreover, its detection has been increasing in the last years. Patients with a cerebrospinal fluid leak, otitis or sinusitis are at high risk. The outcome is usually favorable if an early adequate therapy is given.

Adolescent↗
PubMed1998

Emergence of clinical Escherichia coli isolates with decreased susceptibility to ceftazidime and synergic effect with co-amoxiclav due to SHV-1 hyperproduction.

Between 1994 and 1996 we detected 28 out of 7054 (0.4%) clinical isolates of Escherichia coli with abnormal or reduced inhibition diameters to co-amoxiclav and ceftazidime in a disc diffusion test. The increased MIC of ceftazidime (1-32 mg/L) and the effect of synergy between this antibiotic and co-amoxiclav according to the disc diffusion test suggest the presence of an extended-spectrum beta-lactamase. However, enzymatic characterization and the nucleotide sequence confirm the hyperproduction of the SHV-1 enzyme.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1998

Increased resistance to quinolones in Campylobacter jejuni: a genetic analysis of gyrA gene mutations in quinolone-resistant clinical isolates.

Campylobacter jejuni is a frequent cause of enteritis and sometimes it requires antimicrobial therapy. We have studied the evolution of resistance to nine antibiotics from 1990 to 1994 and investigated how frequently gyrA mutations are involved in the acquisition of quinolone resistance. The percentage of chloramphenicol-, clindamycin-, tetracycline- and amoxicillin plus clavulanic acid-resistant strains has remained practically unchanged and erythromycin and gentamicin resistance has decreased, whereas the percentage of ampicillin-, nalidixic acid- or ciprofloxacin-resistant strains has almost doubled in the follow-up period, from 56 to 76% for ampicillin- and from 47.5 to 88% for quinolone-resistant strains. This study clearly shows that a mutation in Thr-86 to Ile or Lys is a frequent mechanism associated with the acquisition of a high level of resistance to quinolones in clinical isolates of C. jejuni.

Anti-Infective Agents↗
PubMed1996

[Clinical relevance of gram-negative bacteria having inducible chromosomic beta-lactamase at an intensive care unit].

BACKGROUND: The aim of the study was to determine the frequency of third-generation cephalosporins and aztreonam resistance in gram-negative bacteria with inducible chromosomal beta-lactamase (beta Lac-ind) after beta-lactam therapy in the medical-surgical intensive care unit (ICU) at a university-affiliated hospital. PATIENTS AND METHODS: We studied 34 infections in 29 patients admitted to the ICU. All were infected by strains with beta Lac-ind and all were treated with beta-lactam antibiotics. Susceptibility was determined by disc-diffusion. The beta-lactamase activity of those strains showing constitutive beta-lactamase overproduction were characterized by isoelectrofocusing. When this derepression occurred during the therapy, the strains were compared by genomic macrorestriction (PGFE). RESULTS: In 29 out of 34 infections the initial strains was susceptible. In 11 cases, the culture were not negativized in spite of their susceptible pattern. In 4 cases there was derepression during therapy. In 5 cases the initial strains were derepressed. The microorganisms isolated more frequently were Pseudomonas aeruginosa (22 cases) and Enterobacter cloacae (5 cases). The beta-lactamase activity detected correspond well with a betaLac-ind. In those cases with derepression during therapy, the initial susceptible strain and the resistant strain were identical by PGFE.

Adolescent↗