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89 Molecular characterization of strains of methicillin-resistant Staphylococcus aureus (MRSA) in patients with cystic fibrosis (CF)
S80
4. Microbiology
Posters
89 Molecular characterization of strains of methicillin-resistant Staphylococcus aureus (MRSA) in patients with cystic fibrosis (CF)
91 Retrospective chart review of cases of cepacia syndrome (CS) in adults with cystic fibrosis (CF)
L. Cariani1 , A. Teri1 , A. Biffi1 , D. Girelli1 , D. Guarneri1 , M. D’Accico1 , B. Beltrami1 , G. Defilippi1 , C. Colombo1 , M. Arghittu1 , E. Torresani1 . 1 CF Center and Central Lab CF Microbiology, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
M. Usacheva1 , S. Krasovskiy1 , E. Amelina1 . 1 Cystic Fibrosis, Research Institute of Pulmonology, Moscow, Russian Federation
Objectives: To evaluate the molecular profile of MRSA strains isolated from the low respiratory tract of CF patients chronically colonized, in order to investigate its origin (HA-MRSA or CA-MRSA) and to examine, in a subgroup of patients, the acquisition of strains with a different molecular profile in the course of time. Methods: Forty-four patients (9%) out of the 793 followed at the CF Centre of Milan suffer from MRSA chronic infection. Seventy-eight MRSA strains isolated from these patients have been characterized by: Multiplex PCR (mecA gene and the SCCmec-type), spa-typing and a specific PCR for Panton Valentine (PVL) gene. Thirty-four out of 44 patients have been monitored over time (T1 = 2012; T2 = 2014) in order to investigate the molecular profile of MRSA strains isolated after the first infection. Results: All 78 MRSA strains have the mecA gene; 76% present SCCmec type IV (CA-MRSA), 21% belong to spa-type t032 (UK-EMRSA-15) and 20% to spa-type t008. Among 4 strains with spa-type t008 and SCCmec type IVa (USA-300), only two show the PVL gene. The remaining 24% present SCCmec type I (HA-MRSA). The molecolar profile of the strains isolated in T2 was the same of the one isolated at T1 in 29/34 patient while 5/34 had different profile. Conclusion: The molecular characterization of MRSA strains isolated at Milan CF Centre has shown a high prevalence of CA-MRSA (SCCmec type IV). The distribution of spa-type shows to be similar to that described in other European countries. The different MRSA molecular profiles suggest to carry out genotyping analyses as well, in order to highlight the presence of clones in our CF population.
Objective: To evaluate factors influencing the efficacy of provide treatment. Methods: Retrospective chart review adult CF patients from July 2006 to December 2013. The patients were divided into two groups: response or non-response to treatment. BMI, severity of genotype, spirometry parameters, performed therapy, white blood cell count at admission and over time were estimated. Results are described as mean±SD or median (IQR). Results: 12 patients had 14 episodes of CS, 11 of which were fatal. Average age: 21.5 (6.8) years. It took 51±1.7 years from the onset of B. cepacia till the development of CS. The average white blood cell count at admission was 17.7±6.6 thousand, on the 10th–20th day among those who died − 27.3±3.4 thousand, while among the three recovery cases the decrease of leucocytes was approximately 10 thousand. Hospitalization period was 19.8±17 days. Maximum amount of simultaneously taken antibiotics: 5 in one case, 4 in five cases, 3 in five cases, 2 in two cases. On the average 4±6 changes of antibacterial therapy were required. The spirometry parameters, BMI, the amount of antibiotics, severity of genotype had no difference between the groups. Conclusion: The analysis, based on a small number of cases, did not identify the factors influencing the response rate of treatment. However, it may be assumed that sufficient decrease of white blood cell count (approximately by 10 thousand) on the 10th−20th day of therapy is a sign of relatively favorable prognosis, and deficiency of decrease is unfavorable.
