ABSTRACT
A total of 90 Pseudomonas aeruginosa strains isolated from 4 hospitals in the west-north region of Poland were studied by arbitrarily primed polymerase chain reaction (AP-PCR). AP-PCR results revealed the presence of 11 main groups of patterns (A-K) and 5 unique patterns among isolates. Generally, they were characterized by high resistance to antibiotics tested and significant differences in serogroups and types of growth on Cetrimide Agar medium. It was observed that clonally related strains were isolated from patients within the same ward, among different wards as well as in distant hospitals.
Subject(s)
Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial , Pseudomonas Infections/classification , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/genetics , DNA Fingerprinting , Genotype , Hospitals , Humans , Microbial Sensitivity Tests/statistics & numerical data , Phenotype , Poland/epidemiology , Pseudomonas Infections/drug therapy , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , SerotypingABSTRACT
Forty-seven Listeria monocytogenes strains isolated during a year in a selected Polish fish-processing plant as well as 7 L. monocytogenes strains of different origins (including a reference strain) were analyzed in our studies. Strains were isolated from raw fish fillets (flounder), frozen coated flounder fillets, coating ingredients, and the processing environment. Isolation of strains covered the period of a sanitization program introduced in the plant. L. monocytogenes was identified using conventional microbiological methods and the PCR technique. RAPD (random amplified polymorphic DNA) technique for fingerprinting was applied to analyze the intraspecies diversity. Six RAPD types (A-F) and seven unique strains were revealed as a result of fingerprinting with one persistent type isolated from July 1999 to February 2000. It was detected for the first time after one month of sanitization. Its occurrence could have been promoted by clone selection either due to ineffective disinfection or to resistance against the disinfectant. As L. monocytogenes mostly occurred on frozen products, this indicates that contamination could start during product freezing, cold storage, or handling. The results revealed that there is a crucial need for preparing sanitization schemes precisely targeted at L. monocytogenes to avoid its recurrence as persistent 'in-house' strains. The possibility of incorrect interpretations of classical microbiological test results as well as the necessity to introduce assays based on nucleic acid analysis into epidemiological investigations were emphasized.
Subject(s)
Disinfection/methods , Flounder/microbiology , Food Microbiology , Listeria monocytogenes/isolation & purification , Animals , DNA, Bacterial/analysis , Disinfectants , Food-Processing Industry/standards , Humans , Listeria monocytogenes/genetics , Listeriosis/microbiology , Listeriosis/prevention & control , Poland , Polymerase Chain Reaction , Random Amplified Polymorphic DNA TechniqueABSTRACT
Recently methods based on analysis of arbitrarily amplified target sites of microorganism genomes have been extensively applied in microbiological studies. The range of their applications is limited by problems with discrimination and reproducibility resulting from lack of standardised and reliable methods of optimisation. By orthogonal-array optimisation most advantageous and optimal parameters for highly discriminatory primers (CagA2+CMVin2) were selected and efficient AP-PCR (arbitrarily primed-polymerase chain reaction) fingerprinting conditions for Pseudomonas aeruginosa isolates were set up. Stable and multiplex amplicon profiles obtained in this study revealed high level of intraspecies DNA polymorphism among 20 analysed clinical strains of P. aeruginosa proving optimised AP-PCR fingerprinting to be useful in epidemiological typing of the species.
