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Zeitschriftendaten
Format
Zeitschrift
eISSN
2450-8608
Erstveröffentlichung
30 Mar 2016
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

AHEAD OF PRINT

Zeitschriftendaten
Format
Zeitschrift
eISSN
2450-8608
Erstveröffentlichung
30 Mar 2016
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

10 Artikel
Uneingeschränkter Zugang

Detection and antimicrobial resistance of Enterobacteriaceae other than Escherichia coli in raccoons from the Madrid region of Spain

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Raccoons are an invasive alien species widely distributed in the Madrid region of Spain. These animals can carry a variety of enteric bacteria with associated antimicrobial resistance, which can infect humans and livestock. However, to our knowledge, the presence of non-E. coli Enterobacteriaceae in raccoons has not been previously studied.

Material and Methods

We conducted a study to examine the species distribution of Enterobacteriaceae isolates other than E. coli, as well as their antimicrobial resistance, in the faeces of 83 raccoons in the Madrid region.

Results

We detected 12 Enterobacteriaceae isolates other than E. coli belonging to seven different species: Citrobacter freundii (1 isolate), Citrobacter gillenii (3 isolates), Citrobacter murliniae (1 isolate), Citrobacter portucalensis (2 isolates), Enterobacter hormaechei subsp. hoffmannii (1 isolate), Hafnia paralvei (2 isolates) and Raoultella ornithinolytica (2 isolates). These isolates were found in 7 of the 83 (8.4%) animals studied. To our knowledge, this study is the first report of the presence of non-E. coli Enterobacteriaceae in raccoon faeces. All isolates but one were resistant to at least one of the 14 antimicrobials tested. Resistance to ampicillin (83.3%), amoxicillinclavulanic acid (50%) and cefoxitin (33.3%) was the most frequent.

Conclusion

Our study indicates that raccoons are a potential source of infection with Enterobacteriaceae other than E. coli for humans and livestock in the Madrid region.

Schlüsselwörter

  • other than
  • raccoons
  • antimicrobial resistance
  • spp
Uneingeschränkter Zugang

Occurrence of bovine coronavirus and other major respiratory viruses in cattle in Poland

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Bovine coronavirus (BCoV) is a causative agent of enteric and respiratory diseases in cattle. Despite its importance for animal health, no data is available on its prevalence in Poland. The aim of the study was to determine the virus’ seroprevalence, identify risk factors of BCoV exposure in selected cattle farms and investigate the genetic variability of circulating strains.

Material and Methods

Serum and nasal swab samples were collected from 296 individuals from 51 cattle herds. Serum samples were tested with ELISA for the presence of BCoV-, bovine herpesvirus-1 (BoHV-1)- and bovine viral diarrhoea virus (BVDV)-specific antibodies. The presence of those viruses in nasal swabs was tested by real-time PCR assays. Phylogenetic analysis was performed using fragments of the BCoV S gene.

Results

Antibodies specific to BCoV were found in 215 (72.6%) animals. Seropositivity for BCoV was more frequent (P>0.05) in calves under 6 months of age, animals with respiratory signs coinfected with BoHV-1 and BVDV and increased with herd size. In the final model, age and herd size were established as risk factors for BCoV-seropositivity. Genetic material of BCoV was found in 31 (10.5%) animals. The probability of BCoV detection was the highest in medium-sized herds. Polish BCoVs showed high genetic homology (98.3–100%) and close relatedness to European strains.

Conclusion

Infections with BCoV were more common than infections with BoHV-1 and BVDV. Bovine coronavirus exposure and shedding show age- and herd density-dependence.

Schlüsselwörter

  • BCoV
  • BoHV-1
  • BVDV
  • serology
  • real time RT-PCR
Uneingeschränkter Zugang

Genotoxic effect of cadmium and zinc in the peripheral erythrocytes of Prussian carp (Carassius gibelio B.)

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Cadmium and zinc are often found in aquatic environment and may accumulate in living organisms. The aim of this study was to evaluate the genotoxic effect of Cd, Zn, and their binary mixture on the peripheral blood erythrocytes of Prussian carp (Carassius gibelio B.).

