No abstract

The gene encoding major adhesin protein P1 of Mycoplasma pneumoniae, MPN141, contains two DNA sequence stretches, designated RepMP2/3 and RepMP4, which display variation among strains. This variation allows strains to be differentiated into two major P1 genotypes (1 and 2) and several variants. Interestingly, multiple versions of the RepMP2/3 and RepMP4 elements exist at other sites within the bacterial genome. Because these versions are closely related in sequence, but not identical, it has been hypothesized that they have the capacity to recombine with their counterparts within MPN141, and thereby serve as a source of sequence variation of the P1 protein. In order to determine the variation within the RepMP2/3 and RepMP4 elements, both within the bacterial genome and among strains, we analysed the DNA sequences of all RepMP2/3 and RepMP4 elements within the genomes of 23 M. pneumoniae strains. Our data demonstrate that: (i) recombination is likely to have occurred between two RepMP2/3 elements in four of the strains, and (ii) all previously described P1 genotypes can be explained by inter-RepMP recombination events. Moreover, the difference between the two major P1 genotypes was reflected in all RepMP elements, such that subtype 1 and 2 strains can be differentiated on the basis of sequence variation in each RepMP element. This implies that subtype 1 and subtype 2 strains represent evolutionarily diverged strain lineages. Finally, a classification scheme is proposed in which the P1 genotype of M. pneumoniae isolates can be described in a sequence-based, universal fashion.

An international multicenter study was undertaken to investigate the epidemiological dynamics of penicillin-resistant pneumococci. We compared the molecular epidemiological characteristics of 205 penicillin-resistant isolates originating from The Netherlands, Thailand, United States, Spain, Greece, Poland, Cuba, Germany, Finland, United Kingdom, South Africa, Hungary, Portugal, Croatia, and the Czech Republic. Eighty-four distinct restriction fragment end labeling (RFEL) types were observed. Twenty-eight genetic types were shared by two or more strains. Five genetic clusters consisted of strains originating from different countries, illustrating dissemination of penicillin-resistant pneumococci among countries. The strains displaying the two predominant RFEL types corresponding with the pandemic clones 23F and 9V were found in 10 and 6 different countries, respectively. This clearly demonstrates the pandemic behavior of these two clones. Twelve out of the 28 genetic clusters contained two or more serotypes. This finding indicates frequent horizontal transfer of capsular genes. Within distinct RFEL types, identical penicillin binding protein (PBP) genotypes were often observed, suggesting a high frequency of horizontal transfer of penicillin resistance genes. The most predominant PBP type was found in 15 distinct RFEL types, comprised 44% of the entire collection, and was observed in 11 countries. The vast majority of the strains belonging to the pandemic clones 23F and 9V shared this predominant PBP type. We hypothesize that the clones 23F and 9V are responsible for the worldwide increase of penicillin-resistance, because they serve as a genetic reservoir for susceptible pneumococci to acquire penicillin resistance.

Small for gestational age and prolonged hospitalization were associated with CoNS sepsis. The icaA gene is a predictor for biofilm formation in S. epidermidis, but not in other species. Multiresistance is not associated with clonality.

No abstract