-
Journal of Applied Microbiology Jul 2013Biofilm formation is important for the persistence of bacteria in hostile environments. Bacteria in a biofilm are usually more resistant to antibiotics and disinfectants...
AIMS
Biofilm formation is important for the persistence of bacteria in hostile environments. Bacteria in a biofilm are usually more resistant to antibiotics and disinfectants than planktonic bacteria. Our laboratory previously reported that low concentrations of zinc inhibit biofilm formation of Actinobacillus pleuropneumoniae. The aim of this study is to evaluate the effect of zinc on growth and biofilm formation of other bacterial swine pathogens.
METHODS AND RESULTS
To determine the effect of zinc on biofilm formation, biofilms were grown with or without zinc in 96-well plates and stained with crystal violet. At micromolar concentrations (0-250 μ mol l(-1)), zinc weakly inhibited bacterial growth and it effectively blocked biofilm formation by A. pleuropneumoniae, Salmonella Typhymurium and Haemophilus parasuis in a dose-dependent manner. Additionally, biofilm formation of Escherichia coli, Staphylococcus aureus and Streptococcus suis was slightly inhibited by zinc. However, zinc did not disperse preformed biofilms. To determine whether zinc inhibits biofilm formation when poly-N-acetylglucosamine (PGA) is present, PGA was detected with the lectin wheat germ agglutinin. Only A. pleuropneumoniae and Staph. aureus biofilms were found to contain PGA.
CONCLUSION
Zinc used at nonbactericidal concentrations can inhibit biofilm formation by several Gram-negative and Gram-positive bacterial swine pathogens.
SIGNIFICANCE AND IMPACT OF STUDY
The antibiofilm activity of zinc could provide a tool to fight biofilms, and the nonspecific inhibitory effect may well extend to other important human and animal bacterial pathogens.
Topics: Anti-Bacterial Agents; Bacteria; Bacterial Physiological Phenomena; Biofilms; Escherichia coli; Staphylococcus aureus; Zinc
PubMed: 23509865
DOI: 10.1111/jam.12197 -
Frontiers in Veterinary Science 2021() is one major bacterial porcine respiratory tract pathogen causing disease outbreaks worldwide, although effective commercial vaccines are available. Due to frequent...
Coinfections and Phenotypic Antimicrobial Resistance in Strains Isolated From Diseased Swine in North Western Germany-Temporal Patterns in Samples From Routine Laboratory Practice From 2006 to 2020.
() is one major bacterial porcine respiratory tract pathogen causing disease outbreaks worldwide, although effective commercial vaccines are available. Due to frequent failure of this preventive measure, treatment with antimicrobials is indispensable to prevent animal losses within an outbreak situation. To preserve the effectivity of antimicrobial substances to fight should therefore be the primary aim of any interventions. In this study, the temporal development of antimicrobial resistance in was analyzed retrospectively in the time period 2006-2020 from a routine diagnostic database. In parallel, frequent coinfections were evaluated to identify most important biotic cofactors as important triggers for disease outbreaks in endemically infected herds. The proportion of serotype 2 decreased over time but was isolated most often from diseased swine (57% in 2020). In ~1% of the cases, was isolated from body sites outside the respiratory tract as brain and joints. The lowest frequencies of resistant isolates were found for cephalothin and ceftiofur (0.18%), florfenicol (0.24%), tilmicosin (2.4%), tiamulin (2.4%), enrofloxacin (2.7%), and spectinomycin (3.6%), while the highest frequencies of resistant isolates were found for gentamicin (30.9%), penicillin (51.5%), and tetracycline (78.2%). For enrofloxacin, tiamulin, tilmicosin, and tetracycline, significantly lower frequencies of resistant isolates were found in the time period 2015-2020 compared to 2006-2014, while gentamicin-resistant isolates increased. In summary, there is only a low risk of treatment failure due to resistant isolates. In maximum, up to six coinfecting pathogens were identified in pigs positive for . Most often pigs were coinfected with Porcine Circovirus 2 (56%), (24.8%), or the Porcine Reproductive and Respiratory Syndrome Virus (23.3%). Potential synergistic effects between these pathogens published from experimental findings can be hypothesized by these field data as well. To prevent disease outbreaks in endemically infected herds more efficiently in the future, next to environmental trigger factors, preventive measures must also address the coinfecting agents.
