Association of Streptococcus pluranimalium with valvular endocarditis and septicaemia in adult broiler parents

Case reports involving coinfection with Avibacterium paragallinarum and Ornithobacterium rhinotracheale in broiler chickens and Avibacterium endocarditis in broiler breeding hens in Poland

ABSTRACTThe study describes three clinical cases of infection with Avibacterium spp.. In case no. 1, respiratory clinical signs and high mortality (0.7-4.2% daily; total 21.2%) in Ross 308 broiler chickens were shown to be caused by coinfection with sequence type 9 of O. rhinotracheale presumptive serotype A and A. paragallinarum presumptive serotype B. The identical (pulsed-field gel electrophoresis) restriction pattern (pulsotype) of seven A. paragallinarum isolates indicated that infectious coryza in broilers was caused by the same clone. In cases 2 and 3, sudden increased deaths in Ross 308 broiler breeders (especially males) with lesions in the endocardium (valvular or mural endocarditis) were shown to be caused by A. endocarditis. Among nine antibiotics tested, florfenicol was the only antibiotic to which all A. paragallinarum and O. rhinotracheale isolates were susceptible. Out of the eight antibiotics tested, 11 A. endocarditis isolates from both clinical cases of infective endocarditis were susceptible to penicillin, amoxicillin, doxycycline and florfenicol. The A. endocarditis isolates tested in both clinical cases had different PFGE patterns (pulsotypes), but identical within a case. The causes of infectious coryza and infective endocarditis in the cases presented have not been determined. In the prevention of infectious diseases in large-scale livestock farming, it is very important to follow the rules of biosecurity.

The pseudokinase MLKL contributes to host defense against Streptococcus pluranimalium infection by mediating NLRP3 inflammasome activation and extracellular trap formation

Host innate immunity plays a pivotal role in the early detection and neutralization of invading pathogens. Here, we show that pseudokinase mixed lineage kinase-like protein (MLKL) is required for host defence against Streptococcus pluranimalium infection by enhancing NLRP3 inflammasome activation and extracellular trap formation. Notably, Mlkl deficiency leads to increased mortality, increased bacterial colonization, severe destruction of organ architecture, and elevated inflammatory cell infiltration in murine models of S. pluranimalium pulmonary and systemic infection. In vivo and in vitro data provided evidence that potassium efflux-dependent NLRP3 inflammasome signalling downstream of active MLKL confers host protection against S. pluranimalium infection and initiates bacterial killing and clearance. Moreover, Mlkl deficiency results in defects in extracellular trap-mediated bactericidal activity. In summary, this study revealed that MLKL mediates the host defence response to S. pluranimalium, and suggests that MLKL is a potential drug target for preventing and controlling pathogen infection.

Disseminated Streptococcus gallinaceus infection. A new breed of zoonotic Streptococcus

Streptococcus gallinaceus is a new species of Streptococcus that was first isolated in 2004 in chickens. Infections in humans are associated with chicken exposure. There are very few case reports of human infections with this organism and none with disseminated infection. We report a case of Streptococcus gallinaceus bacteremia complicated by aortic valve endocarditis and lumbar osteomyelitis and paraspinal abscess in a patient with chicken exposure. The patient presented with progressive lower back pain and malaise. Blood culture was positive for Streptococcus gallinaceus. Magnetic resonance imaging (MRI) of the spine showed L2-L3 osteomyelitis with a compression fracture and paraspinal abscess. Transthoracic echocardiography revealed severe aortic insufficiency, 1-cm aortic valve echo density suspected to be a vegetation, and perforation of the right coronary cusp. He subsequently underwent anaortic valve repair. Pathology confirmed acute endocarditis with associated vegetations and granulation tissues. He was successfully treated with a six-week course of ceftriaxone.

