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S Berrón

Publications and source records attributed to S Berrón.

33 records · Page 2Linked to original sources
PubMed1996

Multiply antibiotic-resistant Streptococcus pneumoniae recovered from Spanish hospitals (1988-1994): novel major clones of serotypes 14, 19F and 15F.

We analysed a collection of 95 multiply antibiotic-resistant pneumococci, recovered since 1988 from 14 Spanish hospitals, that have MICs > or = 0.25 microgram benzylpenicillin ml-1. The majority of the isolates were of serogroups 14, 23, 6, 19 and 15, which are currently the serogroups mainly associated with multiresistance in Spain. All of the serogroup 23 isolates were members of the major Spanish serotype 23F multiresistant clone. Similarly, most of the serogroup 6 isolates were members of the major multiresistant serotype 6B clone, or variants of this clone. Eighteen of the 24 isolates of serogroup 19 were members of a highly penicillin-resistant clone that appears to be a serotype 19F variant of the major Spanish serotype 23F multiresistant clone. Eighteen of the 25 isolates of serotype 14 were members of a previously uncharacterized highly penicillin-resistant clone. Thirteen of the 16 isolates of serogroup 15 were members of a single previously unreported clone of serotype 15F that had moderate levels of resistance to penicillin. Approximately 65% of the multiresistant pneumococci that are currently circulating in Spain were members of the three new clones of serotype 14, 15F and 19F that we describe here, or the previously described serotype 6B and 23F clones. The other 35% of isolates were minor variants of the major clones, unrelated minor clones, and unique isolates, many of which appeared to have arisen by horizontal gene transfer events.

Bacterial Proteins↗
PubMed1995

Interspecies recombination in nature: a meningococcus that has acquired a gonococcal PIB porin.

A vaginal isolate of Neisseria has been reported to resemble Neisseria meningitidis in biochemical characteristics but to react with serological reagents that are specific to the PI porin from Neisseria gonorrhoeae. We have confirmed that this isolate has the biochemical attributes of a meningococcus and have shown that it clusters among meningococcal isolates on a dendrogram based on isoenzyme variation within housekeeping enzymes from populations of N. meningitidis and N. gonorrhoeae. Furthermore, the sequences of the fbp and adk genes were typical of those of N. meningitidis and were distinct from those of N. gonorrhoeae. However, the porB gene was very similar to the por genes of N. gonorrhoeae isolates that express the PIB class of outer-membrane porin (differing from one gonococcal por allele at only a single nucleotide site), and was clearly distinct from the porB genes of N. meningitidis. The isolate therefore appears to be a typical meningococcus, except that its porB gene has been replaced with the por gene from a gonococcus.

Adenylate Kinase↗
PubMed1994

Increase in moderate penicillin resistance and serogroup C in meningococcal strains isolated in Spain. Is there any relationship?

Serogroup B Neisseria meningitidis is the main cause of meningococcal disease in Spain, but in recent years we have detected an increase in the prevalence of infection due to serogroup C meningococci. At the same time, the frequency of moderately penicillin-resistant (PenR) clinical isolates, which include greater numbers of serogroup C meningococci than do penicillin-susceptible (PenS) strains, has also been increasing. When we analyzed the prevalence of serogroups B and C in PenR and PenS meningococcal strains, we found a simultaneous increase in serogroup C strains and a decrease in serogroup B meningococci affecting both PenR and PenS isolates. To analyze this epidemiological change in Spain, we have applied serotyping, subtyping, and multilocus enzyme electrophoresis to serogroup C (PenR and PenS) strains. The two major serotypes were 2b and 2a in both groups (PenR and PenS), but our results suggested an association between serotype 2b and PenR strains. However, multilocus enzyme electrophoresis showed that 75% of the major serotypes belonged to the same electrophoretic type. It does not appear that a new clone distinct from those already established is contributing to the increase in serogroup C meningococci in Spain.

Bacterial Typing Techniques↗
PubMed1992

Epidemiology and molecular basis of penicillin-resistant Neisseria meningitidis in Spain: a 5-year history (1985-1989).

Penicillin-resistant (penr) clinical isolates of Neisseria meningitidis, which do not produce beta-lactamase, were first identified in Spain in 1985; the frequency of their recovery, which has been increasing in the past few years, reached 20% in 1989. Serogrouping, determination of serotypes and subtypes, and multilocus enzyme electrophoresis of the penr strains showed an extensive diversity. Resistance is due, at least in part, to a decreased affinity of penicillin-binding protein (PBP) 2 for penicillin. Similar low-affinity forms of PBP 2 are also found in penr isolates of Neisseria lactamica, Neisseria polysaccharea, and Neisseria gonorrhoeae. Genetic transformation of an N. meningitidis type strain to low-level penicillin resistance with DNA from resistant meningococci and other Neisseria species resulted in transformants that possessed low-affinity forms of PBP 2. These altered forms of PBP 2 have been shown to arise from recombinational events that replace parts of the PBP 2 gene with the corresponding regions from the PBP 2 genes of commensal Neisseria species.

Bacterial Proteins↗
PubMed1987

Analysis of penicillinase-producing Neisseria gonorrhoeae isolates in Madrid (Spain) from 1983-85.

Between April 1983 and December 1985, 576 strains of Neisseria gonorrhoeae were isolated in our laboratory from patients attending Sexually Transmitted Diseases (STD) clinics. Of these, 61 (10.6%) were penicillinase-producing. Studies on these strains by plasmid analysis, auxotyping and serogrouping showed that the predominant type strains harboured the Asian resistance plasmid, were prototrophic, and were of serogroup W II/W III. About half of the strains, both of the African and Asian type, harboured the transfer plasmid. Strains of serogroup W II/W III were less sensitive to tetracycline and cefoxitin than serogroup W I strains.

Cefoxitin↗
PubMedDate not supplied

Gonorrhea in women prostitutes: clinical data and auxotypes, serovars, plasmid contents of PPNG, and susceptibility profiles.

Eighty-nine women prostitutes who underwent clinical and microbiologic examination were found to have gonococcal infection. The median age was 22; 92.1% were from urban areas. Nearly all the women prostitutes refrained from barrier methods (92.1%) and had contact with several partners (91.0%). The most frequent clinical findings were leukorrhea (50.6%), cervicitis (20.2%), and pelvic inflammatory disease (PID) (18.0%). Eighty-one women prostitutes (93.1%) had experienced a previous STD, with Chlamydia trachomatis (34.8%), Trichomonas vaginalis (30.3%), Neisseria gonorrhoeae (29.2%), and Ureaplasma urealyticum (23.6%) as the most frequent microorganisms isolated. Microorganisms associated with N. gonorrhoeae were isolated, mainly T. vaginalis (40.4%), C. trachomatis (31.5%), and Mycoplasma hominis (21.3%). For N. gonorrhoeae, the most frequent auxotypes were prototrophic (67.4%) and Proline (Pro)-dependent (14.6%); 2.2% of the strains were non-auxotypable. Beta-lactamase production was detected in three strains (3.4%) belonging to the auxotype/serovar: Lys/IA, Prototrophic/IB, and Pro/IB. The two former produced the 3.2-MDa "African" plasmid; the latter produced two plasmids (the 4.5-MDa "Asian" and the 24.5-MDa transfer plasmid.

Adult↗