PubMed: 35155648
DOI: 10.3389/fvets.2021.802570 -
PloS One 2019It is generally difficult to specify the sources of infection by which domestic animals may acquire pathogens. Through 16S rRNA gene amplicon sequencing, we compared the...
It is generally difficult to specify the sources of infection by which domestic animals may acquire pathogens. Through 16S rRNA gene amplicon sequencing, we compared the composition of microbiota in the saliva, vaginal mucus, and feces of pigs, and in swabs of feeder troughs and water dispensers collected from pig farms in Vietnam. The composition of the microbiota differed between samples in each sample group. Streptococcus, Actinobacillus, Moraxella, and Rothia were the most abundant genera and significantly discriminative in saliva samples, regardless of the plasticity and changeability of the composition of microbiota in saliva. Moreover, species assignment of the genus Streptococcus revealed that Streptococcus suis was exceptional in the salivary microbiota, due to being most abundant among the streptococcal species and sharing estimated proportions of 5.7%-9.4% of the total bacteria in saliva. Thus, pig oral microbiota showed unique characteristics in which the major species was the pig pathogen. On the other hand, β-diversity analysis showed that the microbiota in saliva was distinct from those in the others. From the above results, pig saliva was shown to be the major natural habitat of S. suis, and is suggested to be the most probable source of S. suis infection.
Topics: Animals; Base Sequence; Biodiversity; Ecosystem; Feces; Female; Microbiota; Phylogeny; RNA, Ribosomal, 16S; Saliva; Species Specificity; Streptococcus suis; Swine; Vagina
PubMed: 31017953
DOI: 10.1371/journal.pone.0215983 -
The Journal of Biological Chemistry Apr 2011Pathogenic bacteria acquire the essential element iron through specialized uptake pathways that are necessary in the iron-limiting environments of the host. Members of...
Pathogenic bacteria acquire the essential element iron through specialized uptake pathways that are necessary in the iron-limiting environments of the host. Members of the Gram-negative Neisseriaceae and Pasteurellaceae families have adapted to acquire iron from the host iron binding glycoprotein, transferrin (Tf), through a receptor complex comprised of transferring-binding protein (Tbp) A and B. Because of the critical role they play in the host, these surface-exposed proteins are invariably present in clinical isolates and thus are considered prime vaccine targets. The specific interactions between TbpB and Tf are essential and ultimately might be exploited to create a broad-spectrum vaccine. In this study, we report the structure of TbpBs from two porcine pathogens, Actinobacillus pleuropneumoniae and suis. Paradoxically, despite a common Tf target, these swine related TbpBs show substantial sequence variation in their Tf-binding site. The TbpB structures, supported by docking simulations, surface plasmon resonance and hydrogen/deuterium exchange experiments with wild-type and mutant TbpBs, explain why there are structurally conserved elements within TbpB homologs despite major sequence variation that are required for binding Tf.
Topics: Actinobacillus pleuropneumoniae; Actinobacillus suis; Amino Acid Sequence; Bacterial Proteins; Binding Sites; Crystallography, X-Ray; Molecular Sequence Data; Mutation; Protein Binding; Protein Structure, Secondary; Protein Structure, Tertiary; Sequence Homology, Amino Acid; Surface Plasmon Resonance; Transferrin-Binding Protein B
PubMed: 21297163
DOI: 10.1074/jbc.M110.206102 -
Veterinary Sciences Aug 2023This study aimed to determine the prevalence of bacterial diseases in pig farms in various regions of Zhejiang Province and surrounding areas. A total of 526 samples...
