The influence of lactic acid bacteria on the viability of the reference strain of Listeria monocytogenes 123 serotype I in plant foods

Listeria (L.) monocytogenes is the causative agent of human listeriosis, the frequent sourceof which is food of animal origin. The aim of this study was to determine the influence of lactic acid bacteria (LAB) on the viability of Listeria in carrot juice and compound feed inoculated with L. monocytogenes. The effect of homogenous cultures of Streptococcus (Str.) lactis distaticus, Str. thermophilus and Lactobacillus (Lac.) lactis subsp. Cremoris and the combination of Str. thermophilus with Lac. bulgaricus in the carrot juice and compound feed samples on viability of inoculated L. monocytogenes were examined. There were no statistically significant differences in the results between the experimental groups. Regardless of used LAB, the results showed that the mean pH values in the carrot juice samples decreased from an initial pH of 6.7 to a mean value of 3.7 on 15 experimental day. The Listeria concentration in carrot juice samples decreased from average of 4.94 on day 5 to 3.24 log CFU/mL on day 10, and on day 15 achieved <0.01 log CFU/mL. In the compound feed trials, the pH decreased average from initial 6.5 to 3.7 on day 15. The concentration of Listeria decreased, similarly to the carrot juice samples, from average 5.0 on day 5 to 4.68 on day 10, and on day 15 achieved <0.01 log CFU/mL. In control samples, the number of Listeria increased throughout the study period and amounted to 9.2-9.84 log CFU/mL/g in all the samples. The activity of LAB has been shown to be antagonistic to L. monocytogenes. The results of the study did not show any clear differences between the used LAB strains in limiting the L. monocytogenes concentration. Based on the obtained results it can be conducted that the addition of LAB to animal food increases its microbiological safety.

Genetic evaluation of bovine papillomavirus types detected in equine sarcoids in Poland

BACKGROUND

Equine sarcoids are the most common neoplasms in horses. Bovine papilloma- virus type 1 (BPV-1) is the main viral type identified in equine sarcoids in Europe.

OBJECTIVE

The aim of the present study was to genetically evaluate BPV types based on DNA analyses of the CDS of the L1 gene. The presence of BPV DNA was confirmed by Degenerate Oligonucleotide-Primed Polymerase Chain Reaction (DOP PCR) with FAP59/FAP64 consensus primers.

RESULTS

The DNA was detected in 21/40 (52.5%) of clinically diagnosed sarcoids. More than half of 14 isolates (66.7%) shared 100% homology with BPV-1 Deltapapillomavirus 4 isolate 09 asi UK (Acc. No. MF384289) and 99% nucleotide identity with BPV-1 isolate EqSarc1 (Acc. No. JX678969). A comparison with BPV-1 isolate EqSarc1 revealed one silent mutation in C5827T which did not change the aminoacid codon. The remaining 6 isolates (28.6%) shared 100% nucleotide identity with the BPV-1 (Acc. No. X02346) "wild type" isolate, and 1 isolate (4.8%) demonstrated 99% nucleotide identity with BPV-2 (Acc. No. M20219).

CONCLUSIONS

Variants of BPV-1 isolate EqSarc1 (Acc. No. JX678969) constitute the most prevalent type of BPV-1 in Polish horses.

Pathogenic potential to humans of Shiga toxin-producing Escherichia coli isolated from wild boars in Poland

The aim of the study was to investigate the presence of Shiga toxin-producing Escherichia coli (STEC) in the wild boar population of north-eastern Poland, and to evaluate the potential health risk associated with wild boars carrying STEC/AE-STEC strains. In Poland, the African Swine Fever (ASF) virus has been a growing problem in domestic pigs and wild boars, one of the main reservoirs of the virus, because of this hunters, veterinary practitioners and foresters thus face a greater risk of coming into contact with animals. Rectal swabs samples were obtained from 152 wild boars hunter-harvested in the 2017/2018 season (autumn-winter) in north-eastern Poland. The samples were enrichment in modified buffered peptone water. Polymerase chain reaction (PCR) assays were conducted to determine the virulence profile of stx1, stx2 and eae and aggR genes, identify subtypes of stx1 and stx2 genes, and perform O and H serotyping. STEC/AE-STEC virulence genes were detected in 43 isolates (28.29%): STEC in 17 isolates (11.18%) and AE-STEC in 26 isolates (17.11%), respectively. None of the tested isolates carried the aggR gene. The most dangerous AE-STEC virulence profile associated with HUS was found in 2 isolates (1.32%): stx1NS/stx2a/d/eae serotype ONT:H7 and stx2a/eae serotype O146:H7. Six of the 152 tested samples belonged to serogroup O157 (3.95%), including one AE-STEC isolate with virulence profile stx2g/eae and five EPEC isolates. The results of this study suggest that wild boars in north-eastern Poland can carry STEC/AE-STEC strains that are potentially pathogenic for humans. This is the first report documenting the virulence of STEC and AE-STEC isolates from wild boars in Poland.