90 Phenotypic and genotypic characteristics of the epidemic clones of Burkholderia cenocepacia strains in patients with cystic fibrosis (CF) in Russian Federation
92 Increasing virulence, acute phenotypic adaptations and evolving host–pathogen interactions during chronic Burkholderia cepacia complex infection of the cystic fibrosis lung
I.A. Shaginyan1 , M. Chernukha1 , L. Avetisyan1 , G. Alekseeva1 , L. Avakian2 , N. Kashirskaya2 , N. Kapranov2 . 1 N.F. Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russian Federation; 2 Research Center for Medical Genetics, Moscow, Russian Federation
N.J. Senior1 , S. Gore2 , S.C. Johnson1 , G. Vaitkute1 , K.A. Moore1 , K.H. Paszkiewicz1 , A. Kadioglu2 , A.R. Brown1 . 1 University of Exeter, Biosciences, Exeter, United Kingdom; 2 University of Liverpool, Institute of Infection & Global Health, Liverpool, United Kingdom
Background: Lung infections caused by Burkholderia cepacia complex (Bcc) are the main reasons of the development of “cepacia syndrome” that is characterized by a necrotizing pneumonia. Aim: To study phenotypic and genotypic characteristics of epidemic clones Bcc from CF patients in Russia. Methods: 129 Bcc strains were studied by diagnostic algorithm included phenotypic and molecular techniques. Results: The Russian Bcc strains belonged to B. cenocepacia − 166 strains, B. multivorans − 2, B. contaminans − 2, B. vietnamensis − 1. The strains of B. cenocepacia belonged to ST 709, 208, 241, 710, 708, 714, 727, 728. Dominant ST 709 was identified in 67.6% of patients, ST 208 in 12.4%. The contamination by strains ST 709 and ST 208 is supposed to occur during hospitalizations in Moscow and Samara. The strains ST 709 and ST 208 had lipase and proteolytical activity. 100% of strains were resistant to amikacin, gentamycin, tobramicin and imipenem, 14% to meropenem, 17.9% to ceftazidime. All Bcc strains were multiresistant. 83% of the strains had the ability to grow as a biofilm. PCR-based molecular analysis revealed the presence of BCESM marker in all strains. Microbiological monitoring revealed that the strains isolated at the beginning were identical to the strains isolated after 5 years. The change of the Bcc strains during the chronic infection or their elimination was not observed. Conclusion: The predominant epidemical clones were Moscow ST 709 and Samara ST 208. They are multiresistant, have ability to persist in CF patient lungs and cause cross-infections. For improvement in the quality of life and long time survival of CF patients the monitoring of Bcc infection is absolutely necessary.
Objectives: We aimed to define the phenotypic and genotypic adaptations that occur in the Burkholderia cepacia complex (BCC) during chronic infection of the cystic fibrosis (CF) lung. Methods: We studied a total of 57 BCC isolates from 15 CF patients (2−6 isolates per patient), spanning infection periods ranging from 3 to 14 years. We assessed virulence using the Galleria mellonella model, and phenotypically characterized all isolates to determine how individual traits evolve during infection. Genome sequencing of selected early and late isolates provided insight into the genetic basis of the adaptations, whilst selected isolates were also studied in a murine infection model and in vitro macrophage model. Results: Strikingly, during infection of 4 BCC-infected patients, the virulence of longitudinal isolates increased. Those patients were infected with either the B. cenocepacia ET-12 lineage (n = 3) or a B. multivorans outbreak strain (n = 1), both of which are linked with poor clinical outcome. Increasing virulence was uniformly correlated with increased haemolytic activity and decreased biofilm formation, consistent with the emergence of an ‘acute phenotype’. Late isolates displaying heightened virulence also exhibited altered host–pathogen interactions, with delayed clearance from Galleria and/or murine infection models, and reduced uptake by macrophages in vitro. Genome sequencing of isolates revealed evidence of convergent evolution, with comparable phenotypic adaptations arising through distinct genetic mutations. Conclusion: BCC adaptation strategies within the CF lung differ from those observed in Pseudomonas aeruginosa, and may contribute to poor clinical outcome.