This study aimed to determine the prevalence of bacterial diseases in pig farms in various regions of Zhejiang Province and surrounding areas. A total of 526 samples were collected from 85 pig farms in Zhejiang Province and surrounding areas. In this study, samples were analyzed using bacterial isolation and purification, Gram staining, PCR amplification, and antimicrobial susceptibility testing. A total of 36 () isolates were detected, with an isolation rate of 6.84%; 37 () isolates were detected, with an isolation rate of 7.03%; 60 () isolates were detected, with an isolation rate of 11.41%; 170 () isolates were detected, with an isolation rate of 32.32%; 67 () isolates were detected, with an isolation rate of 12.74%; 44 () isolates were detected, with an isolation rate of 8.37%; and 7 () isolates were detected, with an isolation rate of 1.33%. Antimicrobial drug susceptibility testing against 21 types of antibiotics was carried out on the isolated strains, and the results showed that 228 strains had varying degrees of resistance to 21 antibiotics, including , , , and , with the highest resistance to lincomycin, at 100%. and were the most sensitive to cephalothin, with resistance rates of 0. In terms of strains, had the highest overall sensitivity to 21 antibiotics, and had the highest resistance. In short, bacterial diseases in Zhejiang and the surrounding areas were harmful, and the drug resistance situation was severe. This study provides scientific guidance for the clinical treatment of bacterial diseases.
PubMed: 37624289
DOI: 10.3390/vetsci10080502 -
Journal of Clinical Microbiology Jun 2015We report the first human case of meningitis and sepsis caused in a child by Actinobacillus suis or A. equuli, a common opportunistic pathogen of swine or horses,...
We report the first human case of meningitis and sepsis caused in a child by Actinobacillus suis or A. equuli, a common opportunistic pathogen of swine or horses, respectively. Identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and real-time PCR assay. A previous visit to a farm was suspected as the source of infection.
Topics: Actinobacillus Infections; Actinobacillus equuli; Actinobacillus suis; Adolescent; Bacteremia; Humans; Male; Meningitis, Bacterial; Molecular Typing
PubMed: 25878346
DOI: 10.1128/JCM.00339-15 -
Canadian Journal of Veterinary Research... Jan 2015Feral swine (Sus scrofa) are widely distributed in the United States. In 2011 and 2012, serum samples and tonsils were recovered from 162 and 37 feral swine,...
Feral swine (Sus scrofa) are widely distributed in the United States. In 2011 and 2012, serum samples and tonsils were recovered from 162 and 37 feral swine, respectively, in the US to evaluate exposure to important swine endemic pathogens. Antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) were found in 2.5% and 25.3% of tested sera, respectively. Positive serological reactions against Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae have been detected in 19.7% and 69.7% of animals. More than 15% of animals presented antibodies against these 2 pathogens simultaneously. Most animals were also seropositive for Lawsonia intracellularis. Feral swine can also be involved in transmission of zoonotic agents. Almost 50% of animals possessed antibodies against Salmonella. In addition, 94.4% of animals were carriers of Streptococcus suis in their tonsils. In conclusion, feral swine may be considered as a potential reservoir for different endemic diseases in domestic pigs, as well as for important zoonotic agents.
Topics: Animals; Animals, Wild; Antibodies, Bacterial; Antibodies, Viral; Disease Reservoirs; Seroepidemiologic Studies; Sus scrofa; Swine; Swine Diseases; United States; Zoonoses
PubMed: 25673913
DOI: No ID Found -
Canadian Journal of Comparative... Apr 1985During serological screening of a closed SPF-herd free of pleuropneumonia, more than half of the pigs were positive for complement-fixing antibodies to Haemophilus...
