We sought to determine whether the same Burkholderia cepacia complex strain has persisted as the dominant clonal lineage among patients in a large cystic fibrosis (CF) treatment center during the past 2 decades.
The inter-city spread of B cepacia through transfer of a colonized patient and the impact of infection control measures in containing inter-patient transmission were investigated. We analyzed all available B cepacia complex isolates recovered from 1981 to 1987 and from 1996 to 2000 at one large CF treatment center (Center A) and from 1997 to 2000 at another center (Center B). Incidence of B cepacia complex infection and infection control measures in both centers were assessed.
Seventeen (81%) of 21 Center A patients from whom B cepacia complex bacteria were recovered between 1981 and 1987 and 40 (97%) of 41 patients culture-positive between 1996 and 2000 were infected with the same genomovar III strain. Transfer of a colonized patient from Center A to Center B was associated with an increase in B cepacia complex infection in Center B, all of which was with the Center A dominant strain. This strain, designated PHDC, lacks both B cepacia epidemic strain and cblA markers.
B cepacia complex strains may remain endemic in CF treatment centers for many years. Responsible bacterial and host factors and optimal infection control measures to prevent inter-patient spread remain to be identified.
"Bcc is a complex taxonomic group and comprises seventeen closely related species, although Burkholderia cenocepacia and Burkholderia multivorans are the most common species recovered from CF patients (Coenye et al., 2001; Tablan et al., 1985). Some strains of the Bcc are resistant to several known antibiotics, including the front line drugs, trimethoprim/sulfamethoxazole, piperacillin, ceftazidime, ciprofloxacin, and pipericillin–tazobactam (Chen et al., 2001; Golini et al., 2006). Combination therapy with two or three agents is typically administered, but an optimal therapy has not been elucidated to date. "
[Show abstract][Hide abstract] ABSTRACT: The aerobic heterotrophic bacterial communities isolated from three different Antarctic sponge species were analyzed for their ability to produce antimicrobial compounds active toward Cystic Fibrosis opportunistic pathogens belonging to the Burkholderia cepacia complex (Bcc). The phylogenetic analysis performed on the 16S rRNA genes affiliated the 140 bacterial strains analyzed to 15 genera. Just three of them (Psychrobacter, Pseudoalteromonas and Arthrobacter) were shared by the three sponges. The further Random Amplified Polymorphic DNA analysis allowed to demonstrate that microbial communities are highly sponge-specific and a very low degree of genus/species/strain sharing was detected. Data obtained revealed that most of these sponge-associated Antarctic bacteria and belonging to different genera were able to completely inhibit the growth of bacteria belonging to the Bcc. On the other hand, the same Antarctic strains did not have any effect on the growth of other pathogenic bacteria, strongly suggesting that the inhibition is specific for Bcc bacteria. Moreover, the antimicrobial compounds synthesized by the most active Antarctic bacteria are very likely Volatile Organic Compounds (VOCs), a finding that was confirmed by the SPME-GC-MS technique, which revealed the production of a large set of VOCs by a representative set of Antarctic bacteria. The synthesis of these VOCs appeared to be related neither to the presence of pks genes nor the presence of plasmid molecules. The whole body of data obtained in this work indicates that sponge-associated bacteria represent an untapped source for the identification of new antimicrobial compounds and are paving the way for the discovery of new drugs that can be efficiently and successfully used for the treatment of CF infections.
"By using genetic analysis based on recA gene sequencing, B. cenocepacia was further divided into four phylogenetic lineages IIIA to IIID, but most of the CF isolates belong to IIIA and IIIB (Mahenthiralingam et al., 2000; Vandamme et al., 2003). In the United States, PHDC and Midwest clones are dominant epidemic lineages and belong to B. cenocepacia IIIB (Chen et al., 2001; Coenye and Lipuma, 2003). Strains from the PHDC lineage are also found in Europe (Coenye et al., 2004). "
[Show abstract][Hide abstract] ABSTRACT: Burkholderia cenocepacia is an opportunistic respiratory pathogen of individuals with cystic fibrosis (CF). Some strains of B. cenocepacia are highly transmissible and resistant to almost all antibiotics. Approximately one-third of B. cenocepacia infected CF patients go on to develop fatal "cepacia syndrome." During the last two decades, substantial progress has been made with regards to evasion of host innate defense mechanisms by B. cenocepacia. Almost all strains of B. cenocepacia have the capacity to survive and replicate intracellularly in both airway epithelial cells and macrophages, which are primary sentinels of the lung and play a pivotal role in clearance of infecting bacteria. Those strains of B. cenocepacia, which express both cable pili and the associated 22 kDa adhesin are also capable of transmigrating across airway epithelium and persist in mouse models of infection. In this review, we will discuss how this type of interaction between B. cenocepacia and host may lead to persistence of bacteria as well as lung inflammation in CF patients.
Frontiers in Cellular and Infection Microbiology 01/2011; 1:25. DOI:10.3389/fcimb.2011.00025 · 3.72 Impact Factor
"Several strains of the species B. multivorans, B. cenocepacia, B. cepacia, and B. dolosa have been shown to be highly transmissible among CF patients through social contact [25, 26]. In particular, highly epidemic lineages of the B. cenocepacia species have been described, including the Electrophoretic Type 12 (ET12), the Philadelphia-District of Columbia (PHDC), and the MidWest epidemic lineages [27, 28]. These epidemic strains can have an international impact, as is the case of the highly transmissible ET12 lineage. "
[Show abstract][Hide abstract] ABSTRACT: The Burkholderia cepacia complex (Bcc) comprises at least 17 closely-related species of the β-proteobacteria subdivision, widely distributed in natural and man-made inhabitats. Bcc bacteria are endowed with an extraordinary metabolic diversity and emerged in the 1980s as life-threatening and difficult-to-treat pathogens among patients suffering from cystic fibrosis. More recently, these bacteria became recognized as a threat to hospitalized patients suffering from other diseases, in particular oncological patients. In the present paper, we review these and other traits of Bcc bacteria, as well as some of the strategies used to identify and validate the virulence factors and determinants used by these bacteria. The identification and characterization of these virulence factors is expected to lead to the design of novel therapeutic strategies to fight the infections caused by these emergent multidrug resistant human pathogens.
International Journal of Microbiology 01/2011; 2011. DOI:10.1155/2011/607575
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