Presence of ail and ystB genes in Yersinia enterocolitica biotype 1A isolates from game animals in Poland

The pathogenicity of Yersinia enterocolitica is associated with the presence of plasmid and chromosomal virulence genes. Strains belonging to biotype 1A do not possess pYV plasmids, often harbour the ystB gene and usually lack the ail gene, which is the main virulence marker for Y. enterocolitica. The simultaneous presence of ail and ystB is uncommon. In this study, 21/218 (9.6%) biotype 1A Y. enterocolitica isolates from rectal swabs of wild boar (Sus scrofa; n = 18), red deer (Cervus elaphus; n = 2) and roe deer (Capreolus capreolus; n = 1) in Poland harboured both ail and ystB genes.

Monitoring of Yersinia enterocolitica strains from free-living animals using different methods

The aim of the study was to monitor Y. enterocolitica strains from free-living animals captured during 2011-2014 hunting seasons in Poland using warm (ITC) and cold (PSB) enrichment and molecular examination. Over 1600 samples have been cultured. After ITC/PSB enrichment 237 strains presenting features characteristic for Y. enterocolitica were isolated. Molecular examination using multiplex PCR revealed 140 isolates from PSB and 78 from ITC. The concentration of pathogenic Yersinia in asymptomatic carriers is low and the PCR detection should be preceded by bacteriological examination.

The influence of experimental Yersinia enterocolitica infection on the pregnancy course in sows--preliminary studies. III. Histopathological lesions

The aim of the study was to evaluate the anatomo- and histopathological lesions in internal organs of sows and their stillborn piglets after experimental Y. enterocolitica infection in different phases of pregnancy. Twelve pregnant sows were divided into 4 groups, infected per os on 33 (n = 3), 54 (n = 3) and 89 (n = 3) day of pregnancy with the pathogenic Y. enterocolitica strain isolated from the aborted swine fetus, and uninfected control group. Histopathological examinations of internal organs and intestine samples of stillborn piglets, slaughtered sows and samples of placentas were performed. Anatomo- and histopathological lesions were the most intense in the group of sows infected in the final phase of pregnancy, where the highest number of stillborn piglets was also found. Lesions of internal organs in stillborn piglets suggested a severe generalized bacterial infection. Although the analysis of experimental Y. enterocolitica infection of pregnant sows revealed that the most intense clinical, anatomopathological and histopathological abnormalities were recorded in the group of animals infected in the final phase of pregnancy. Infection in the first phase of pregnancy could have had an influence on the formation of the granulomatous inflammation. Differences in anatomopathological lesions between infected and control animals suggest that the period of pregnancy in which the infection appears could have had an influence on the course of yersiniosis in pigs.

Effectiveness of coupled administration of Bioimmuno immunomodulator and Respisure One vaccine in the prophylaxis of mycoplasmal pneumonia of swine

The study was aimed at determining the protective value of the coupled application of immunomodulation and vaccination in the prophylaxis of mycoplasmal pneumonia of swine (MPS). It was conducted on a pig farm, on 28 piglets with body weights of 7-8 kg in the peri-weaning period, divided into four groups of 7 animals each. In the experiment, the following were used: Bioimmuno preparation (Institute of Inland Fisheries, Olsztyn) elaborated based on methisoprinol and Saccharomyces cerevisiae, to be administered with feed, as well as an inactivated vaccine against MPS - Respisure One (Pfizer). The first two groups of piglets were administered Bioimmuno with a feed mixture at a dose of 1 kg/50 kg feed for 48 hours prior to the immunization of one of the groups with Respisure One on day 28 of life. The third group of piglets was only vaccinated, whereas the fourth group served as control. Clinical observations were conducted that covered the monitoring of side reactions (local and constitutional), an evaluation of the incidence and character of symptoms manifested by the respiratory system and other health status disorders as well as the determination of the number and percentage of medical interventions and death cases of animals. Animal husbandry examinations and post-slaughter analyses involved the determination of the mean body weight at slaughter, mean daily body weight gains, mean daily feed utilization, and mean feed conversion ratio per 1 kg b.w. gain and an index of quantitative lesions in the lungs. The study did not demonstrate any local side reactions at an injection site of the Respisure One vaccine nor any constitutional side reactions linked with the administration of either preparation. In turn, the clinical and animal husbandry examinations showed a positive effect of administering the Bioimmuno immunomodulator on the effectiveness of immunization against MPS with the Respisure One vaccine and on the improvement of the health status of pigs, which was manifested by a reduced incidence of infections in the piglets with respiratory symptoms, increased b.w. gains, improved feed utilization and shortened fattening period. Due to the diminished intensification of respiratory symptoms and pathological lesions in lungs and the improved fattening indices, the coupled administration of the Bioimmuno and Respisure One biopreparations to piglets may constitute an important element of MPS prophylaxis in pig herds.

