Corynebacterium Pseudotuberculosis Research Articles

Interferon gamma kinetics associated with immunodiagnostic techniques in experimental goats infected with biofilm producer and non-biofilm producer strains of Corynebacterium pseudotuberculosis

Caseous lymphadenitis can be diagnosed using serological tests, mainly the enzyme-linked immunosorbent assay (ELISA). In this work, we evaluated interferon-gamma production in goats infected and not infected with Corynebacterium pseudotuberculosis, correlating it with the ELISA diagnostic test and analyzing the cellular and humoral responses, respectively. Eighteen Canindé goats experimentally infected with biofilm-producing and non-biofilm-producing strains were used. The sensitivity of the antigens was above 80%, with seroconversion observed from 14 days post-infection. A significant band between 64 and 70 kDa was shown in Western blotting. The production of IFN-y shows a tendency towards greater production in goats infected with the biofilm-producing strain stimulated by the TPP antigen of the same strain. The results help better understand the cellular and humoral response and antigenicity of the strains under study, correlated with the production of IFN-y, which plays a vital role in infection.

Isolation and Molecular Characterization of Corynebacterium pseudotuberculosis from Goats in Andaman and Nicobar Islands, India

Caseous lymphadenitis (CLA), caused by the bacteria Corynebacterium pseudotuberculosis, is a highly contagious disease of small ruminants, especially of goats and sheep. Here, we report an outbreak of the disease in goats for the first time from the Andaman and Nicobar Islands along with isolation and molecular characterization of the pathogen. A total of 22 goats were affected, with an attack rate of 12.02%, and six isolates were identified from the clinical samples. Molecular characterization of the pathogen was carried out based on the sequence information of 16S rRNA and RNA polymerase β subunit (rpoB) gene fragments. rpoB-based phylogenetic analysis indicated that the isolates belonged to Corynebacterium pseudotuberculosis biovar ovis. The antimicrobial resistance study revealed that the isolates were 100% resistant against erythromycin and rifampicin. Fifty percent resistance was found against amoxicillin/clavulanic acid, ciprofloxacin, penicillin, and vancomycin. All the isolates were sensitive to tetracycline, chloramphenicol, cotrimoxazole, sulphafurazole, ampicillin/cloxacillin, and oxytetracycline. In conclusion, the present study reports the occurrence of CLA in goats for the first time from an isolated archipelago of India and unveils the molecular signature and antibiotic resistance patten of the pathogen. The findings of this study will be helpful to control or eradicate the disease from the Andaman and Nicobar Islands.

A Molecular Approach to Understand the Involvement of Mycoplasma in Suppurative Otitis Cases of Cattle in Chittoor District of Andhra Pradesh

In bovines the economic losses mainly due to the outbreak of diseases, leads to mortality, morbidity, treatment cost and reduced production. Recently in August month of 2024, received 13 bovine suppurativeotitis samples from outbreak in KuppamMandal of Chittoor district. The history having the purulent discharges with foul smell from ear infections of cattle that to crossbreed cattle of all age groups are affected. After 5 days of appearing aural discharges the animals were also shown the nervous signs, head tilting and other clinical findings includes unilateral or bilateral ear droop, epiphora, ptosis, abnormal nystagmus, strabismus, regurgitation, stiff neck, opisthotonus, facial hyperesthesia, purulent aural discharge, nasopharyngeal collapse, recumbency and finally death were noticed in severely affected animals. All the samples were processed for cultural tests by inoculating in PPLO selective broth and selective media PPLO agar then incubated anaerobically at 370C and observed the color development in broth pink to yellow color after 3- 5 days of incubation indicative of positive growth and fried egg micro colonies on selective PPLO agar media after 8-14 days of incubation observed under low power and 40X. The DNA was isolated from all the samples and screened for presence of Mycoplasma by targeting 16s rRNA gene and found that out of 13 samples 10 were positive for genus Mycoplasma and produced the predicted 280bp size product in all positive samples. The suppurativeotitis in cattle usually is caused by Actinomyces spp., Corynebacterium pseudotuberculosis, E. coli, Heamophilus, P.multocida, Pseudomonas spp, Streptococcus spp., and Mycoplasma bovis. This study was targeted only the emerging pathogen i.e the cellwall deficient bacteria Mycoplasma because of infections is hampered by a lack of effective vaccines and specific treatments, leads to increasing trends in antimicrobial resistance. Concluded that isolation and identification of the pathogenic ........