Material and Methods

The fish were exposed to 4.0 mg/L Cd, 4.0 mg/L Zn or a mixture of 4.0 mg/L Cd and 4.0 mg/L Zn for a period of 14, 21 or 28 days. Genotoxic effects were investigated in peripheral blood cells using the comet assay and the erythrocyte micronucleus assay.

Results

The results demonstrated that the frequencies of micronuclei (MN) and both nuclear and cellular abnormalities in erythrocytes were significantly higher in all exposure groups as compared to the control group. The fish exposed to the mixture of Cd and Zn presented the highest frequency of MN. Furthermore, there was a decrease in the frequency of MN and an increase in the occurrence of DNA integrity defects (DNA damage) with longer time of exposure to the metals studied.

Conclusion

Erythrocyte micronucleus and comet assays confirmed the genotoxicity of Cd and Zn. The results of the tests applied (which showed considerable variability) suggest the involvement of various toxicity mechanisms. Therefore, an integrative and comprehensive approach, using a set of assays for toxicity profile determination, should be adopted during ecotoxicological studies and environmental risk assessment pertaining to these elements.

Schlüsselwörter

  • genotoxicity
  • heavy metals
  • erythrocyte micronucleus assay
  • comet assay
  • Prussian carp
Uneingeschränkter Zugang

A preliminary study of the poultry body weight effect of carvacrol in litter and of carvacrol residue in organ tissue of exposed chickens

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Carvacrol is an essential oil extracted from oregano which can be used as a natural additive in poultry litter and could have a positive impact not only on production rates but also on the quality of poultry meat. The aim of this study was to evaluate the effect of the addition of carvacrol to litter on weight gain and the occurrence of residues in chicken tissues.

Material and Methods

One-day-old Ross 308 chicks were used for the study and were randomly divided into two experimental groups. For 42 days, one group was kept in a room with litter enriched with carvacrol and the second group was kept in a room with litter without carvacrol. After 42 days, the birds were sacrificed and necropsied. Carvacrol content was determined in homogenised organ tissue samples by liquid chromatography–mass spectrometry.

Results

Weekly weighing results showed that exposure to carvacrol in litter had no impact on chicken body weight. The analysis of plasma, muscle, liver and lung tissue after 42 days’ exposure clearly indicated that there were residues of carvacrol in the analysed matrices.

Conclusion

Exposure of chickens to carvacrol left residues but did not affect body weight.

Schlüsselwörter

  • carvacrol
  • essential oils
  • litter
  • liquid chromatography–mass spectrometry
  • poultry
Uneingeschränkter Zugang

Analysis of antimicrobial resistance and genetic correlations of Escherichia coli in dairy cow mastitis

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Escherichia coli is a widespread environmental pathogen frequently causing dairy cow mastitis. This bacterium is particularly capable of acquiring antimicrobial resistance, which can have severe impacts on animal food safety and human health. The objective of the study was to investigate antimicrobial resistance and genetic correlations of E. coli from dairy cow mastitis cases in northern China.

Material and Methods

Forty strains of E. coli from 196 mastitis milk samples were collected, susceptibility to 13 common antibiotics and the prevalence of resistance genes were tested in these strains, and the genetic characteristics were identified by multilocus sequence typing.

Results

The results showed that most isolates were multidrug resistant (MDR) (75%), and the resistance rates to cefazolin, trimethoprim-sulfamethoxazole and ampicillin were 77.5%, 55.0%, and 52.5%, respectively. The representative genes of the isolates were aadA (62.5%) and tet(B) (60.0%). Multilocus sequence typing showed 19 different sequence types (STs) and 5 clonal complexes (CCs) in the 40 isolates, mainly represented by ST10 and CC10. The strains of the same ST or CC showed a high level of genetic relatedness, but the characteristics of their antimicrobial resistance were markedly different.

Conclusion

Most E. coli isolates in the study were MDR strains. Some strains of the same ST or CC showed diverse resistance characteristics to common antimicrobials. Therefore, E. coli from dairy cow mastitis in northern China should be investigated to elucidate its antimicrobial resistance and genotypes.

