Histopathological and microbiological study of porcine lymphadenitis: contributions to diagnosis and control of the disease

Causes of Condemnations of Edible Parts of Slaughtered Pigs in Bavaria and Their Economic Implications: A Retrospective Survey (2021-2022)

This study aimed to provide insights into the main causes of postmortem carcass and organ condemnations in a pig slaughterhouse and evaluate the resulting financial impact of the rejection of edible parts of animals. A population of 307,866 pigs, admitted for slaughter between January 2021 and December 2022 in a Bavarian abattoir, was studied. Regarding the examined carcasses, 2.09% (n = 6422) presented pathological conditions. Of these, 8.12% (n = 522) and 91.88% (n = 5900) were totally and partially confiscated, respectively. The main reason for the complete rejection of carcasses was the occurrence of generalized diseases (62.6%), while the presence of abscesses and traumatic and/or tail lesions was the most frequently implicated (70.7%) in partial condemnations. In the case of the organs, 17.59% (n = 54,145) presented abnormalities, with distributions of 14.71% (n = 45,290), 1.94% (n = 5968), 0.72% (n = 2213), and 0.22% (n = 674) within the examined liver, lung, kidney, and heart specimens, respectively. The principal reasons for liver, lung, kidney, and heart condemnations were the occurrence of parasitic diseases (53.4%), bacterial/viral infections (63.5%), dystrophies/anomalies (98.4%), and bacterial/viral infections (98.5%), respectively. The total financial loss attributable to carcass and organ condemnations was estimated at EUR 392,744.2, which represents 0.40% of the total achievable net revenue without rejections. Of this, EUR 197,120 (0.20%) and EUR 195,624.2 (6.95%) were related to carcass and offal seizures, respectively. The study results offer useful information for veterinarians, stockowners, and epidemiologists to make and set up policies to increase the efficiency and benefits of the swine production system and protect public health.

Peri-implantitis with a potential axis to brain inflammation: an inferential review

Peri-implantitis (PI) is a chronic, inflammatory, and infectious disease which affects dental implants and has certain similarities to periodontitis (PD). Evidence has shown that PD may be related to several types of systemic disorders, such as diabetes and insulin resistance, cardiovascular diseases, respiratory tract infections, adverse pregnancy outcomes, and neurological disorders. Furthermore, some types of bacteria in PD can also be found in PI, leading to certain similarities in the immunoinflammatory responses in the host. This review aims to discuss the possible connection between PI and neuroinflammation, using information based on studies about periodontal disorders, a topic whose connection with systemic alterations has been gaining the interest of the scientific community. Literature concerning PI, PD, and systemic disorders, such as neuroinflammation, brain inflammation, and neurological disorder, was searched in the PubMed database using different keyword combinations. All studies found were included in this narrative review. No filters were used. Eligible studies were analyzed and reviewed carefully. This study found similarities between PI and PD development, maintenance, and in the bacterial agents located around the teeth (periodontitis) or dental implants (peri-implantitis). Through the cardiovascular system, these pathologies may also affect blood-brain barrier permeability. Furthermore, scientific evidence has suggested that microorganisms from PI (as in PD) can be recognized by trigeminal fiber endings and start inflammatory responses into the trigeminal ganglion. In addition, bacteria can traverse from the mouth to the brain through the lymphatic system. Consequently, the immune system increases inflammatory mediators in the brain, affecting the homeostasis of the nervous tissue and vice-versa. Based on the interrelation of microbiological, inflammatory, and immunological findings between PD and PI, it is possible to infer that immunoinflammatory changes observed in PD can imply systemic changes in PI. This, as discussed, could lead to the development or intensification of neuroinflammatory changes, contributing to neurodegenerative diseases.

The Genetic Diversity and Antimicrobial Resistance of Pyogenic Pathogens Isolated from Porcine Lymph Nodes

According to the Food and Agriculture Organization of the United Nations, pork remains the most consumed meat in the world. Consequently, it is very important to ensure that it is of the highest microbiological quality. Many of the pathogens that cause lymph node lesions in pigs are zoonotic agents, and the most commonly isolated bacteria are Mycobacterium spp., Streptococcus spp., Staphylococcus aureus and Rhodococcus equi (synonymous with Prescottella equi). The prevention and treatment of zoonotic infections caused by these bacteria are mainly based on antimicrobials. However, an overuse of antimicrobials contributes to the emergence and high prevalence of antimicrobial-resistant strains, which are becoming a serious challenge in many countries. The aim of this study was to evaluate the genetic diversity and antimicrobial resistance of the Streptococcus spp. (n = 48), S. aureus (n = 5) and R. equi (n = 17) strains isolated from swine lymph nodes with and without lesions. All isolates of S. dysgalactiae, S. aureus and R. equi were subjected to PFGE analysis, which showed the genetic relatedness of the tested bacteria in the studied pig populations. Additionally, selected tetracycline and macrolide resistance genes in the streptococcal strains were also studied. The results obtained in the present study provide valuable data on the prevalence, diversity, and antimicrobial resistance of the studied bacteria. Numerous isolated bacterial Streptococcus spp. strains presented resistance to doxycycline, and almost half of them carried tetracycline resistance genes. In addition, R. equi and S. aureus bacteria presented a high level of resistance to beta-lactam antibiotics and to cefotaxime, respectively.