Effects of a Specific Pre- and Probiotic Combination and Parent Stock Vaccination on Performance and Bacterial Communities in Broilers Challenged with a Multidrug-Resistant Escherichia coli

Antibiotic resistance poses a risk for human and animal health, leading to a growing demand for effective alternatives. Combining nutritional tools and parent stock vaccination could be an approach to achieve sufficient protection against bacterial infections in poultry. In an Escherichia coli O1/O18 challenge trial, we investigated the protective effects of feeding diets containing Enterococcus faecium DSM 7134 and fructooligosaccharides (FOS) combined with specific parent stock vaccination in 225 ROSS 308 broilers. Data on performance parameters, intestinal microbial composition and metabolites, and antibiotic resistance genes (sul1-3, dhfr1a, SHV-12) were obtained. E. faecium and FOS combined with parent stock vaccination led to the highest body weights, which were significantly higher than those of controls throughout the experiment and decreased the relative abundance of Proteobacteria in the crop digesta compared to that in the positive control. However, cumulative feed conversation remained unaffected by the strategies. Birds receiving the pre-/probiotic combination showed lower cecal pH levels and higher crop L-lactate concentrations than the controls, whereas copy numbers of dhfr1a (trimethoprim resistance) and SHV-12 (extended-spectrum beta-lactamase) genes were only decreased in broilers from vaccinated hens compared to those in the challenged control. In conclusion, prophylactic administration of E. faecium and FOS in combination with parent stock vaccination can have complementary effects by improving broiler weight gain and stimulating intestinal bacterial metabolism, which may be beneficial for maintaining gut health in terms of Escherichia coli infection.

Identification and Characterization of a Two-Peptide Class IIb Bacteriocin in Streptococcus pluranimalium Isolated from the Nasal Cavity of a Healthy Pig

In addition to be an important zoonotic agent, Streptococcus suis serotype 2 causes severe infections in pigs. In this study, we characterized a new bacteriocin produced by Streptococcus pluranimalium 2N12 isolated from a pig nasal sample. The bacteriocin, termed pluranimalicin 2N12, was a two-peptide class IIb bacteriocin active against S. suis. The gene cluster responsible for the biosynthesis of pluranimalicin 2N12 by S. pluranimalium contained seven open reading frames, including putative genes for peptides (pluα, pluβ), export (pluA, pluB), and regulation (pluC, pluD, pluE). The deduced amino acid sequences of the peptides Pluα (33 amino acids) and Pluβ (29 amino acids) showed 73% and 69% identity in amino acid residues, respectively, with the peptides SthA and SthB of the streptocin produced by Streptococcus gordonii. The antibacterial activity of pluranimalicin 2N12 against S. suis was dependent on the presence of the two peptides Pluα and Pluβ that exhibited a membrane permeabilization effect. No activity was found against the other swine pathogens tested. Depending on the concentrations used, Pluα and Pluβ displayed no or low toxicity towards swine tracheal epithelial cells. The pluranimalicin peptides Pluα and Pluβ, either individually or in combination, exhibited anti-inflammatory activity since they attenuated IL-6 and TNF-α production by macrophages challenged with lipopolysaccharide. Given its dual action (antibacterial and anti-inflammatory), pluranimalicin 2N12 holds promise as a potential therapeutic agent for controlling S. suis infections.

Streptococcus pluranimalium meningoencephalitis in a horse

A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. Streptococcus pluranimalium was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. S. pluranimalium should be considered as a cause of meningoencephalitis in a horse.

Vegetative Endocarditis due to Staphylococcus aureus in an Umbrella Cockatoo (Cacatua alba)

A 15-year-old, female cockatoo (Cacatua alba) was presented with a history of intermittent cloacal prolapse of 1-year duration. After each prolapse, the owner would digitally reduce the distended cloacal tissue within approximately 12-24 hours, for short-term resolution. The cockatoo was examined 3 times over a 7-month period and received supportive care with leuprolide acetate, behavioral modification, and diet change. After the third examination, the owner decided to proceed with a surgical cloacopexy. Five days after the last examination and before the procedure was scheduled, the cockatoo was reexamined for acute onset of weakness, anorexia, lethargy, and right-leg paresis. Despite supportive treatment, the cockatoo's clinical condition declined, and it went into respiratory arrest. Resuscitative efforts, including manual ventilation and cardiovascular support, were unsuccessful, and the bird died. Results of postmortem examination revealed vegetative endocarditis with intralesional bacteria cultured as Staphylococcus aureus, right-hindlimb myonecrosis, hepatitis, and nephritis. We suspect that the source of the hematogenous S aureus infection in this cockatoo was translocation from the owner's skin from the repeated manual manipulation and replacement of the prolapsed cloacal tissue.