Schlüsselwörter

  • molecular characteristics
  • antimicrobial resistance
  • genetic correlation
  • dairy cow mastitis
Uneingeschränkter Zugang

Potential risk of botulinum neurotoxin -producing clostridia occurrence in canned fish

Online veröffentlicht: 07 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Heat treatment is indispensable in fish canning to provide an acceptable shelf life. Its optimisation reduces the risk of the presence of Clostridium botulinum spores, which could potentially cause botulism cases. This study evaluated canned fish samples for botulism neurotoxin (BoNT)-producing clostridia contamination and can bulging through microbiological contaminant growth. A new analytical approach was developed for detection of such clostridia and phenotypically similar species.

Material and Methods

A total of 70 canned fish samples suspected of exhibiting bulging features were analysed. Culture methods were used to detect clostridia. The isolates obtained were evaluated on the basis of the exhibited phenotypic characteristics. Also, PCRs were used for the detection of genes determining BoNT production (non-toxic non-haemagglutinin (ntnh) genes) and the amplification of conservative 16S rDNA genes, which were Sanger sequenced. The obtained sequences were analysed using the Basic Local Alignment Search Tool.

Results

Clostridium genus species were isolated from 17 (24%) bulging and organoleptically changed samples. No ntnh genes were present in these isolates; however, sequencing confirmed the presence of C. sporogenes, a species with close affinity to C. botulinum.

Conclusion

To eliminate the threat of foodborne botulism, laboratory diagnostic techniques must detect species of the Clostridium genus and elucidate their ability to produce BoNTs. Although Clostridium botulinum is the most common cause of botulism, the possibility may not be ignored that non-pathogenic Clostridium species may acquire botulinum toxigenicity. The similarity between the isolated strains of C. sporogenes and C. botulinum should be incorporated in the optimisation of heat treatment to guarantee a sterilised, microbiologically safe product.

Schlüsselwörter

  • canned fish
  • microbiological contamination
Uneingeschränkter Zugang

Histamine content in selected production stages of fish products

Online veröffentlicht: 07 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Histamine intoxication, known as scombroid fish poisoning, is caused by the consumption of foods with high levels of histamine. This biogenic amine is formed as a result of histidine decarboxylation by bacterial decarboxylases present in food, including fish and fish products. The aim of this study was to investigate the content of histamine at different production stages of canned, marinated and smoked fish.

Material and Methods

Raw fish, semi-finished fish products, and the final products of the same production batches were collected between 2019 and 2022 from different fish production facilities in Poland. A total of 133 raw fish samples and 76 smoked fish, 54 brined fish, 39 canned fish and 18 marinated fish final products were analysed using high performance liquid chromatography with a diode array detector.

Results

Histamine was identified in 55 (17.2%) out of 320 tested samples, including 8 samples of raw fish with a histamine level above 100 mg/kg. However, no samples of fish products had histamine content above the European Union Commission limit.

Conclusion

The obtained results show that fish products on the Polish market are generally safe for consumers in regard to histamine intoxication risk.

Schlüsselwörter

  • histamine
  • fish products
  • HPLC-DAD
  • food safety
Uneingeschränkter Zugang

Proteomic analysis of tear film in canine diabetic patients with and without retinopathy

Online veröffentlicht: 07 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Diabetic retinopathy (DR) is the leading cause of blindness in human and animal patients. Early detection and treatment of the disease are important and can be facilitated by proteomic approaches providing biomarkers.

Material and Methods

Tear films were collected on Schirmer strips from 32 canine patients (12 diabetic dogs without changes in the retina, 8 diabetic dogs with signs of DR, and 12 control dogs). Two-dimensional electrophoresis was used to separate tear film proteins prior to their identification with matrix-assisted laser desorption/ionisation–tandem time-of-flight mass spectrometry and interrogation of protein function databases to find matches.