Caseous Lymphadenitis in sheep and goats – “Cheese Glands”

Caseous lymphadenitis (CLA) is a chronic infectious disease that affects small ruminants and is caused by Corynebacterium pseudotuberculosis. This highly contagious pathogen leads to significant economic losses in the livestock industry due to loss of productivity, rejection of carcasses, and increased veterinary costs. CLA is characterised by the formation of abscesses in lymph nodes and internal organs. Rupture of these nodes can lead to additional contamination of the environment and further transmission. Diagnosis of CLA involves clinical examination, bacterial cultures, serological testing, and advanced molecular techniques for more accurate detection. Treatment options are limited and often ineffective as the pathogen can survive in abscesses and evade the host's immune response. Antibiotic therapy can provide temporary relief but does not eliminate infection, emphasising the importance of prevention measures. Control strategies focus on biosecurity, culling infected animals, and vaccination. While currently available vaccines reduce the incidence and severity of the disease, they do not provide complete immunity and need to be further improved. Understanding the virulence mechanisms of the pathogen and the interactions between the host and pathogen is crucial for the development of more effective vaccines and therapeutic approaches. Ongoing research and new ideas are crucial to reduce the impact of CLA on animal health and the farm economy. This emphasises the need for comprehensive management strategies, including strict hygiene measures, regular checks, and targeted vaccination plans. In addition, due to its zoonotic potential, C. pseudotuberculosis can contaminate meat and milk from infected animals, posing a risk to consumers. The ability of the pathogen to infect both animals and humans emphasises the importance of research into its prevention and diagnosis.

The effect of the nisin-based pharmaceutical formulation used in the treatment plan for cows with subclinical mastitis on the milk microbiota

Due to the growing threat of antimicrobial resistance, the search and development of new drugs to treat infectious mammary gland diseases of high yielding cows is an urgent task. The paper presents data on the microbiota composition of milk from high yielding cows suffering from subclinical mastitis; 144 microbial isolates were recovered from 70 milk samples; with the highest number of Staphylococcus aureus and Streptococcus dysgalactiae detected (22.2 and 16.0%, respectively). The study showed that a significant number of Staphylococcus aureus isolates (53.1%) were resistant to I generation cephalosporins; 52.6% of the isolated Streptococcus dysgalactiae strains showed resistance to tetracyclines; 33.3% of Staphylococcus haemolyticus isolates were resistant to macrolides. 42.1; 35.3 and 62.5% of Enterococcus faecium, Aerococcus viridans and coliform bacteria isolates, respectively, were resistant to penicillins. 38.5% of Staphylococcus epidermidis isolates were found to be resistant to tetracyclines. Corynebacterium pseudotuberculosis isolates showed equal resistance to penicillin and tetracycline antimicrobials (20.0%). The research revealed presence of multi-drug resistant coliform bacteria, Streptococcus dysgalactiae, Aerococcus viridans, Staphylococcus aureus strains. Experiments to study the effect of the new nisin-based pharmaceutical formulation on microbiota of milk from cows with subclinical mastitis were carried out using 35 high yielding cows. A microbiological testing of cow milk on day 14 from the beginning of the treatment showed that the number of microbiota-free samples increased to 88.6%, while in 1.4% of cases Staphylococcus aureus isolates were recovered (103 CFU/mL). The titers of coliform and Staphylococcus aureus bacteria isolated in 1.4% (101 CFU/mL) and 2.7% (102 CFU/mL) of cases, respectively, were not etiologically significant.

