ABSTRACT
Listeria monocytogenes infection affects people throughout the all world, most often causing gastrointestinal disturbances, less inflammation of the central nervous system (meningitis, meningoencephalitis, absceses), sepsis, endocarditis and dispersed focal inflammation. Listeria monocytogenes infection in pregnant woman can lead also to premature birth or abortion. Listeriosis is a serious problem because of the high mortality in case of generalized infection, which can reach up to 20%. Listeria strains could be identified by determination of biochemical features--characteristic for each Listeria species. Biochemically identified strains could be serotyped using Seeliger method. Many authors developed a molecular biology-based methods of Listeria serotype determination The Doumith's method divide all Listeria monocytogenes serotypes for five genoserogroups. The purpose of this study was to determine the genoserogroups of Listeria monocytogenes strains and compare those results with results obtained by classical serotyping by Seeliger method. To this work 90 Listeria strains were used: 75 Listeria monocytogenes strains from clinical, food and environmental samples and 15 reference strains from Pasteur Institute collection and National Institute of Public Health--National Institute of Hygiene collection. All strains were serotyped using liquid stable antisera for determination of O and H Listeria monocytogenes antigens (Mast Diagnostic, UK). Multiplex PCR for Listeria monocytogenes serovars differentiation were performed according to Doumith et al procedure. The genoserogroup obtained from multiplex PCR of 10 Listeria monocytogenes reference strains were compatible with real serotype. In case of non-Listeria monocytogenes reference strains in multiplex-PCR, they were identified as non-monocytogenes. In group of 75 non-reference strains isolated from human, food and environmental sources, 34 belonged to genoserogroup I.1, two strains to genoserogroup I.2, 11 strains to genoserogroup II.1, 21 strains belonged to genoserogroup II.2 and 9 strains to genoserogroup III.
Subject(s)
Listeria monocytogenes/classification , Listeria monocytogenes/genetics , Polymerase Chain Reaction/methods , Serotyping/methods , Environmental Microbiology , Food Microbiology , Humans , Listeria monocytogenes/isolation & purification , Species SpecificityABSTRACT
The frequency of occurrance of Listeria strains in different food products was determined. Biochemical characteristic of the isolated strains was achieved in accordance with procedure included in PNEN ISO 11290 standard, genus was determined byApiListeria (bioMéieux) test. Sensitivity to selected antibacterial medicines was investigated using disck method and Mueller-Hinton 2 Agar medium. From the 577 examinated food samples 126 strains of Listeria were isolated and among them: 34.1% L. monocytogenes, 36,5% L. welshimeri, 19.0% L. innocua, 3.17% L. grayi, 0.79% L. seeligeri, 0.79% L. seeligeri/welshinmeri and 5.56% L. ivelshimeri/innocua. L. monocytogenes strains most often were found in minced pork, culinary products and in frozen vegetables. On the base of ApiListeria (bioMéieux) test the isolated L. monocytogenes strains were qualified into 2 biochemical types. It was found that all L. monocytogenes were sensitive to sulphametaksazol/trimetoprim and ampicyllin, 25% of strains were moderatety sensitive to penicillin and only 2 L. monocytogenes strains were resistant to gentamicin. Presence of Listeria spp. microorganisms in food products may be an production hygiene indicator for critical control point and show the possibility of contamination with L. monocytogenes strains.
Subject(s)
Food Microbiology , Listeria/classification , Listeria/isolation & purification , Animals , Anti-Bacterial Agents/pharmacology , Drug Resistance, Microbial , Food Contamination , Humans , Incidence , Listeria/drug effects , Microbial Sensitivity Tests , PolandABSTRACT
From the 1572 food samples, examined in Microbiology Department of Frozen Food Industry Research Laboratory in Lódz, 79 (5.0%) coagulase-positive staphylococci strains were isolated. All the strains were sensitive to vancomycin, gentamycin and chloramphenicol. Only individual staphylococci strains were resistant to erythromycin (1.3%), lincomycin (2.5%) and ciprofloxacin (2.5%). 20.3% strains, isolated mainly from raw meat, were resistant to doxycycline and 6.3% to oxacillin. 38.0% of coagulase-positive staphylococci strains had positive results of cefinase test. One strain isolated from minced meat was resistant to methicillin and at the same time it was producing beta-lactamases.
Subject(s)
Coagulase/metabolism , Drug Resistance, Bacterial , Food Microbiology , Staphylococcus/drug effects , Humans , Meat/microbiology , Microbial Sensitivity Tests , Staphylococcus/enzymology , Staphylococcus/isolation & purificationABSTRACT
The aim of the study was to isolate extended spectrum beta-laktamases (ESBL) and chromosomal beta-laktamases AmpC producing strains from food products. A total of 739 Gram-negative bacteria were tested with double disc diffusion method using cefotaxim, ceftasidim and amoxycillin with clavulanic acid. One strain producing ESBL and belonging to Stenotrophomonas maltophilia was detected from the ice cream (0.14% of all strains). From different food products a total of 14 microorganisms (1.9%) having AmpC enzymes have been isolated. They belonged to Enterobacter spp, Hafnia spp, Morganella spp, Citrobacter, Acinetobacter, and Cedecea. Appearance of strains producing beta-laktamases ESBL and AmpC among microorganism isolated from food make it necessary to monitor enzymes activity during routine microbiological control of foods.
Subject(s)
Bacterial Proteins , Food Microbiology , Gram-Negative Aerobic Rods and Cocci/enzymology , Gram-Negative Aerobic Rods and Cocci/isolation & purification , beta-Lactamases/metabolism , Gram-Negative Aerobic Rods and Cocci/classification , Ice Cream/microbiology , Species Specificity , beta-Lactamases/classificationABSTRACT
In the years 2000-2001 eighty nine portions (445 samples) of minced meat (beef and pork, beef, pork, veal, turkey) produced by supermarkets and other meat producers from Lódz and around Lódz were examined to check if they meet the standard requirements of PN-97/A-82009 and PN-97/A-82009/A1. The following parameters were determined according to PN-94/A-82055: the total number of microorganisms, most probable number of Escherichia coli, enumeration of Staphylococcus aureus and detection of Salmonella. In addition the presence of Listeria was determined in 25 g of examined meat. The examination showed that 36 (40.4%) portions of minced meat did not meet the requirements of standards mainly because the number of most probable number of E. coli exceeded the norm values.