Results

Five significantly differentially expressed proteins were identified; of those, one was downregulated (2ʹ-5ʹ-oligoadenylate synthase 3) and four were upregulated in the tear film of two diabetic groups (Ras-related protein RAB-13; aldo-keto-reductase family 1 member C3; 28S ribosomal protein S31, mitochondrial; and 60S ribosomal protein L5). The differentially expressed proteins identified in the tear film were involved in signalling pathways associated with impaired protein clearance, persistent inflammation and oxidative stress.

Conclusion

The results of our study confirm that the pathological process in the retina in the course of diabetes mellitus causes changes in the tear film proteome.

Schlüsselwörter

  • proteomics
  • tear film
  • protein
  • animal model
  • diabetes mellitus
Uneingeschränkter Zugang

Vaccine-induced rabies in a red fox in Poland

Online veröffentlicht: 15 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Rabies as a zoonosis threatens public health worldwide. Several thousand people die each year of infections by the rabies virus (RABV). Oral rabies vaccination (ORV) of wildlife was successfully implemented in many European countries and led to rabies being brought under control there. In Poland, ORV was introduced in 1993 using vaccines containing an attenuated strain of the rabies virus. However, attenuated rabies viruses may have residual pathogenicity and cause the disease in target and non-target animals.

Material and Methods

A red fox carcass was tested as part of national rabies surveillance, and its brain was screened for RABV infection using two conjugates and a fluorescent antibody test (FAT). The rabies virus was isolated in mouse neuroblastoma cells by rabies tissue culture infection test (RTCIT), and viral RNA was detected by heminested reverse transcriptase PCR (hnRT-PCR) as well as by quantitative real-time RT-PCR (rtRT-qPCR). An amplicon of 600 bp was subjected to Sanger sequencing. To differentiate between vaccine and field RABV strains, PCR-restriction fragment length polymorphism (PCR-RFLP) using the Dra I, Msp I, Nla IV and Mbo II restriction endonucleases was performed.

Results

The rabies virus was detected in the fox’s brain using FAT, RTCIT and molecular tests. The PCR-RFLP revealed of vaccine-induced rabies, and full-length genome analysis showed 100% nucleotide sequence identity of the isolate with the reference sequences of Street Alabama Dufferin Bern (SAD Bern) vaccine strains and other vaccine-induced rabies virus isolates detected in animals and deposited in GenBank.

Conclusion

We detected vaccine-induced rabies for the first time in Poland in a fox during routine rabies surveillance.

Schlüsselwörter

  • fox
  • rabies
  • SAD Bern
  • vaccine-induced rabies
  • sequencing
Uneingeschränkter Zugang

Phylogenetic analysis of small ruminant lentiviruses originating from naturally infected sheep and goats from Poland based on the long terminal repeat sequences

Online veröffentlicht: 15 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Previous gag and env sequence studies placed Polish small ruminant lentiviruses (SRLVs) isolated from sheep and goats in subtypes B1, B2, A1, A5, A12, A13, A16–A18, A23, A24 and A27. This study extended the genetic/phylogenetic analysis of previously identified Polish SRLV strains by contributing long terminal repeat (LTR) sequences.

Material and Methods

A total of 112 samples were analysed. Phylogenetic analyses were carried out on the LTR fragment using the neighbour-joining, maximum likelihood, and unweighted pair group method with arithmetic mean methods.

Results

Polish caprine and ovine LTR sequences clustered within group A and grouped in at least 10 clusters (subtypes A1, A5, A12, A13, A16–A18, A23, A24 and A27). Most of the Polish strains (78%) belonged to the same subtype by the indication of the gag, env and LTR genomic regions. Discrepancies in affiliation depending on the particular sequence were observed in 24 (21%) strains, most of which came from mixed-species flocks where more than one SRLV genotype circulated. Sequences of the LTR reflected subtype-specific patterns. Several subtype-specific markers were identified, e.g. a unique substitution of T to A in the fifth position of the TATA box in A17, A27, A20 and B3.

Conclusion

This study provides valuable insights into the genetic diversity of SRLV field strains in Poland, their phylogenetic relationships and their position in the recently established SRLV classification. Our results confirmed the existence of the ten subtypes listed and the readier emergence of new SRLV variants in mixed-species flocks.