4. Microbiology
Posters
89 Molecular characterization of strains of methicillin-resistant Staphylococcus aureus (MRSA) in patients with cystic fibrosis (CF)
91 Retrospective chart review of cases of cepacia syndrome (CS) in adults with cystic fibrosis (CF)
L. Cariani1 , A. Teri1 , A. Biffi1 , D. Girelli1 , D. Guarneri1 , M. D’Accico1 , B. Beltrami1 , G. Defilippi1 , C. Colombo1 , M. Arghittu1 , E. Torresani1 . 1 CF Center and Central Lab CF Microbiology, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, Italy
M. Usacheva1 , S. Krasovskiy1 , E. Amelina1 . 1 Cystic Fibrosis, Research Institute of Pulmonology, Moscow, Russian Federation
Objectives: To evaluate the molecular profile of MRSA strains isolated from the low respiratory tract of CF patients chronically colonized, in order to investigate its origin (HA-MRSA or CA-MRSA) and to examine, in a subgroup of patients, the acquisition of strains with a different molecular profile in the course of time. Methods: Forty-four patients (9%) out of the 793 followed at the CF Centre of Milan suffer from MRSA chronic infection. Seventy-eight MRSA strains isolated from these patients have been characterized by: Multiplex PCR (mecA gene and the SCCmec-type), spa-typing and a specific PCR for Panton Valentine (PVL) gene. Thirty-four out of 44 patients have been monitored over time (T1 = 2012; T2 = 2014) in order to investigate the molecular profile of MRSA strains isolated after the first infection. Results: All 78 MRSA strains have the mecA gene; 76% present SCCmec type IV (CA-MRSA), 21% belong to spa-type t032 (UK-EMRSA-15) and 20% to spa-type t008. Among 4 strains with spa-type t008 and SCCmec type IVa (USA-300), only two show the PVL gene. The remaining 24% present SCCmec type I (HA-MRSA). The molecolar profile of the strains isolated in T2 was the same of the one isolated at T1 in 29/34 patient while 5/34 had different profile. Conclusion: The molecular characterization of MRSA strains isolated at Milan CF Centre has shown a high prevalence of CA-MRSA (SCCmec type IV). The distribution of spa-type shows to be similar to that described in other European countries. The different MRSA molecular profiles suggest to carry out genotyping analyses as well, in order to highlight the presence of clones in our CF population.
Objective: To evaluate factors influencing the efficacy of provide treatment. Methods: Retrospective chart review adult CF patients from July 2006 to December 2013. The patients were divided into two groups: response or non-response to treatment. BMI, severity of genotype, spirometry parameters, performed therapy, white blood cell count at admission and over time were estimated. Results are described as mean±SD or median (IQR). Results: 12 patients had 14 episodes of CS, 11 of which were fatal. Average age: 21.5 (6.8) years. It took 51±1.7 years from the onset of B. cepacia till the development of CS. The average white blood cell count at admission was 17.7±6.6 thousand, on the 10th–20th day among those who died − 27.3±3.4 thousand, while among the three recovery cases the decrease of leucocytes was approximately 10 thousand. Hospitalization period was 19.8±17 days. Maximum amount of simultaneously taken antibiotics: 5 in one case, 4 in five cases, 3 in five cases, 2 in two cases. On the average 4±6 changes of antibacterial therapy were required. The spirometry parameters, BMI, the amount of antibiotics, severity of genotype had no difference between the groups. Conclusion: The analysis, based on a small number of cases, did not identify the factors influencing the response rate of treatment. However, it may be assumed that sufficient decrease of white blood cell count (approximately by 10 thousand) on the 10th−20th day of therapy is a sign of relatively favorable prognosis, and deficiency of decrease is unfavorable.