The first report of Streptococcus pluranimalium infection from Iran: A case report and literature review

The Streptococcus pluranimalium was isolated from both of animals and human infection. There is limited information about pathogenicity of S pluranimalium. As fastidious bacteria, S pluranimalium is not isolated in the routinely culture media and easily misidentified with other streptococci species with conventional microbiology test. According to review of the literatures, the cephalosporins, aminoglycosides, vancomycin, and linezolid are the first choice agents for treatment of infection caused by S pluranimalium.

Streptococcus pluranimalium infective endocarditis and brain abscess

Infective endocarditis is an infection of the endocardium of the heart typically seen in individuals with underlying risk factors. We report a rare case of Streptococcus pluranimalium bacteremia causing infective endocarditis and brain abscess. Only 3 cases were reported in the literature on infective endocarditis in patients secondary to S. pluranimalium.

The application of the loop-mediated isothermal amplification (LAMP) method for diagnosing Enterococcus hirae-associated endocarditis outbreaks in chickens

BACKGROUND

Enterococcus hirae is considered a part of the normal intestinal biota of several domestic animals, including poultry. However, this species is also associated with infective endocarditis in chickens, a disease that leads to unexpected deaths and serious economical losses. Enterococcus hirae is identified predominantly with the use of conventional bacteriological methods, biochemical tests and PCR. Rapid, sensitive and specific methods for detecting E. hirae in clinical samples are required in poultry production. The aim of this study was to use the Loop-Mediated Isothermal Amplification (LAMP) for the identification and quantification of E. hirae in heart samples from broiler chickens.

RESULTS

The specificity of the LAMP method was confirmed for 7 enterococcal strains and 3 non-enterococcal strains. E. hirae was detected in all of the 22 analyzed clinical bacterial isolates and in all of the 9 heart samples. Three sets of primers supported the detection of E. hirae with high sensitivity and specificity within one hour. The highest detection rate of a LAMP product was approximately 7 min for an E. hirae strain and 12 min for a positive heart sample. The detection limit for the E. hirae ATCC 10541 standard was 1.3 × 10² CFU (43.4 fg) or 13.8 copies of the E. hirae genome equivalent per reaction. The reaction was 10-fold more sensitive than conventional species-specific PCR. The LAMP assay supported the determination of the E. hirae load in chicken hearts with endocarditis in field cases. The average number of E. hirae cells in hearts was 5.19 × 10⁷ CFU/g of tissue, and the average number of E. hirae genome equivalents in hearts was 5.51× 10⁶ copies/g of tissue. Bacterial counts were significantly higher in the LAMP assay than in the standard plate count.

CONCLUSIONS

The LAMP assay is a useful diagnostic tool and an effective alternative to conventional methods for the detection of this enterococcal species. The sodA-based LAMP assay supported direct identification of E. hirae from pure cultures and heart samples without previous bacterial cultivation. This is the first study to apply the LAMP method for the purpose of diagnosing E. hirae-associated endocarditis in poultry.

Characterization of Streptococcus pluranimalium from a cattle with mastitis by whole genome sequencing and functional validation

Background

Streptococcus pluranimalium is a new member of the Streptococcus genus isolated from multiple different animal hosts. It has been identified as a pathogen associated with subclinical mastitis, valvular endocarditis and septicaemia in animals. Moreover, this bacterium has emerged as a new pathogen for human infective endocarditis and brain abscess. However, the patho-biological properties of S. pluranimalium remain virtually unknown. The aim of this study was to determine the complete genome sequence of S. pluranimalium strain TH11417 isolated from a cattle with mastitis, and to characterize its antimicrobial resistance, virulence, and carbon catabolism.