Schlüsselwörter

  • SRLV
  • maedi-visna virus
  • caprine arthritis encephalitis virus
  • phylogeny
  • LTR
10 Artikel
Uneingeschränkter Zugang

Detection and antimicrobial resistance of Enterobacteriaceae other than Escherichia coli in raccoons from the Madrid region of Spain

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Raccoons are an invasive alien species widely distributed in the Madrid region of Spain. These animals can carry a variety of enteric bacteria with associated antimicrobial resistance, which can infect humans and livestock. However, to our knowledge, the presence of non-E. coli Enterobacteriaceae in raccoons has not been previously studied.

Material and Methods

We conducted a study to examine the species distribution of Enterobacteriaceae isolates other than E. coli, as well as their antimicrobial resistance, in the faeces of 83 raccoons in the Madrid region.

Results

We detected 12 Enterobacteriaceae isolates other than E. coli belonging to seven different species: Citrobacter freundii (1 isolate), Citrobacter gillenii (3 isolates), Citrobacter murliniae (1 isolate), Citrobacter portucalensis (2 isolates), Enterobacter hormaechei subsp. hoffmannii (1 isolate), Hafnia paralvei (2 isolates) and Raoultella ornithinolytica (2 isolates). These isolates were found in 7 of the 83 (8.4%) animals studied. To our knowledge, this study is the first report of the presence of non-E. coli Enterobacteriaceae in raccoon faeces. All isolates but one were resistant to at least one of the 14 antimicrobials tested. Resistance to ampicillin (83.3%), amoxicillinclavulanic acid (50%) and cefoxitin (33.3%) was the most frequent.

Conclusion

Our study indicates that raccoons are a potential source of infection with Enterobacteriaceae other than E. coli for humans and livestock in the Madrid region.

Schlüsselwörter

  • other than
  • raccoons
  • antimicrobial resistance
  • spp
Uneingeschränkter Zugang

Occurrence of bovine coronavirus and other major respiratory viruses in cattle in Poland

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Bovine coronavirus (BCoV) is a causative agent of enteric and respiratory diseases in cattle. Despite its importance for animal health, no data is available on its prevalence in Poland. The aim of the study was to determine the virus’ seroprevalence, identify risk factors of BCoV exposure in selected cattle farms and investigate the genetic variability of circulating strains.

Material and Methods

Serum and nasal swab samples were collected from 296 individuals from 51 cattle herds. Serum samples were tested with ELISA for the presence of BCoV-, bovine herpesvirus-1 (BoHV-1)- and bovine viral diarrhoea virus (BVDV)-specific antibodies. The presence of those viruses in nasal swabs was tested by real-time PCR assays. Phylogenetic analysis was performed using fragments of the BCoV S gene.

Results

Antibodies specific to BCoV were found in 215 (72.6%) animals. Seropositivity for BCoV was more frequent (P>0.05) in calves under 6 months of age, animals with respiratory signs coinfected with BoHV-1 and BVDV and increased with herd size. In the final model, age and herd size were established as risk factors for BCoV-seropositivity. Genetic material of BCoV was found in 31 (10.5%) animals. The probability of BCoV detection was the highest in medium-sized herds. Polish BCoVs showed high genetic homology (98.3–100%) and close relatedness to European strains.

Conclusion

Infections with BCoV were more common than infections with BoHV-1 and BVDV. Bovine coronavirus exposure and shedding show age- and herd density-dependence.

Schlüsselwörter

  • BCoV
  • BoHV-1
  • BVDV
  • serology
  • real time RT-PCR
Uneingeschränkter Zugang

Genotoxic effect of cadmium and zinc in the peripheral erythrocytes of Prussian carp (Carassius gibelio B.)

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Cadmium and zinc are often found in aquatic environment and may accumulate in living organisms. The aim of this study was to evaluate the genotoxic effect of Cd, Zn, and their binary mixture on the peripheral blood erythrocytes of Prussian carp (Carassius gibelio B.).

Material and Methods

The fish were exposed to 4.0 mg/L Cd, 4.0 mg/L Zn or a mixture of 4.0 mg/L Cd and 4.0 mg/L Zn for a period of 14, 21 or 28 days. Genotoxic effects were investigated in peripheral blood cells using the comet assay and the erythrocyte micronucleus assay.