Prevalence Of Some Pyogenic Organisms In Skin Wound Infections In Sheep And Goat

Background: Pyogenic bacterial infections are broadly found worldwide among sheep and goats and are adversely impacting the development of the small ruminants’ industry. The study was performed to identify and characterize most prevalent bacteria isolated from skin and wound infections of sheep and goat of various rearing condition in Egypt. Materials and Methods: One hundred and fifteen pus samples (sheep≈70) and (goat≈45) obtained from skin abscesses and pyogenic wounds during the study period 2022-2023. The samples were cultured onto suitable media, microscopically and biochemically tested. The obtained isolates were assessed for their antibiotic susceptibility and subjected to polymerase chain reaction to detect certain genes which responsible for the virulence and antibiotic resistance. Results: Bacterial isolates were recovered from 83 out of the 115 collected pus samples (72.17%) with pure isolation were obtained in 68 cultures. The bacterial isolation was achieved in 88.57% and 46.66% from sheep and goat respectively. Pseudomonas aeruginosa were recovered as 19.35% from sheep and 23.81% from goat while Staphylococcus aureus were isolated as 46.77% and 38.09% from sheep and goat respectively. Regarding Corynebacterium pseudotuberculosis was obtained from 37.09% of sheep and 9.52% of goat samples. P. aeruginosa isolates were highly sensitive to erythromycin, amikacin, ampicillin /sulbactam and cefoxitin and high resistance to amoxicillin /clavulanic acid, clindamycin, and quinolones with 58.82% MDR pattern. S. aureus isolates revealed the high sensetivity to amikacin, imipenem and clindamycin but high resistant to quinolones with 21.62% act as MDR. C. pseudotuberculosis isolates were sensitive to most of tested antibiotics except amoxicillin /clavulanic acid and clindamycin. PCR assays revealed that P. aeruginosa isolates carried toxA and blaOXA-1 genes by 35.29% and 64.70% respectively while S. aureus isolates was found to load eta gene by 13.51% and ermC gene 18.91% and in the same line ten C. pseudotuberculosis was found to harbor pld gene 40%. Conclusion: It was concluded that Pseudomonas aeruginosa, Staphylococcus aureus as well as Corynebacterium pseudotuberculosis were the most isolated bacterial species in skin infection among sheep and goat in Egypt. Majority of the isolates were MDR and highly resistant to β lactams and quinolones but sensitive to amikacin and imipenem. PCR assays revealed that the isolates carried virulence and antibiotic resistance genes in significant incidence.

First Trial of a Novel Caseous Lymphadenitis Inactivated Vaccine in South Korea: Experimental Evaluation across Various Animal Models.

Caseous lymphadenitis (CLA) is a chronic and subclinical bacterial disease of ruminants caused by Corynebacterium pseudotuberculosis (C. pseudotuberculosis) infection. Until 2014, there were no reports of CLA outbreaks in South Korea; however, the prevalence of CLA cases has steadily increased. In this study, we used recently obtained field isolates to develop the first inactivated CLA vaccine in South Korea and evaluated it in various animal models. The inactivated vaccine was evaluated for virulence and effectiveness. Mice were tested for virulence and immunization challenges, and guinea pigs and Korean Native Black Goats (KNBGs) evaluated various vaccine concentrations to determine the optimal dose and effectiveness. In the case of KNBGs, clinical symptoms were not observed after vaccination. In addition, CLA-specific IgG was detected at a significantly (p < 0.05) high level and was maintained. In histopathological evaluations, inflammation was predominantly observed in the prefemoral lymph nodes in the non-vaccinated+CHAL group. The genetic diversity of C. pseudotuberculosis, which has become widespread in South Korea, is less than 0.5% our vaccine is expected to prevent infection by a wide range of strains effectively. In summary, our CLA vaccine can potentially prevent CLA and foster the growth of South Korea's domestic KNBG industry.

The Etiological and Antimicrobial Susceptibility Profiles of the Bacteria Obtained from Ovine Caseous Lymphadenitis Cases in the Çankırı Region, Türkiye.

Sheep caseous lymphadenitis (CLA) causes significant economic losses in the livestock sector by causing a loss in the quantity and quality of animal products and a loss in the breeding value of animals. Although the primary agent in CLA's etiology is Corynebacterium pseudotuberculosis, some other opportunistic microorganisms also play a role. Therefore, the control and treatment of CLA necessitates the identification of the relevant etiological agents. This study aimed to conduct an in vitro culture and molecular characterization (PCR analysis and 16S rRNA sequencing) of the bacteria involved in sheep CLA cases reported in the Çankırı province of Türkiye and determine the antibiotic susceptibility of the case isolates. In total, 82 (16.4%) of 500 sheep in five farms were diagnosed with CLA. Following the culture of the superficial abscesses samples, C. pseudotuberculosis was identified in 30 (36.59%) as a result of PCR, Pseudomonas spp. in 8 (9.76%), and Enterobacter cancerogenus in 1 (1.22%), as a result of 16S rRNA sequencing. These data revealed extensive heterogeneity among the Pseudomonas isolates, with hints of derivation from a common ancestry for some and phylogenetic similarity to isolates from Germany, Malaysia, and India. In contrast to the high susceptibility to cefoperazone and lincomycin, the high resistances of C. pseudotuberculosis and Pseudomonas spp. isolates to cephalothin, ceftiofur, cloxacillin, amoxicillin, and bacitracin were remarkable. Based on these findings, it was concluded that for an effective treatment and control of ovine CLA cases, there is a need to consider the possible involvement of opportunistic bacteria other than the primary causative agent, C. pseudotuberculosis. It also contributed to increasing the country-specific sequence data and establishing new taxa from a universal perspective.