Results

The genome of S. pluranimalium TH11417, determined by single-molecule real-time (SMRT) sequencing, consists of 2,065,522 base pair (bp) with a G + C content of 38.65%, 2,007 predicted coding sequence (CDS), 58 transfer RNA (tRNA) genes and five ribosome RNA (rRNA) operons. It contains a novel ISSpl1 element (a memeber of the IS3 family) and a Ф11417.1 prophage that carries the mef(A), msr(D) and lnu(C) genes. Consistently, our antimicrobial susceptibility test confirmed that S. pluranimalium TH11417 was resistant to erythromycin and lincomycin. However, this strain did not show virulence in murine pneumonia (intranasal inoculation, 10⁷ colony forming unit – CFU) and sepsis (intraperitoneal inoculation, 10⁷ CFU) models. Additionally, this strain is able to grow with glucose, lactose or galactose as the sole carbon source, and possesses a lactose-specific phosphoenolpyruvate-dependent phosphotransferase system (PTS).

Conclusions

We reported the first whole genome sequence of S. pluranimalium isolated from a cattle with mastitis. It harbors a prophage carrying the mef(A), msr(D) and lnu(C) genes, and is avirulent in the murine infection model.

Streptococcus pluranimalium: Emerging Animal Streptococcal Species as Causative Agent of Human Brain Abscess

BACKGROUND

Streptococcus pluranimalium is a new and emerging animal streptococcal species associated with primary infection in bovine and avian species. Data in the literature regarding its pathogenic significance in human beings are limited. We hereby report a case of brain abscess caused by S. pluranimalium in a healthy adult male. S. pluranimalium, a causative agent of brain abscess, was unanticipated, and to the best of our knowledge, this is one of the rare cases reported in the medical literature.

CASE DESCRIPTION

A 44-year-old male presented with headache and occasional episodes of vomiting for 2 weeks, weakness of the left upper and lower limbs for 1 week, and 1 episode of generalized tonic clonic seizure 2 days back. He was afebrile and had no history of loss of consciousness or head trauma. His physical and neurologic examination was unremarkable. Magnetic resonance imaging of the brain revealed a focal ring enhancing lesion in right posterior parietal lobe, suggestive of infective etiology. The patient underwent right parietooccipital craniotomy and excision of cerebral abscess, from which S. pluranimalium was isolated. The patient responded to treatment with intravenous ceftriaxone, vancomycin, and metronidazole without any residual neurologic sequelae.

CONCLUSION

Clinical data regarding epidemiology, pathogenic mechanisms, and zoonotic potential of S. pluranimalium in human beings are lacking. The number of cases of human infections with S. pluranimalium are steadily increasing. Hence further detailed study of the pathogenesis of S. pluranimalium in human beings is warranted, which may help to develop new strategies to prevent and treat infection with this bacterium.

ISOLATION OF STREPTOCOCCI FROM A FATAL CASE OF MYOCARDITIS IN A CAPTIVE BROWN BEAR (URSUS ARCTOS)

A 10-yr-old, male brown bear ( Ursus arctos ) from Bursa Zoo in Turkey died without any apparent signs. Severe purulent pericarditis and myocarditis with mild ascites, lung edema, and moderate liver congestion were observed during necropsy. Microscopically, there were severe neutrophilic infiltrations in the myocardium and thoracic lymph nodes. A member of the Streptococcus bovis - Streptococcus equinus complex (SBSEC) was isolated and identified phenotypically.

Staphylococcus simulans associated with endocarditis in broiler chickens

This report suggests a strong association between coagulase-negative Staphylococcus simulans and endocarditis in broiler chickens of a single flock. Clinical signs included increased mortality and lameness, and some dead chickens were found on their backs. Lesions included cauliflower-like, fibrinous vegetative lesions on the left atrioventricular valve; cream-coloured, necrotic foci of varying size in the liver; and necrosis of the femoral head. Histopathological examination of the heart revealed multifocal conglomerates of bacterial colonies attached to the valvular endocardium, threads of fibrin, and inflammatory cells with the presence of heterophils. S. simulans strains were first identified by API ID32, and then confirmed with Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and by partial sequencing of the rpoB and dnaJ genes. These bacteria were resistant to methicillin but sensitive to vancomycin and characterized by slime production and protease activity.