Indices of non-specific and specific humoral immunity in pigs immunomodulated with the Bioimmuno preparation and/or immunised with the Respisure One vaccine against mycoplasmal pneumonia of swine

The purpose of the study was to determine the influence of the Bioimmuno preparation administered in feed and/or immunisation with the Respisure One vaccine on the development of selected indices of non-specific and specific humoral immune response against Mycoplasma hyopneumoniae (Mhp) infections in pigs. The study was performed on 28 piglets at the age of 4 weeks, divided into four equal groups. The biopreparations were administered according to the following pattern: group I--Bioimmuno (IFI Olsztyn, Poland) with feedstuff at amount of 1 kg/50 kg of feed for 48 h before vaccination with Respisure One (Pfizer) on day 28 of life; group II--Bioimmuno only (1 kg/50 kg feedstuff) for 48 h before vaccination with Respisure One of groups I and III; group III--Respisure One only on day 28 of life (2 ml/animal i.m.) and group C (control)--PBS (2 ml/animal i.m.) simultaneously with vaccination of groups I and III. On days 0, 3, 7, 14 and 21 after immunomodulation and/or immunisation, the serum level of gamma-globulins, the activity of lysozyme (LSM) as well as the serum levels of cytokines: interferon gamma (IFNgamma), interleukin 1 beta (IL-1beta) and interleukin 6 (IL-6) were determined, as indices of non-specific immune response against Mhp infections in pigs. The study has revealed that in piglets after weaning the application of the Bioimmuno and/or Respisure One biopreparations improves the non-specific immunity parameters stimulating an increase in serum levels of gamma-globulins, lysozyme and cytokines (IFNgamma, IL-1beta, IL-6), while late appearing seroconversion confirms a minor role of specific humoral immunity in the protection against Mhp infection.

Partial sequence analysis of the L1 gene of bovine papillomavirus type 1 detected by PCR with MY09/MY11 primers in equine sarcoids in Poland

BPV-1 is now recognized as a main etiological agent of equine sarcoids. The etiopathogenesis of the equine sarcoids is equivocal and is not yet fully understood. The aim of the present study was to analyse a partial sequence of the L1 gene of BPV associated with equine sarcoids in Polish horses. After clinical diagnosis, 40 skin lesions obtained from 29 horses were collected. The amplicons of a fragment of BPV L1 DNA were detected using PCR with MY09/MY11 primers in 31 specimens. All of them were recognized as BPV-1. Phylogenetic analysis has allowed the amplicons of partial L1 gene to be divided into 3 phylogenetic groups (A, B, C) and one separate isolate (20c). Sequence variants from phylogenetic groups B, C and isolate 20c represented new genetic variants of BPV-1 L1. Sequence variants from groups B and C were submitted to GenBank NCBI.

The influence of experimental Yersinia enterocolitica infection on the pregnancy course in sows--preliminary studies. I. Bacteriological examination

The aim of the study was to determine the influence of Yersinia enterocolitica (Y. enterocolitica) experimental infection on the carrying and shedding states of the microorganism by pregnant sows and on the bacteria occurrence in tissues of the infected animals and aborted or stillborn piglets. Twelve pregnant sows were divided into 4 groups and infected per os on 33--group I (n = 3), 54--group II (n = 3) and 89--group III (n = 3) day of pregnancy with the Y. enterocolitica strain isolated from the palatine tonsil of aborted swine fetus. The control group (n = 3) remained uninfected. Rectal, oral and vaginal swabs from sows, placentas and the specimens of tissues from stillborn piglets were collected for bacteriological examination. Eight weeks after delivery, the sows were slaughtered and samples of internal organs were subjected to bacteriological examination. Pregnancy in all groups of sows took a normal course, and no cases of abortion were observed. Y. enterocolitica was isolated from oral, rectal and vaginal swabs of all infected sows. The number of stillborn piglets in the litters was highest in group III, where two macerated fetuses with putrefactive lesions were found. The bacteria were isolated from tissues of stillborn piglets in groups I and III, and only from placenta in group II. In rectal swabs of piglets in all groups, Y. enterocolitica was not isolated. The results of experimental infection of pregnant sows with Y. enterocolitica revealed that in animals infected in the last part of pregnancy, the microorganisms were isolated most frequently from vaginal, rectal and oral swabs of sows as well as from internal organ tissues of stillborn piglets.