Results

The results demonstrated that the frequencies of micronuclei (MN) and both nuclear and cellular abnormalities in erythrocytes were significantly higher in all exposure groups as compared to the control group. The fish exposed to the mixture of Cd and Zn presented the highest frequency of MN. Furthermore, there was a decrease in the frequency of MN and an increase in the occurrence of DNA integrity defects (DNA damage) with longer time of exposure to the metals studied.

Conclusion

Erythrocyte micronucleus and comet assays confirmed the genotoxicity of Cd and Zn. The results of the tests applied (which showed considerable variability) suggest the involvement of various toxicity mechanisms. Therefore, an integrative and comprehensive approach, using a set of assays for toxicity profile determination, should be adopted during ecotoxicological studies and environmental risk assessment pertaining to these elements.

Schlüsselwörter

  • genotoxicity
  • heavy metals
  • erythrocyte micronucleus assay
  • comet assay
  • Prussian carp
Uneingeschränkter Zugang

A preliminary study of the poultry body weight effect of carvacrol in litter and of carvacrol residue in organ tissue of exposed chickens

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Carvacrol is an essential oil extracted from oregano which can be used as a natural additive in poultry litter and could have a positive impact not only on production rates but also on the quality of poultry meat. The aim of this study was to evaluate the effect of the addition of carvacrol to litter on weight gain and the occurrence of residues in chicken tissues.

Material and Methods

One-day-old Ross 308 chicks were used for the study and were randomly divided into two experimental groups. For 42 days, one group was kept in a room with litter enriched with carvacrol and the second group was kept in a room with litter without carvacrol. After 42 days, the birds were sacrificed and necropsied. Carvacrol content was determined in homogenised organ tissue samples by liquid chromatography–mass spectrometry.

Results

Weekly weighing results showed that exposure to carvacrol in litter had no impact on chicken body weight. The analysis of plasma, muscle, liver and lung tissue after 42 days’ exposure clearly indicated that there were residues of carvacrol in the analysed matrices.

Conclusion

Exposure of chickens to carvacrol left residues but did not affect body weight.

Schlüsselwörter

  • carvacrol
  • essential oils
  • litter
  • liquid chromatography–mass spectrometry
  • poultry
Uneingeschränkter Zugang

Analysis of antimicrobial resistance and genetic correlations of Escherichia coli in dairy cow mastitis

Online veröffentlicht: 04 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Escherichia coli is a widespread environmental pathogen frequently causing dairy cow mastitis. This bacterium is particularly capable of acquiring antimicrobial resistance, which can have severe impacts on animal food safety and human health. The objective of the study was to investigate antimicrobial resistance and genetic correlations of E. coli from dairy cow mastitis cases in northern China.

Material and Methods

Forty strains of E. coli from 196 mastitis milk samples were collected, susceptibility to 13 common antibiotics and the prevalence of resistance genes were tested in these strains, and the genetic characteristics were identified by multilocus sequence typing.

Results

The results showed that most isolates were multidrug resistant (MDR) (75%), and the resistance rates to cefazolin, trimethoprim-sulfamethoxazole and ampicillin were 77.5%, 55.0%, and 52.5%, respectively. The representative genes of the isolates were aadA (62.5%) and tet(B) (60.0%). Multilocus sequence typing showed 19 different sequence types (STs) and 5 clonal complexes (CCs) in the 40 isolates, mainly represented by ST10 and CC10. The strains of the same ST or CC showed a high level of genetic relatedness, but the characteristics of their antimicrobial resistance were markedly different.

Conclusion

Most E. coli isolates in the study were MDR strains. Some strains of the same ST or CC showed diverse resistance characteristics to common antimicrobials. Therefore, E. coli from dairy cow mastitis in northern China should be investigated to elucidate its antimicrobial resistance and genotypes.