Short communication: Role of Streptococcus pluranimalium in Mediterranean buffaloes (Bubalus bubalis) with different udder health statuses

The aims of the current study were to describe presence and clinical role over time of Streptococcus pluranimalium isolated in milk samples of Mediterranean buffalo (MB). Two hundred composite milk samples originating from 40 primiparous MB were collected at 10, 30, 60, 90, and 150d in milk (DIM) and from 20 pluriparous MB at 77 to 120 DIM. Milk samples were used for analysis of somatic cell counts, bacteriological cultures, and identification (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). Nine of 200 (4.5%) samples of primiparous MB and 3 of 20 (15%) samples of pluriparous MB were positive for Strep. pluranimalium. The prevalence of the bacterium in primipari was 0% (0/40) at 10, 30, and 150 DIM, whereas it was 5 (2/40) and 17.5% (7/40) at 60 and 90 DIM, respectively. Eight primipari were positive only once, whereas 1 was positive at 2 different samplings. Mono-infection was not detected in any of the age categories or udder health status. Infections were transient in primipari. Clinical mastitis was observed in primipari once at 90 DIM, subclinical mastitis detected twice in the same animals at 60 and 90 DIM, and intramammary infections were diagnosed 1 and 5 times at 60 and 90 DIM in primipari, respectively, whereas 3 infections were diagnosed in pluripari. The clinical reflections demonstrate for the first time the presence of Strep. pluranimalium in MB and its association with different udder health status. Nevertheless, it cannot be excluded that the bacterium may simply follow a pattern of commensal or opportunistic behavior, taking advantage of a preexisting bacterial udder infection.

Streptococcus gallolyticus subsp. gallolyticus from human and animal origins: genetic diversity, antimicrobial susceptibility, and characterization of a vancomycin-resistant calf isolate carrying a vanA-Tn1546-like element

The aim of this work was to characterize the antibiotic susceptibility and genetic diversity of 41 Streptococcus gallolyticus subsp. gallolyticus isolates: 18 isolates obtained from animals and 23 human clinical isolates. Antibiotic susceptibility was determined by the semiautomatic Wider system and genetic diversity by pulsed-field gel electrophoresis (PFGE) with SmaI. Animal isolates grouped separately in the PFGE analysis, but no statistical differences in antimicrobial resistance were found between the two groups. The LMG 17956 sequence type 28 (ST28) strain recovered from the feces of a calf exhibited high levels of resistance to vancomycin and teicoplanin (MIC, ≥256 mg/liter). Its glycopeptide resistance mechanism was characterized by Southern blot hybridization and a primer-walking strategy, and finally its genome, determined by whole-genome sequencing, was compared with four closely related S. gallolyticus subsp. gallolyticus genomes. Hybridization experiments demonstrated that a Tn1546-like element was integrated into the bacterial chromosome. In agreement with this finding, whole-genome sequencing confirmed a partial deletion of the vanY-vanZ region and partial duplication of the vanH gene. The comparative genomic analyses revealed that the LMG 17956 ST28 strain had acquired an unusually high number of transposable elements and had experienced extensive chromosomal rearrangements, as well as gene gain and loss events. In conclusion, S. gallolyticus subsp. gallolyticus isolates from animals seem to belong to lineages separate from those infecting humans. In addition, we report a glycopeptide-resistant isolate from a calf carrying a Tn1546-like element integrated into its chromosome.

Streptococcus pluranimalium: A novel human pathogen?

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Subdural empyema is difficult to differentiate from meningitis on clinical examination alone.

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CT or MRI imaging must be performed for definitive diagnosis.

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Prompt diagnosis, IV antibiotics and neurosurgical evacuation improve morbidity and mortality.

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Use of prophylactic anticonvulsants and wide-exposure craniotomy are recommended.

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Streptococcus pluranimalium needs to be further studied to assess for zoonotic potential.

INTRODUCTION

We present the first case of a subdural empyema caused by Streptococcus pluranimalium, in a healthy adolescent male as a possible complication of subclinical frontal sinusitis. Clinical features, diagnostic approach and management of subdural empyema are discussed.

PRESENTATION OF CASE

A 17-year-old male with a 2 day history of headache and nausea was referred to our Emergency Department (ED) as a case of possible meningitis. He was afebrile, lethargic and drowsy with significant neck stiffness on examination. Computerized tomography (CT) revealed a large frontotemporoparietal subdural fluid collection with significant midline shift. Subsequent contrast-enhanced CT established the presence of intracranial empyema; the patient underwent immediate burr-hole evacuation of the pus and received 7 weeks of intravenous antibiotics, recovering with no residual neurological deficit.