The influence of experimental Yersinia enterocolitica infection on the pregnancy course in sows--preliminary studies. II. Antibodies, C-reactive proteins and haptoglobin as an immunological response

The aim of the study was to determine the time of emergence and level of Y. enterocolitica antibodies in pregnant sows challenged orally with Y. enterocolitica in particular trimesters of pregnancy (groups I, II and III, respectively) and also the assignation of its influence on the CRP and Hp concentration in sera of pigs. Levels of antibodies measured by tube agglutination test increased slowly from 2 weeks post infection (wpi) and positive results were obtained not in all animals. In ELISA, in 2 weeks in all groups of infected animals high levels of antibodies against Y. enterocolitica were formed and lasted up to the end of the experiment. In newborn piglets in all groups, a significant decrease in antibody levels 6 weeks after birth was observed in both agglutination and ELISA tests. Concentrations of CRP as Hp in all groups of infected animals increased in 1 week post infection. Statistically significant differences (P < or = 0.05) between CRP levels in groups I and II (46-fold and 44-fold) as well as III (29-fold) were revealed. In case of Hp, statistically significant differences between groups of animals in the first week post infection were not observed. Our findings indicate that Y. enterocolitica infection evoked strong and long-lasting immunological reaction in the form of specific antibodies production in all inoculated animals. The significant increase in CRP and moderate increase in Hp concentrations in the sera of pregnant sows also occurred. However, relationships between colostrums antibody levels in piglets' sera and phase of pregnancy when the Y. enterocolitica infection happened in sows were not observed.

Isolation of Yersinia enterocolitica from aborted fetuses and sows in pig farms with reproductive disturbances

The purpose of the study was to determine the occurrence of Yersinia enterocolitica in tissues of aborted fetuses, placentas, vaginal and rectal swabs of aborting sows from pig farms where reproductive disturbances were found and to determine and analyze the biotype and serotype affinity of the strains isolated. Altogether 97 fetuses aborted in various stages of pregnancy, 25 placentas and swabs from 231 sows were taken. All sows originated from farms where reproductive disorders appeared. In general, 1069 samples were collected. Two enrichment methods were used in this study; fast enrichment techniques in ITC broth, then plating onto CIN agar (ITC/CIN), and cold enrichment in phosphate buffered saline followed by plating onto CIN agar (PBS/CIN). From all samples examined, 96 Y. enterocolitica strains were isolated including 57 (59.4%) from rectal swabs of sows, followed by 6 (6.3%) from vaginal swabs and 2 (2.1%) from placentas. The bacteria were isolated from tissues of 18 out of 97 aborted fetuses. A total of 60 strains were selected for further examination--29 strains originated from aborting sows and 31 from aborted fetuses. Among strains examined 54 isolates (90%) belonged to the biotype 1A of Y. enterocolitica and to the different serotypes O:3, O:5, O:6, O:7/13, O:8 and NT (not typable). Only 6 strains belonged to serotype O:3, biotype 4 Y. enterocolitica. Our study has revealed the possibility of Y enterocolitica isolation from internal organs of aborted swine fetuses and sows from farms with reproductive disturbances. The results suggest the connection between fetal death, pregnancy course disorders and Y. enterocolitica infection.

Analysis of the presence of ail, ystA and ystB genes in Yersinia enterocolitica strains isolated from aborting sows and aborted fetuses

Forty-five Yersinia enterocolitica strains isolated from aborted fetuses and placentas and from vaginal and rectal swabs of aborting sows were subjected to serotyping, biochemical typing and polymerase chain reaction multiplex analyses to detect the presence of the ail, yst A and ystB genes. The isolates were recovered from the internal organs (tonsil, lung, liver, spleen, kidney, mesentheric lymph nodes, small intestine and rectal intestine) of 18 (18.6%) of 97 aborted fetuses examined, two (8%) of 25 aborted placentas and 27 (15.8%) of 172 examined aborting sows. Serotyping of Y. enterocolitica revealed that only six (13.3%) of the examined isolates belonged to serotype O:3, with a considerable number of isolates (31.1%) having serotype O:5, while biochemical studies showed that as many as 40 of the 45 strains belonged to biotype 1A. As expected, the Y. enterocolitica strains of bioserotype 4/O:3 contained ail and ystA genes, while strains of biotype 1A contained only the ystB gene.

Role of goats in epizootiology and epidemiology of Q fever

Numerous data show that the epizootics of Q fever in goats can be particularly related to cases of this disease in humans. The aim of the study was to examine 98 goat serum samples from the farm where abortions, early parturition and parturition of weak goatlings were noted. The microaglutination method was used in this study. Serum dilution 1:8 was defined as a positive titre. The study revealed that 79.6% of serum samples were positive and numerous high titres suggested an acute form of infection. It could be supposed that Q fever was the reason of abortions in the herd. The results obtained point to the necessity of examinations for Q fever in goats, because of the possibility of infection in people who have a contact with these animals. Goats seem to be the animal species especially sensitive to C. burnetii infection. Q fever should be taken into consideration in the differential diagnosis of the goat diseases, when abortions occur.