Schlüsselwörter

  • molecular characteristics
  • antimicrobial resistance
  • genetic correlation
  • dairy cow mastitis
Uneingeschränkter Zugang

Potential risk of botulinum neurotoxin -producing clostridia occurrence in canned fish

Online veröffentlicht: 07 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Heat treatment is indispensable in fish canning to provide an acceptable shelf life. Its optimisation reduces the risk of the presence of Clostridium botulinum spores, which could potentially cause botulism cases. This study evaluated canned fish samples for botulism neurotoxin (BoNT)-producing clostridia contamination and can bulging through microbiological contaminant growth. A new analytical approach was developed for detection of such clostridia and phenotypically similar species.

Material and Methods

A total of 70 canned fish samples suspected of exhibiting bulging features were analysed. Culture methods were used to detect clostridia. The isolates obtained were evaluated on the basis of the exhibited phenotypic characteristics. Also, PCRs were used for the detection of genes determining BoNT production (non-toxic non-haemagglutinin (ntnh) genes) and the amplification of conservative 16S rDNA genes, which were Sanger sequenced. The obtained sequences were analysed using the Basic Local Alignment Search Tool.

Results

Clostridium genus species were isolated from 17 (24%) bulging and organoleptically changed samples. No ntnh genes were present in these isolates; however, sequencing confirmed the presence of C. sporogenes, a species with close affinity to C. botulinum.

Conclusion

To eliminate the threat of foodborne botulism, laboratory diagnostic techniques must detect species of the Clostridium genus and elucidate their ability to produce BoNTs. Although Clostridium botulinum is the most common cause of botulism, the possibility may not be ignored that non-pathogenic Clostridium species may acquire botulinum toxigenicity. The similarity between the isolated strains of C. sporogenes and C. botulinum should be incorporated in the optimisation of heat treatment to guarantee a sterilised, microbiologically safe product.

Schlüsselwörter

  • canned fish
  • microbiological contamination
Uneingeschränkter Zugang

Histamine content in selected production stages of fish products

Online veröffentlicht: 07 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Histamine intoxication, known as scombroid fish poisoning, is caused by the consumption of foods with high levels of histamine. This biogenic amine is formed as a result of histidine decarboxylation by bacterial decarboxylases present in food, including fish and fish products. The aim of this study was to investigate the content of histamine at different production stages of canned, marinated and smoked fish.

Material and Methods

Raw fish, semi-finished fish products, and the final products of the same production batches were collected between 2019 and 2022 from different fish production facilities in Poland. A total of 133 raw fish samples and 76 smoked fish, 54 brined fish, 39 canned fish and 18 marinated fish final products were analysed using high performance liquid chromatography with a diode array detector.

Results

Histamine was identified in 55 (17.2%) out of 320 tested samples, including 8 samples of raw fish with a histamine level above 100 mg/kg. However, no samples of fish products had histamine content above the European Union Commission limit.

Conclusion

The obtained results show that fish products on the Polish market are generally safe for consumers in regard to histamine intoxication risk.

Schlüsselwörter

  • histamine
  • fish products
  • HPLC-DAD
  • food safety
Uneingeschränkter Zugang

Proteomic analysis of tear film in canine diabetic patients with and without retinopathy

Online veröffentlicht: 07 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Diabetic retinopathy (DR) is the leading cause of blindness in human and animal patients. Early detection and treatment of the disease are important and can be facilitated by proteomic approaches providing biomarkers.

Material and Methods

Tear films were collected on Schirmer strips from 32 canine patients (12 diabetic dogs without changes in the retina, 8 diabetic dogs with signs of DR, and 12 control dogs). Two-dimensional electrophoresis was used to separate tear film proteins prior to their identification with matrix-assisted laser desorption/ionisation–tandem time-of-flight mass spectrometry and interrogation of protein function databases to find matches.

Results

Five significantly differentially expressed proteins were identified; of those, one was downregulated (2ʹ-5ʹ-oligoadenylate synthase 3) and four were upregulated in the tear film of two diabetic groups (Ras-related protein RAB-13; aldo-keto-reductase family 1 member C3; 28S ribosomal protein S31, mitochondrial; and 60S ribosomal protein L5). The differentially expressed proteins identified in the tear film were involved in signalling pathways associated with impaired protein clearance, persistent inflammation and oxidative stress.