Corynebacterium pseudotuberculosis: Whole genome sequencing reveals unforeseen and relevant genetic diversity in this pathogen.

Corynebacterium pseudotuberculosis (CPS) is an important bacterial animal pathogen. CPS causes chronic, debilitating and currently incurable infectious diseases affecting a wide range of livestock and wild herbivores including camelids worldwide. Belonging to the Corynebacterium diphtheriae complex, this pathogen can also infect humans. The classical characterization of CPS is typically based on the testing of nitrate reductase activity, separating the two biovars Equi and Ovis. However, more refined resolutions are required to unravel routes of infection. This was realized in our study by generating and analyzing whole genome sequencing (WGS) data. Using newly created core genome multilocus sequence typing (cgMLST) profiles we were the first to discover isolates grouping in a cluster adjacent to clusters formed by CPS biovar Equi isolates. This novel cluster includes CPS isolates from alpacas, llamas, camels and dromedaries, which are characterized by a lack of nitrate reductase activity as encountered in biovar Ovis. This is of special interest for molecular epidemiology. Nevertheless, these isolates bear the genes of the nitrate locus, which are characteristic of biovar Equi isolates. However, sequence analysis of the genes narG and narH of the nitrate locus revealed indels leading to frameshifts and inactivity of the enzymes involved in nitrate reduction. Interestingly, one CPS isolate originating from another lama with an insertion in the MFS transporter (narT) is adjacent to a cluster formed by ovine CPS isolates biovar Equi. Based on this knowledge, the combination of biochemical and PCR based molecular biological nitrate reductase detection can be used for a fast and uncomplicated classification of isolates in routine diagnostics in order to check the origin of camelid CPS isolates. Further analysis revealed that partial sequencing of the ABC transporter substrate binding protein (CP258_RS07935) is a powerful tool to assign the biovars and the novel genomovar.

Iridaea cordata lipid extract associated with the rCP01850 protein of C. pseudotuberculosis elicited a Th1 immune response in immunized sheep

Sheep farming contributes to the socioeconomic development of small and medium-scale livestock farmers. However, several factors can hinder successful animal production, as is the case for infectious diseases, such as the one caused by Corynebacterium pseudotuberculosis, known as caseous lymphadenitis (CLA). CLA has >90% prevalence in Brazilian herds and antibiotic treatment is not effective, consequently causing significant economic losses to farmers. Given the above, effective vaccines need to be developed to prevent this disease. This study aimed to evaluate the adjuvant activity of the lipid extract from the macroalgae Iridaea cordata as a candidate for developing an effective vaccine formulation. For such, four groups of six sheep each were inoculated with sterile 0.9% saline solution (G1), rCP01850 (G2), rCP01850 + I. cordata (G3), and rCP01850 + saponin (G4). Each sheep received two vaccine doses 30 days apart. Total IgG production levels significantly increased in experimental groups G3 and G4 on days 30, 60, and 90. On day 90, G3 showed higher total IgG production (p < 0.05) when compared to G4. When analyzing cytokine production, G3 was the only experimental group with significantly increased IFN-γ, IL-12, TNF-α, and IL-10 mRNA expression levels. Our results show the vaccine formulation containing rCP01850 adjuvanted with the I. cordata lipid extract elicited a Th1 immune response in sheep, indicating I. cordata lipid extract may be a promising adjuvant for developing an effective vaccine against infection caused by C. pseudotuberculosis.

Lactobacillus acidophilus protects against Corynebacterium pseudotuberculosis infection by regulating the autophagy of macrophages and maintaining gut microbiota homeostasis in C57BL/6 mice.

