Authors:Özgür Appak, Selçuk Türkel, Nuran Esen, and Ayşe Aydan Özkütük
to antibiotics. Additionally, the definition is necessary to enable the collection of epidemiological data. In this study, the polymerase chain reaction (PCR)-restrictionenzyme analysis (PRA) method and DNA sequence analysis method were used to
Authors:Maryam Rahimpour Hesari, Ali Salehzadeh, and Reza Kazemi Darsanaki
Depending on 81 bp repeats, a strain analysis of PCR-RFLP products was performed with Hae III restrictionenzyme (Thermo Scientific, USA), where 10 μL of PCR product of coa gene was incubated with 6 U of the enzyme at 37 °C for 45 min
Authors:Zsuzsanna Varga, Boglárka Sellyei, Petra Paulus, Melitta Papp, Kálmán Molnár, and Csaba Székely
The objective of this study was to survey the incidence of Flavobacterium columnare in wild and cultured freshwater fish species in Hungary. This bacterium usually causes disease in waters of more than 25 °C temperature. However, with the introduction of intensive fish farming systems, infected fish exposed to stress develop disease signs also at lower temperatures; in addition, the temperature of natural waters rises to the critical level due to global warming. Twenty-five isolates from wild and cultured freshwater fishes were identified as F. columnare by specific PCR, although both the fragment lengths and the results of PCRRFLP genotyping with BsuRI (HaeIII) and RsaI restriction enzymes raised doubts regarding this species classification. Sequencing of the 16S ribosomal RNA gene revealed that 23 isolates belonged to the species F. johnsoniae and two represented Chryseobacterium spp. The isolates were found to have high-level multidrug resistance: all were resistant to ampicillin and polymyxin B, the 23 F. johnsoniae strains to cotrimoxazole, 88% of them to gentamicin, and 72% to chloramphenicol. The majority of the 25 isolates were sensitive to erythromycin (88%), furazolidone (76%), and florfenicol (68%).
Authors:Norma L. Calderón, Felipa Galindo-Mu?iz, Mireya Ortiz, B. Lomniczi, T. Fehervari, and L. H. Paasch
A Newcastle disease virus (NDV) isolated in Mexico and called Chimalhuacan strain was characterised by gene F restriction enzyme analysis and found to be a genotype II velogenic virus. Haematological evaluations and histological studies of bone marrow were conducted on chickens experimentally infected with the Chimalhuacan virus and on control chickens. Within 72 hours post infection (hpi), a 50% decrease in thrombocyte and monocyte counts and a complete cellular depletion in bone marrow islands were evident in the infected group. These findings suggest that the Chimalhuacan strain of NDV causes an early and severe damage of the haematopoietic cells including thrombocyte precursors, which might explain the marked thrombocytopenia detected in early stages of this disease.
Authors:Judit Pászti, Józsefné Király, and Miklós Füzi
Eighty isolates of Listeria monocytogenes cultured from human infections in Hungary between 2004 and 2012 were serotyped by the PCR technique of Doumith et al.  and characterised by pulsed-field gel electrophoresis (PFGE). Most of the isolates belonged to two serogroups: 53 isolates (66.3%) to serovar group 4b,4d,4e and 21 isolates (25.8%) to serogroup 1/2a,3a. Although many pulsotypes were identified a particular pulsotype proved highly excelling comprising of 31 isolates after digestion by both ApaI and AscI restriction enzymes. All strains from this pulsotype belonged to serovar group 4b,4d,4e. Interestingly 24% of isolates from invasive samples (cerebrospinal fluid, blood) belonged to two distinct pulsotypes in the less common serovar group 1/2a,3a. Several small clusters of cases caused by isolates with identical pulsotypes were identified.
Authors:Judit Bíró, Noémi Erdei, Ibolya Székely, and L. Stipkovits
Increasing use of Mycoplasma gallisepticum (MG) live vaccines has led to a need for the differentiation of MG strains. The MG strains MK-7, MS-16, S6, FS-9 and R strains and the MG live vaccine strain F were compared by random amplification of polymorphic DNA (RAPD) in this study. Using RAPD, different patterns were found among the MG strains. In addition to this, we examined the differentiating potential of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) primers targeted at the crmA, crmB, crmC, gapA, mgc2 and pvpA genes encoding cytadherence-related surface proteins. These proteins may take part in the pathogenesis of MG-induced disease. Differentiation of strain F is based on the identification of restriction enzyme sites in the PCR amplicons. Using HphI enzyme, crmC PCR amplicons produced different RFLP patterns. Digestion of amplicons of gapA-specific PCR with MboI enzyme also produced distinct patterns. Differences were observed among strains R and F by digestion of mgc2 PCR amplicons with HaeIII and VspI enzymes and digestion of pvpA PCR amplicons with AccI, PvuII and ScrFI endonucleases. This method can be used for the rapid differentiation of vaccine strain from wild strains. Differentiation of MG strains is a great advantage for diagnosticians or practitioners and it is useful for epidemiological studies.
Authors:Hedda Milch, Judit Pászti, I. Gadó, Katalin Glatz, and Melinda Jakab
An account is given using typing methods and detection of virulence genes of different serotypes of Escherichia coli isolated in Hungary. By hybridization using SLT-I and SLT-II probes and PCR method using stx1-2, eae and ehx primers we could differentiate O157 strains of different serotypes into eight (stx, eae, ehxA positive; stx, eae positive; stx, ehxA positive; stx positive; eae, ehxA positive; eae positive; ehxA positive; stx, eae, ehxA negative) types. The discriminatory power of phage typing proves to be much higher than that of the plasmid profile. RAPD typing with different primers could confirm or exclude the subtypes identity of the isolated E. coli O157 serotypes. Escherichia coli O157:HNM isolates could be sorted in six different phage types and six different RAPD types with ERIC-1, in five RAPD types with ERIC-2 and in seven types with M13 primers. Escherichia coli O157:H7 showed six different phage types and three RAPD types with ERIC-1 and ERIC-2 and five types with M13 primers. According to our results the standard PFGE protocol  gives the opportunity to differentiate epidemiologically independent but evolutionary related or unrelated isolates, but the practical value of PFGE method for epidemiological purposes must be confirmed by other or more restriction enzymes or using an other protocol. Summarizing our results we suggest the use of phage and RAPD typing and in doubtful cases the PFGE method.