Additional post-mortem inspection procedures and laboratory methods as supplements for visual meat inspection of finishing pigs in Europe—Use and variability

In the EU, a post-mortem inspection of finishing pigs comprises visual inspections of the carcass and offal followed by additional examinations, such as palpation and incision of parts, when needed. Moreover, it can include various laboratory tests. Since European meat inspection is regulated by the EU, one may assume that post-mortem inspection is performed in the same way in the Member States. However, previous studies showed that variations exist. This article shows the results of a survey performed in September 2020 on how visual meat inspection of finishing pigs is applied in Europe. By using a questionnaire, palpations, incisions and other procedures for 10 gross pathological findings and laboratory methods applied by official veterinarians to evaluate the fitness of meat for human consumption were assessed. We received 44 responses from 26 European countries. Most respondents reported that visual meat inspection was a generally applied inspection method. The main reason for not applying visual meat inspection was export requirements. The most important reasons for applying palpations and incisions in addition to visual inspection were findings detected in ante- or post-mortem inspection. There was considerable variation in the use of palpations and incisions, other post-mortem procedures and laboratory tests to assess meat fitness for human consumption. The respondents mentioned some country-specific practices, but we also observed variations within the responding official veterinarians that could not be explained by country of origin or years of work experience. Additional detailed studies on the variation are needed before harmonisation of meat inspection procedures are attempted.

Prevalence and Genetic Diversity of Trueperella pyogenes Isolated from Infections in European Bison (Bison bonasus)

Simple Summary

In the European bison, Trueperella pyogenes is associated with different suppurative infections of mainly the urogenital tract or with abscesses in various tissues. Our research showed that in the studied population of European bison in Poland, the prevalence of T. pyogenes infections is relatively high. The significant genetic diversity of isolated strains was observed. However, in a few cases, the same RAPD profile was obtained for strains isolated from individuals living in the same area. Our study indicated that different virulence factors are related to the pathogenicity of this bacterium. The results obtained in this study provide valuable data about the prevalence, pathogenicity and genetic diversity of T. pyogenes in the European bison. Thus, it improves the knowledge on treatment for the European bison’s health and proves the importance of continuous monitoring for the protection of these wild ruminants.

Abstract

Trueperella pyogenes is a Gram-positive bacterium causing purulent infections in many animal species, including the European bison. However, the data about the virulence and genetic relationships of T. pyogenes strains isolated from these wild ruminants are strongly limited. The aim of this study was to investigate the prevalence of T. pyogenes infections in the European bison, and to evaluate the genetic diversity of isolates from these animals. In the time span of 10 years, 328 European bison from 16 different locations were examined. The standard bacteriological methods were used for T. pyogenes isolation and identification from clinical specimens obtained from urogenital tract infections and abscesses of different locations. The presence of genes encoding known virulence factors was investigated by PCR, and the genetic diversity of T. pyogenes strains was examined with the RAPD-PCR method. The prevalence of T. pyogenes infections was 14.6%, and the pathogen was isolated from both female (47.9% of isolates) and male (52.1% of isolates) European bison. It should be highlighted that a considerable number of strains were isolated from the prepuce and penis infections. Therefore, the role of T. pyogenes in the pathogenesis of balanoposthitis should be seriously perceived. A total of 39 T. pyogenes strains were subjected to genetic characterization. All studied strains carried the plo gene, while the nanH (25.6%), nanP (23.1%), cbpA (7.7%), fimA (97.4%), fimC (69.2%), fimE (92.3%) and fimG (15.4%) genes were present with a variable frequency among the tested strains. The virulence genotype plo/fimA/fimC/fimE was dominant. RAPD-PCR typing showed a high level of genetic diversity among European bison T. pyogenes strains, and a total of 31 different RAPD profiles were distinguished. In a few cases, the same RAPD profile was found in strains obtained from animals living in the same area. This study provided the first data about the prevalence and genetic relationships of T. pyogenes in the Polish population of European bison. However, further epidemiological investigations are needed to understand the routes of transmission and dissemination of the pathogen in these wild animals.

RAPD-PCR-Based Fingerprinting Method as a Tool for Epidemiological Analysis of Trueperella pyogenes Infections

In this study, a Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) method for genetic typing of Trueperella pyogenes, an opportunistic bacterial pathogen, was designed. The method optimization was performed for 37 clinical T. pyogenes strains isolated from various infections in different animal species. Optimal conditions for reliable and reproducible DNA fingerprinting were determined according to the modified Taguchi method. The developed method was assessed regarding its typeability, reproducibility, and discriminatory power using the Hunter’s and Gatsons’ index of discrimination. A high degree of genetic diversity was shown between the studied strains, which represented 31 genotypes. The generated RAPD profiles were relatively complex and simultaneously easy to interpret due to the wide size range of amplicons. The discriminatory index of the designed method was sufficiently high; thus, only strains epidemiologically related displayed identical RAPD genotypes. In conclusion, the DNA fingerprinting of T. pyogenes by the developed RAPD-PCR method is a reliable typing tool that may allow a better understanding of the epidemiology as well as pathogenesis of infections caused by this pathogen.