Corynebacterium pseudotuberculosis (C. p) is known to induce a range of chronic diseases in both animals and humans. Currently, clinical treatment for C. p infection mainly relies on antibiotic therapy or surgical intervention. However, excessive use of antibiotics may increase the risk of drug-resistant strains, and the effectiveness of treatment remains unsatisfactory. Furthermore, surgical procedures do not completely eradicate pathogens and can easily cause environmental pollution. Probiotic interventions are receiving increasing attention for improving the body's immune system and maintaining health. In this study, we established a C. p infection model in C57BL/6 mice to explore the impact of Lactobacillus acidophilus during C. p infection. Our results showed that L. acidophilus effectively protected against C. p infection by regulating the autophagy of macrophages and maintaining intestinal microbiota homeostasis. This study may provide a new strategy for the prevention of C. p infection.

Herd-level true seroprevalence of caseous lymphadenitis and paratuberculosis in the goat population of Poland

A large-scale study was carried out in the Polish goat population in 2014–2021 to determine the herd-level true seroprevalence (HTP) of caseous lymphadenitis (CLA) caused by Corynebacterium pseudotuberculosis (Cp) and paratuberculosis (PTB) caused by Mycobacterium avium ssp. paratuberculosis (Map). Two-stage cluster sampling was applied to herds counting at least 20 adult goats (aged >1 year) and in each herd all males and 10–13 females were tested. At least one seropositive goat regardless of its sex was necessary to consider the herd as infected. HTP was estimated using the Bayesian approach with the Gibbs sampler in the EpiTools and reported as the median and 95 % credibility interval (95 % CrI). A total of 1282 adult goats from 86 herds were serologically tested using two commercial ELISAs (Cp-ELISA and Map-ELISA). At least 1 seropositive result of Cp-ELISA and Map-ELISA was obtained in 73/86 herds (84.9 %) and 40/86 herds (46.5 %), respectively. HTP of CLA was estimated at 73.3 % (95 % CrI: 65.0 %, 80.4 %) and HTP of PTB was estimated at 42.9 % (95 % CrI: 25.8 %, 58.0 %). There was a significant positive association between the occurrence of CLA and PTB in the herds (odds ratio 6.0, 95 % confidence interval: 1.2, 28.8; p = 0.010). Probability of the seropositive result for PTB was also significantly higher in Cp-seropositive goats than in Cp-seronegative goats (odds ratio 3.9, 95 % confidence interval: 2.4, 6.3; p < 0.001) which could indicate either a higher risk of co-infection or a higher rate of false positive results for PTB in Cp-positive goats. To investigate this issue, optical densities obtained in Map-ELISA were compared between Cp-positive and Cp-negative goats and results of Map-ELISA were adjusted accordingly. Map-negative sera from Cp-positive goats turned out to have significantly higher optical densities than Map-negative sera from Cp-negative goats (p < 0.001). After the adjustment, the herd-level apparent seroprevalence of PTB was 41.9 % (36/86 herds) so it still fell within the 95 % CrI of HTP of PTB calculated before the adjustment. Concluding, CLA appears to be widespread in the Polish goat population. In many of them it may be subclinical at the moment, however will likely emerge in the future as the disease follows cyclic pattern in Poland. On the other hand, given the total lack of clinical PTB in Polish goats, an explanation for a high HTP of PTB remains unclear and warrants further studies using tests of higher analytical specificity than ELISA.

EPIDEMIOLOGICAL INVESTIGATION OF A FATAL CASE OF DIPHTHERIA IN A RESIDENT OF KYIV OBLAST

Ukraine still has diphtheria. This infection is developed with toxins secreted by pathogens of three Corynebacteria species, such as Corynebacterium diphtheria, Corynebacterium ulcerans, and Corynebacterium pseudotuberculosis. In January 2024, for the first time in recent decade, a fatal case of diphtheria in a resident of the Kyiv oblast was registered in Ukraine. The results of laboratory testing showed the toxigenic microorganism Corynebacterium ulcerans. The diagnosis was established based on the results of the pathological and anatomical autopsy and confirmed by laboratory testing during the examination of sectional samples. When a woman sought medical attention with certain clinical signs, medical care personal did not collect biological samples from the patient for testing on the causative agents of respiratory diseases of viral or bacterial origin, and the primary diagnosis did not contain information about the warnings of diphtheria. This indicates a low alertness of doctors regarding the possibility of the occurrence and spread of diphtheria. The anti-vaccination attitude of the population and migration processes under martial law contribute to a decrease in the level of immunization in the Kyiv oblast and pose a threat to diphtheria outbreaks.