During serological screening of a closed SPF-herd free of pleuropneumonia, more than half of the pigs were positive for complement-fixing antibodies to Haemophilus pleuropneumoniae. Actinobacillus bacteria closely related to A. suis were isolated from tonsillar tissue of 14 out of 20 slaughtered pigs submitted for pathological and bacteriological evaluation. None of the pigs had evidence of respiratory disease. Two pigs inoculated endobronchially with a selected Actinobacillus strain developed mild focal pneumonia and complement-fixing antibodies cross-reacting with H. pleuropneumoniae. Five pigs exposed and vaccinated with the Actinobacillus strain and five pigs spontaneously infected with the strain also developed complement-fixing antibodies against H. pleuropneumoniae and appeared to be less susceptible to experimental Haemophilus pleuropneumonia than pigs not exposed to the Actinobacillus infection. The agglutination test applied on serum treated with 2-mercaptoethanol detected antibodies against H. pleuropneumoniae serotype 5 but not against serotype 1 in pigs exposed to the Actinobacillus strain. Antibodies reactive with the Actinobacillus strain were also found in pigs hyperimmunized against H. pleuropneumoniae serotypes 1-5 in 2-mercaptoethanol tube agglutination test and rabbits hyperimmunized against serotypes 1,2 and 7, and strain 73567 in the immunodiffusion test. Conversely rabbits immunized against the Actinobacillus strain had antibodies against H. pleuropneumoniae serotypes 1, 3, 4, 5 and 6. It is concluded that pigs infected with Actinobacillus organisms may become false positive reactors against H. pleuropneumoniae.
Topics: Actinobacillus; Actinobacillus Infections; Agglutination Tests; Animals; Antibodies, Bacterial; Antigens, Bacterial; Complement Fixation Tests; Cross Reactions; Haemophilus; Immunodiffusion; Lung; Palatine Tonsil; Swine; Swine Diseases
PubMed: 3926287
DOI: No ID Found -
Journal of Clinical Microbiology Nov 1991We describe the isolation of Actinobacillus lignieresii and an A. equuli-like bacterium from an infected horse-bite wound in a 22-year-old stable foreman and A. suis...
We describe the isolation of Actinobacillus lignieresii and an A. equuli-like bacterium from an infected horse-bite wound in a 22-year-old stable foreman and A. suis from a bite injury in a 35-year-old man who had been attacked by a horse. A. lignieresii was also isolated in pure culture from an infected sheep-bite wound in a rural worker. These species of the genus Actinobacillus are primarily associated with animals and animal diseases and are rarely isolated from humans. The purpose of this report is to raise awareness of the possible occurrence of Actinobacillus spp. in bite wounds inflicted by farm animals and to discuss the difficulties encountered in the identification of species of Actinobacillus and related bacteria.
Topics: Actinobacillus; Actinobacillus Infections; Adult; Animals; Bites and Stings; Horses; Humans; Male; Sheep; Wound Infection
PubMed: 1774260
DOI: 10.1128/jcm.29.11.2535-2538.1991 -
Infection and Immunity Jun 1992RTX cytolysins are a family of calcium-dependent, pore-forming, secreted toxins found in a variety of gram-negative bacteria. The prototypical member of this family is...
RTX cytolysins are a family of calcium-dependent, pore-forming, secreted toxins found in a variety of gram-negative bacteria. The prototypical member of this family is the alpha-hemolysin of Escherichia coli. The RTX genetic determinants from seven members of the family Pasteurellaceae, Pasteurella haemolytica, Actinobacillus actinomycetemcomitans, and A. pleuropneumoniae serotypes 1,5,7, and 9 were previously cloned and sequenced. Using the leukotoxin determinant from P. haemolytica serotype A1 as a probe, we detected the presence of RTX-type determinants in Actinobacillus suis, A. equuli, and A. lignieresii of the family Pasteurellaceae. All three species elaborate proteins of approximately 104 to 110 kDa that are recognized by polyclonal antisera against the 104-kDa hemolysin of A. pleuropneumoniae serotype 1. An RTX determinant of A. suis isolate 3714 was cloned and sequenced and was found to be almost identical to the RTX determinant of A. pleuropneumoniae serotypes 5 and 9. In addition, the determinant is not composed of four contiguous genes, as had been reported for most other RTX determinants; instead, the genes encoding the two proteins responsible for secretion of the toxin are at a locus distinct from that containing the toxin structural and activation genes.
Topics: Actinobacillus; Amino Acid Sequence; Animals; Bacterial Toxins; Base Sequence; Blotting, Southern; Blotting, Western; Cloning, Molecular; Cytotoxins; Hemolysin Proteins; Hemolysis; Humans; Molecular Sequence Data
PubMed: 1587585
DOI: 10.1128/iai.60.6.2166-2173.1992