DISCUSSION

The diagnosis of subdural empyema as a complication of asymptomatic sinusitis in an immunocompetent patient with no history of fever or upper respiratory symptoms was unanticipated. Furthermore, the organism Streptococcus pluranimalium that was cultured from the pus has only been documented twice previously in medical literature to cause infection in humans, as it is primarily a pathogen responsible for infection in bovine and avian species.

CONCLUSION

Subdural empyema represents a neurosurgical emergency and if left untreated is invariably fatal. Rapid diagnosis, surgical intervention and intensive antibiotic therapy improve both morbidity and mortality.

Idiopathic necrotising enteritis cases continue

Cases of idiopathic necrotising enteritis in calves continue Polioencephalitis of unknown cause in lambs Rare types of deformities seen in piglets Colibacillosis in postweaned pigs Rotavirus in gamebirds These are among matters discussed in the Animal Health and Veterinary Laboratories Agency's (AHVLA's) disease surveillance report for June 2014.

Ulcerative dermatitis and valvular endocarditis associated with Staphylococcus aureus in a hyacinth macaw (Anadorhynchus hyacinthinus)

An 18-yr-old male hyacinth macaw (Anadorhynchus hyacinthinus) was found dead in his aviary with no preexisting signs. The bird had a chronic history of feather damaging behavior, with severe ulcerative dermatitis. Pathologic findings revealed a vegetative valvular endocarditis, myocarditis, septicemia, chronic severe glomerulonephritis, and thyroid dysplasia. Staphylococcus aureus was isolated from the valve, the liver, and the skin. Repeated trauma and low-rate bacteriemia may have contributed to the development of endocarditis. Translocation of S. aureus skin infection in the bloodstream may lead to subacute endocarditis in humans and such mechanism is suspected in this case. This case suggests that endocarditis associated with S. aureus septicemia is a potential complication of feather damaging behavior. This case also reports a systemic complication of ulcerative dermatitis secondary to feather damaging behavior. Endocarditis has been poorly reported in psittacine species, and such medical complication of feather damaging behavior has never been reported to our knowledge. Furthermore, S. aureus is a bacteria of public health concern and should be integrated into the differential when pet parrots with dermatitis are in proximity to owners.

Pathology and localization of Avibacterium endocarditidis in experimentally infected broiler breeders

The aim of this study was to investigate the pathogenic potential of Avibacterium endocarditidis. Forty broiler breeders were inoculated with one of three doses of the organism and killed at different time points. Bacteriology, pathology and fluorescence in-situ hybridization (FISH) were performed to evaluate bacterial growth and the development of lesions. Abundant growth in pure culture of A. endocarditidis was always obtained from valvular lesions, while only poor growth or no growth was obtained from liver and spleen lesions, confirming previous observations from naturally occurring cases. Gross lesions and histopathological findings confirmed previous observations. Valvular lesions were acute, ranging from slight thickening of the valves to severe inflammation. In most cases, bacteria colonized the valves. Lesions observed in the spleen included different degrees of necrosis and liver lesions ranged from very small infarcts to large areas of coagulative necrosis. Arthritis occurred in 19 birds, 15 of which tested positive for A. endocarditidis. Most birds developed bacteraemia, but the inability to isolate bacteria from the liver and spleen and the lack of bacteria demonstrated by FISH and histopathology, suggested lack of fulminant septicaemia. A significant correlation between the size of dose inoculated and development of valvular endocarditis was not observed; however, regressive changes in the ovary, liver necrosis and hepato-, spleno- and renomegaly were significantly dose dependent. A. endocarditidis represents a potential pathogen for chickens, the reservoir of which remains to be determined.