Immune response of BALB/c mice infected with two strains of Corynebacterium pseudotuberculosis

This work evaluated aspects of the immune response of BALB/c mice infected with Corynebacterium pseudotuberculosis (T1 and C57). The fifteen BALB/c mice were euthanized after 70 days of infection and morphologically evaluated, also analyzing the innate and adaptive immune responses. The C57 strain induced more pronounced morphological changes than the T1 strain. There was an increase in CD4+ and CD8+ T cells identified during infection with the C57 strain. Cytokines of the inflammatory profile IL-1α and IL-6 and regulatory IL-13 and IL-10 presented significant differences. Cytokines IL-2, IL-4, INF-γ, IL-22, IL-21, and IL-27 did not differ significantly between groups. The obtained results contribute to a better understanding of the type of response and the immunological mechanisms involved during infection with different strains of C. pseudotuberculosis.

Hematological effects for rabbits immunized by Corynebacterium pseudotuberculosis sonicated antigen

Background: Analyzing Hematological parameters is usually in use to monitor various circumstances such as infection, inflammation and anemia. For that we studied blood parameters which are in touch with immunized laboratory animals (rabbits) after immunizing these animals with Corynebacterium pseudotuberculosis then used an adjuvant of Pseudomonas aeruginosa to stimulate the immune response cells after 2 to 3 weeks of immunization. Different concentrations were used to examine the effect on the animals’ blood parameters changing.Methods: Corynebacterium pseudotuberculosis bacterium was used at current study for evaluating the effect of immunizing laboratory rabbits with two different immune stimulators working together as adjuvant on the blood picture with the aid of 12 breed rabbits from different genders, dividing them at the base of inoculation with pre-killed and sonicated cells of bacteria (antigens) onto 4 categories as following: the group-1 members of rabbits were injected with the antigen, group-2 and group-3 included rabbits injected with the two inoculations at various concentrations; final group, group-4 was the control group.Results: Thus, white blood cells known to be our main line of defenses act firstly in our body towards different infecting microorganisms, their count always was increased through the immunization correlated with other measured parameters. From the results we can see that the lymphocytes percentage had no alteration between the infected and the immunized compared to control group, while the percentage of MID that refers to the monocytes was at the same range in both infected and the immunized control rabbit’s groups. Granulocyte cells percentage, which is including heterophilic, basophilic and eosinophilic cells, was significantly decreased (P&gt;0.05) compared with control at all groups.Conclusion: We conclude that C. pseudotuberculosis might function as a potent immunogen to notice the complete blood picture variations.Keywords: Corynebacterium pseudotuberculosis; Pseudomonas aeruginosa; Sonicated antigen; Blood parameters; Blood picture; Adjuvant

Ovine and Caprine Strains of Corynebacterium pseudotuberculosis on Czech Farms-A Comparative Study.

Caseous lymphadenitis (CLA) is a worldwide disease of small ruminants caused by Corynebacterium pseudotuberculosis, a facultative intracellular pathogen that is able to survive and multiply in certain white blood cells of the host. In this study, 33 strains of C. pseudotuberculosis were isolated from sheep and goats suffering from CLA on nine farms in the Czech Republic. All these strains were tested for their antibiotic susceptibility, ability to form a biofilm and resistance to the effects of commonly used disinfectant agents. To better understand the virulence of C. pseudotuberculosis, the genomes of strains were sequenced and comparative genomic analysis was performed with another 123 genomes of the same species, including ovis and equi biovars, downloaded from the NCBI. The genetic determinants for the virulence factors responsible for adherence and virulence factors specialized for iron uptake and exotoxin phospholipase D were revealed in every analyzed genome. Carbohydrate-Active Enzymes were compared, revealing the presence of genetic determinants encoding exo-α-sialidase (GH33) and the CP40 protein in most of the analyzed genomes. Thirty-three Czech strains of C. pseudotuberculosis were identified as the biovar ovis on the basis of comparative genome analysis. All the compared genomes of the biovar ovis strains were highly similar regardless of their country of origin or host, reflecting their clonal behavior.