Conclusion

The results of our study confirm that the pathological process in the retina in the course of diabetes mellitus causes changes in the tear film proteome.

Schlüsselwörter

  • proteomics
  • tear film
  • protein
  • animal model
  • diabetes mellitus
Uneingeschränkter Zugang

Vaccine-induced rabies in a red fox in Poland

Online veröffentlicht: 15 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Rabies as a zoonosis threatens public health worldwide. Several thousand people die each year of infections by the rabies virus (RABV). Oral rabies vaccination (ORV) of wildlife was successfully implemented in many European countries and led to rabies being brought under control there. In Poland, ORV was introduced in 1993 using vaccines containing an attenuated strain of the rabies virus. However, attenuated rabies viruses may have residual pathogenicity and cause the disease in target and non-target animals.

Material and Methods

A red fox carcass was tested as part of national rabies surveillance, and its brain was screened for RABV infection using two conjugates and a fluorescent antibody test (FAT). The rabies virus was isolated in mouse neuroblastoma cells by rabies tissue culture infection test (RTCIT), and viral RNA was detected by heminested reverse transcriptase PCR (hnRT-PCR) as well as by quantitative real-time RT-PCR (rtRT-qPCR). An amplicon of 600 bp was subjected to Sanger sequencing. To differentiate between vaccine and field RABV strains, PCR-restriction fragment length polymorphism (PCR-RFLP) using the Dra I, Msp I, Nla IV and Mbo II restriction endonucleases was performed.

Results

The rabies virus was detected in the fox’s brain using FAT, RTCIT and molecular tests. The PCR-RFLP revealed of vaccine-induced rabies, and full-length genome analysis showed 100% nucleotide sequence identity of the isolate with the reference sequences of Street Alabama Dufferin Bern (SAD Bern) vaccine strains and other vaccine-induced rabies virus isolates detected in animals and deposited in GenBank.

Conclusion

We detected vaccine-induced rabies for the first time in Poland in a fox during routine rabies surveillance.

Schlüsselwörter

  • fox
  • rabies
  • SAD Bern
  • vaccine-induced rabies
  • sequencing
Uneingeschränkter Zugang

Phylogenetic analysis of small ruminant lentiviruses originating from naturally infected sheep and goats from Poland based on the long terminal repeat sequences

Online veröffentlicht: 15 Nov 2022
Seitenbereich: -

Zusammenfassung

Abstract Introduction

Previous gag and env sequence studies placed Polish small ruminant lentiviruses (SRLVs) isolated from sheep and goats in subtypes B1, B2, A1, A5, A12, A13, A16–A18, A23, A24 and A27. This study extended the genetic/phylogenetic analysis of previously identified Polish SRLV strains by contributing long terminal repeat (LTR) sequences.

Material and Methods

A total of 112 samples were analysed. Phylogenetic analyses were carried out on the LTR fragment using the neighbour-joining, maximum likelihood, and unweighted pair group method with arithmetic mean methods.

Results

Polish caprine and ovine LTR sequences clustered within group A and grouped in at least 10 clusters (subtypes A1, A5, A12, A13, A16–A18, A23, A24 and A27). Most of the Polish strains (78%) belonged to the same subtype by the indication of the gag, env and LTR genomic regions. Discrepancies in affiliation depending on the particular sequence were observed in 24 (21%) strains, most of which came from mixed-species flocks where more than one SRLV genotype circulated. Sequences of the LTR reflected subtype-specific patterns. Several subtype-specific markers were identified, e.g. a unique substitution of T to A in the fifth position of the TATA box in A17, A27, A20 and B3.

Conclusion

This study provides valuable insights into the genetic diversity of SRLV field strains in Poland, their phylogenetic relationships and their position in the recently established SRLV classification. Our results confirmed the existence of the ten subtypes listed and the readier emergence of new SRLV variants in mixed-species flocks.

Schlüsselwörter

  • SRLV
  • maedi-visna virus
  • caprine arthritis encephalitis virus
  • phylogeny
  • LTR

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