Co-infection of Ornithobacterium rhinotracheale with Streptococcus zooepidemicus in chickens

An outbreak of bronchial embolization with 50%-70% morbidity and 30% mortality occurred in broilers in northeast China. This highly contagious disease is characterized by the sudden onset of clinical symptoms, including dyspnea, hemorrhagic tracheal discharge, and bronchial obstruction. Subsequently, six strains of Ornithobacterium rhinotracheale (ORT) and three strains of Streptococcus zooepidemicus were isolated from the various organs and identified using biochemical tests and PCR methods. The pathogenesis of embolization in chickens is poorly understood. The current experimental study confirmed that ORT infection alone could induce a significantly fatal hemorrhagic pneumonia and high mortality in comparison with S. zooepidemicus infection. Moreover, co-infection of ORT with S. zooepidemicus could induce even higher mortality, with severe bronchial obstruction, than that observed in chickens infected with S. zooepidemicus or ORT alone. Therefore, the combination of ORT and S. zooepidemicus may be associated with the outbreak of chicken bronchial embolization. Further investigation of the pathogenesis of ORT and Streptococcus is urgently needed.

A major outbreak of Streptococcus equi subsp. zooepidemicus infections in free-range chickens is linked to horses

Infections of poultry due to Streptococcus equi subsp. zooepidemicus have been rare during the past decades and dissimilarities have been reported as to symptoms and lesions; likewise, the source of serious outbreaks has remained speculative. An outbreak affecting 11,000 free-range chickens at the age of 47 wk is reported. The outbreak manifested itself as acute at the onset and was followed by a chronic stage, resulting in some 80% mortality within 21 wk. Small-colony variants (SCVs) of S. equi subsp. zooepidemicus associated with the chronic phase are reported for the first time, and it is discussed whether SCVs might explain the change in lesions observed. Comparison of partial sequences of rpoB, multilocus sequence typing, and pulsed-field gel electrophoresis of isolates from chickens and horses kept at the farm showed the isolates to be identical and horses a likely source of infection. The present findings underline the importance of protecting free-range chickens from contact with other animals and birds known to host pathogens of importance to poultry.

Antibiotic resistance genes and virulence factors in Enterococcus faecium and Enterococcus faecalis from diseased farm animals: pigs, cattle and poultry

Eighty enterococcal isolates (E. faecium, n=38,E. faecalis, n=42) from diseased farm animals (swine, cattle, poultry) in Lithuania have been studied for the prevalence of antibiotic resistance and for resistance and virulence genetic determinants. 86% ofE. faeciumand 71% ofE. faecalisisolates were multidrug resistant (resistant to three or more unrelated antibiotics). Resistance to aminoglycosides, tetracycline and erythromycin was found most frequently in both species (61%, 69%) and was linked toaph(3’)-IIIa,aac(6’)-Ie-aph(2”)-Ia,ant(6)-Ia (aminoglycoside resistance),tetM,tetL(tetracycline resistance),ermA,ermB(erythromycin resistance) gene combinations, which were supplemented with chloramphenicol resistance genescatA7,catA8(E. faecalis) andcatA9(E. faecium). AllE. faecalisisolates harboured genes coding for virulence factorsagg,esp,fsr gelEalone or in combinations with the high prevalence ofespgene in isolates from cattle (63%) and pigs (79%). The origin- dependent incidence ofagggene variantsprgBandasp1was observed. The results indicate the existence of a large pool of potentially virulent and multidrug resistantE. faecalisin diseased farm animals posing risk to humans.

Observations on the incidence and aetiology of valvular endocarditis in broiler breeders and detection of a newly described taxon of Pasteurellaceae, Avibacterium endocarditidis

A total of 122 dead broiler breeders randomly selected from a flock showing normal production parameters and covering the age from 44 to 61 weeks were subjected to a comprehensive routine post-mortem examination including examination for lesions of endocarditis. Forty-two hens (34%) showed valvular endocarditis caused by Avibacterium endocarditidis (43%), Enterococcus faecalis (31%), Staphylococcus aureus (5%) and Streptococcus pluranimalium (5%), while growth was not obtained from 17% with the methods used for isolation. Gross lesions associated with the different bacterial pathogens did not allow separation according to pathogens involved. Port of entry and pathogenesis associated with the high prevalence of valvular endocarditis remained speculative. The present findings demonstrated the newly described species of Pasteurellaceae, Avibacterium endocarditidis associated with endocarditis in chickens and confirm previous observations on the prevalence of endocarditis in chickens, partly explaining the slightly increased mortality normally observed in broiler breeders during the last weeks of production.