Antibacterial Activity of Free and Liposome-Encapsulated Tylosin Against Planktonic and Biofilm Forms of Corynebacterium pseudotuberculosis Isolated from Goats

Antibacterial Activity of Free and Liposome-Encapsulated Tylosin Against Planktonic and Biofilm Forms of Corynebacterium pseudotuberculosis Isolated from Goats

Susceptibility of Corynebacterium pseudotuberculosis to selected antimicrobial agents

Abstract Caseous lymphadenitis is a chronic disease that affects small ruminant farms worldwide and causes economic losses to breeders. The disease is caused by the bacterium Corynebacterium pseudotuberculosis, which penetrates the lymph nodes of the host and induces the formation of abscesses. This bacterium is able to form a biofilm to protect itself against adverse environmental conditions, disinfectants and antibiotics. In this study, 33 field isolates of the bacterium Corynebacterium pseudotuberculosis obtained from nine sheep and goat farms in the Czech Republic were examined. The susceptibility of these isolates to eight antibiotics, which were chosen according to the European Committee on Antimicrobial Susceptibility. Testing (EUCAST) breakpoints for Corynebacterium spp. and according to the spectrum of antibiotics used in individual farms, was investigated. The analyses were also supplemented with tests of the biofilm formation ability of individual isolates and with tests of the sensitivity of these biofilms to a disinfectant based on active chlorine.

Caseous Lymphangitis in a Goat Farm

Caseous lymphadenitis (CL) is a sporadic bacterial disease of chronic suppurative lymphadenitis in goats. The prevalence of CL is considered high in many countries, but detailed research on prevalence rates, farm practices, and abattoir findings is limited in India. This paper reports the presence of this disease on an endemic form in a goat farm. A two-year-old mixed breed doe was presented with the history of swelling in mandibular region and inappetence for the past one week. Greenish pus was aspirated from it and Giemsa stain confirms the presence of coccobacillus bacteria. Culture and isolation identified it as Corynebacterium pseudotuberculosis on 10% sheep blood agar. The abscess drained off, flushed with 5 % iodine solution and treated with injection lincomycin @ 10 mg/kg until recovery. The same history was repeated by the owner after a month and visit to the farm exposed three more animals were also affected. All of them confirmed CL based on bacterial culture and isolation. Based on this it was confirmed that the disease was endemic in that farm. Rearing goats as semi-intensive flocks, sharing of grazing fields together with other animals, commingling of animals after grazing particularly in the night time, rupture of abscess in the shelter itself, improper knowledge about disease and poor husbandry practices favours the endemicity of this disease in goats. This paper reports the endemicity of the caseous lymphadentitis in a goat flock.

Activity of biogenic silver nanoparticles in planktonic and biofilm-associated Corynebacterium pseudotuberculosis.

Corynebacterium pseudotuberculosis is a gram-positive bacterium and is the etiologic agent of caseous lymphadenitis (CL) in small ruminants. This disease is characterized by the development of encapsulated granulomas in visceral and superficial lymph nodes, and its clinical treatment is refractory to antibiotic therapy. An important virulence factor of the Corynebacterium genus is the ability to produce biofilm; however, little is known about the characteristics of the biofilm produced by C. pseudotuberculosis and its resistance to antimicrobials. Silver nanoparticles (AgNPs) are considered as promising antimicrobial agents, and are known to have several advantages, such as a broad-spectrum activity, low resistance induction potential, and antibiofilm activity. Therefore, we evaluate herein the activity of AgNPs in C. pseudotuberculosis, through the determination of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity, and visualization of AgNP-treated and AgNP-untreated biofilm through scanning electron microscopy. The AgNPs were able to completely inhibit bacterial growth and inactivate C. pseudotuberculosis at concentrations ranging from 0.08 to 0.312 mg/mL. The AgNPs reduced the formation of biofilm in reference strains and clinical isolates of C. pseudotuberculosis, with interference values greater than 80% at a concentration of 4 mg/mL, controlling the change between the planktonic and biofilm-associated forms, and preventing fixation and colonization. Scanning electron microscopy images showed a significant disruptive activity of AgNP on the consolidated biofilms. The results of this study demonstrate the potential of AgNPs as an effective therapeutic agent against CL.