[In vitro susceptibility to antibiotics and the most common Streptococcus pneumoniae serotypes: a multicenter study]

The susceptibility and serotypes of 211 strains of Streptococcus pneumoniae collected from 12 Spanish hospitals in December 2003 were studied. Susceptibility tests for eight antibiotics were carried out by E-test, and the serotype classification was carried out using pneumococcus antiserum from the Copenhagen Statens Serum Institute. Overall, the most frequent serotypes were 19 (12.2%); 6 (10.7%); 23 (10.2%); 3 (8.1%); 9 (6.6%); 14 (6.1%); and 29 (5.1%). In blood, the most frequent were 19 (16.6%) and 14 (11.9%), and 8.6% were nontypable. Under NCCLS (M7-A5) criteria, 55.6% of the strains were susceptible to penicillin (MIC < or =0.06 mg/l) and 7.9% showed high resistance (MIC > or =2 mg/l). Susceptibility to other antibiotics was 98% to moxifloxacin; 97.1% to levofloxacin; 94.6% to amoxicillin-clavulanic acid; 71.2% to cefuroxime; 84.4% to ceftriaxone; and 63.1% to clarithromycin and azithromycin. Only 13.3% of the strains showed susceptibility to the antibiotics tested. The greatest percentage of strains resistant to other antibiotics was found among the strains resistant to penicillin. Nine resistant phenotypes were detected.

[Coverage of the 23-valent pneumococcal vaccine in those older than 64 years of age in the region of Castellon and Valencia, Spain]

The different serotypes of Streptococcus pneumoniae isolated from adults aged over 64 years in the Valencia and Castellon health region of Spain from June 1999 to December 2003 were analyzed. A total of 163 strains were evaluated; 58.3% were invasive, 47.24% were from respiratory source, and 4.9% were from exudates. The greatest percentage of samples was obtained from the group of patients aged 65 to 75 years (60.7%), while the lowest percentage was obtained from the group of patients aged over 85 years (10.4%). In the latter group, 53% of the strains were invasive and 29.4% were isolated from sputum. A total of 21 serotypes were identified, with the most common (> 3%) being: serotype 3 (22.1%); serotype 19 (12.9%); serotype 6 (12.3%); serotype 9 (8.6%); serotype 14 (10.4%); serotype 23 (8%); serotype 29 (3.7%); and serotype 18 (3.1%). Serotype 3 was the most common serotype found in all samples, with the exception of exudate, while serotype 23 was not isolated in blood. In this population group, the coverage of the 23-valent vaccine was 88.4%. Serotypes not included in this vaccine but isolated from invasive samples were serotypes 16, 24, 29 and 35. No changes were observed in serotype distribution over the 4-year period of the study. However, it is necessary to continue epidemiological monitoring to determine whether serotype substitution occurs.

[Haemophilus influenzae and betalactam resistance: description of bla TEM gene deletion]

The resistance to betalactam antibiotics in a total of 177 clinical isolates of Haemophilus influenzae, mostly from respiratory tract samples and characterized by their betalactamase production, was studied using the cephalosporin chromogenic assay and by detecting bla(TEM) and bla(ROB) genes. A substantial number of clinical isolates carrying the bla(TEM) gene, which presented a mutation consisting of the absence of a fragment of 136 base pairs, located upstream from the coding region including the 35 but not the 10 region of the promoter were found. This suggests that a new bla(TEM) promoter exists in these strains. This finding was associated with increased resistance to the antibiotics cefaclor and loracarbef compared with normal isolates. It was also found that 3.9% of the isolates carried the bla(ROB-1) gene.

[Study of the betalactam resistance of Haemophilus influenzae conferred by the bla(ROB-1) gene]

Given the lack of information on the resistance to betalactams conferred by the bla(ROB-1) gene in our area, we decided to undertake a study to determine if and how often it appears in our isolates. We analyzed the presence of the gene in 177 strains of Haemophilus influenzae and compared the results with those from the biochemical tests (nitrocefin). Sixty-three strains tested positive in the nitrocefin test (35.6%). The presence of the bla(ROB-1) gene was detected in seven of the 177 strains (3.9%). All the strains expressing the gene also tested positive in the nitrocefin test. Of the 63 strains that showed biochemical resistance (positive to nitrocefin), seven were found to be caused by the presence of the bla(ROB-1) gene. An epidemiological follow-up for the presence of this gene in our area is therefore advisable.

[Listeriosis in the adult: presentation of 14 cases]

The incidence of Listeria monocytogenes (LM) infection has increased in recent years, particularly in immunocompromised patients or in those with severe underlying diseases. However, it still is an unusual pathogen. In the present study we report 14 cases of listeriosis in adults, seen from 1978 to 1988. The organism was isolated from the blood in 10 instances, from cerebrospinal fluid in 5, and from a cervical abscess in one. The ages of the patients ranged from 29 to 81 years and there was a clear male predominance. In all cases except in one there was a previous underlying disease, and four had received immunosuppressant therapy. Listeria monocytogenes was sensitive to ampicillin, erythromycin, vancomycin, gentamicin, rifampicin, ticarcillin, azlocillin, mezlocillin and tetracyclines.

The evolution of the sensitivity to fosfomycin over the past two years

The sensitivity of 1,823 bacteriological strains of differing types is shown (E. coli, Klebsiella-Enterobacter-Serratia, Proteus-Providence, Pseudomonas, Salmonella-Shigella-Citrobacter, Haemophilus, Staphylococcus and Streptococcus); all of clinical origin, isolated during March and April, 1975. The methods used were series of double dilutions in Mueller-Hinton agar and the disc-plate method (weight of 50 mug). A comparative study is made of the sensitivity between a part of the present strains (1,725) and another group of 1,664 germs, isolated and observed in January and February, 1973. Some variations are observed which, on general lines, do not seem to be significant, except for Klebsiella-Enterobacter and Serratia.

Renal insufficiency and fosfomycin

After the parenteral injection of 1 g sodium salt of fosfomycin the serum levels of the antibiotic are detected in a series of eight adult patients with different degrees of chronic renal insufficiencies four of them submitted to periodical dialysis. The results obtained reveal that the levels as well as the time of elimination of fosfomycin maintain an obvious relation to the degree of renal insufficiency in the patients.