90 Phenotypic and genotypic characteristics of the epidemic clones of Burkholderia cenocepacia strains in patients with cystic fibrosis (CF) in Russian Federation
92 Increasing virulence, acute phenotypic adaptations and evolving host–pathogen interactions during chronic Burkholderia cepacia complex infection of the cystic fibrosis lung
I.A. Shaginyan1 , M. Chernukha1 , L. Avetisyan1 , G. Alekseeva1 , L. Avakian2 , N. Kashirskaya2 , N. Kapranov2 . 1 N.F. Gamaleya Research Centre of Epidemiology and Microbiology, Moscow, Russian Federation; 2 Research Center for Medical Genetics, Moscow, Russian Federation
N.J. Senior1 , S. Gore2 , S.C. Johnson1 , G. Vaitkute1 , K.A. Moore1 , K.H. Paszkiewicz1 , A. Kadioglu2 , A.R. Brown1 . 1 University of Exeter, Biosciences, Exeter, United Kingdom; 2 University of Liverpool, Institute of Infection & Global Health, Liverpool, United Kingdom
Background: Lung infections caused by Burkholderia cepacia complex (Bcc) are the main reasons of the development of “cepacia syndrome” that is characterized by a necrotizing pneumonia. Aim: To study phenotypic and genotypic characteristics of epidemic clones Bcc from CF patients in Russia. Methods: 129 Bcc strains were studied by diagnostic algorithm included phenotypic and molecular techniques. Results: The Russian Bcc strains belonged to B. cenocepacia − 166 strains, B. multivorans − 2, B. contaminans − 2, B. vietnamensis − 1. The strains of B. cenocepacia belonged to ST 709, 208, 241, 710, 708, 714, 727, 728. Dominant ST 709 was identified in 67.6% of patients, ST 208 in 12.4%. The contamination by strains ST 709 and ST 208 is supposed to occur during hospitalizations in Moscow and Samara. The strains ST 709 and ST 208 had lipase and proteolytical activity. 100% of strains were resistant to amikacin, gentamycin, tobramicin and imipenem, 14% to meropenem, 17.9% to ceftazidime. All Bcc strains were multiresistant. 83% of the strains had the ability to grow as a biofilm. PCR-based molecular analysis revealed the presence of BCESM marker in all strains. Microbiological monitoring revealed that the strains isolated at the beginning were identical to the strains isolated after 5 years. The change of the Bcc strains during the chronic infection or their elimination was not observed. Conclusion: The predominant epidemical clones were Moscow ST 709 and Samara ST 208. They are multiresistant, have ability to persist in CF patient lungs and cause cross-infections. For improvement in the quality of life and long time survival of CF patients the monitoring of Bcc infection is absolutely necessary.
Objectives: We aimed to define the phenotypic and genotypic adaptations that occur in the Burkholderia cepacia complex (BCC) during chronic infection of the cystic fibrosis (CF) lung. Methods: We studied a total of 57 BCC isolates from 15 CF patients (2−6 isolates per patient), spanning infection periods ranging from 3 to 14 years. We assessed virulence using the Galleria mellonella model, and phenotypically characterized all isolates to determine how individual traits evolve during infection. Genome sequencing of selected early and late isolates provided insight into the genetic basis of the adaptations, whilst selected isolates were also studied in a murine infection model and in vitro macrophage model. Results: Strikingly, during infection of 4 BCC-infected patients, the virulence of longitudinal isolates increased. Those patients were infected with either the B. cenocepacia ET-12 lineage (n = 3) or a B. multivorans outbreak strain (n = 1), both of which are linked with poor clinical outcome. Increasing virulence was uniformly correlated with increased haemolytic activity and decreased biofilm formation, consistent with the emergence of an ‘acute phenotype’. Late isolates displaying heightened virulence also exhibited altered host–pathogen interactions, with delayed clearance from Galleria and/or murine infection models, and reduced uptake by macrophages in vitro. Genome sequencing of isolates revealed evidence of convergent evolution, with comparable phenotypic adaptations arising through distinct genetic mutations. Conclusion: BCC adaptation strategies within the CF lung differ from those observed in Pseudomonas aeruginosa, and may contribute to poor clinical outcome.