The contribution of the immune response to enhanced colibacillosis upon preceding viral respiratory infection in broiler chicken in a dual infection model.

Colibacillosis in chickens caused by avian pathogenic Escherichia coli (APEC) is known to be aggravated by preceding infections with infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and avian metapneumovirus (aMPV). The mechanism behind these virus-induced predispositions for secondary bacterial infections is poorly understood. Here we set out to investigate the immunopathogenesis of enhanced respiratory colibacillosis after preceding infections with these three viruses. Broilers were inoculated intratracheally with APEC six days after oculonasal and intratracheal inoculation with IBV, NDV, aMPV or buffered saline. After euthanasia at 1 and 8 days post infection (dpi) with APEC, birds were macroscopically examined and tissue samples were taken from the trachea, lungs and air sacs. In none of the groups differences in body weight were observed during the course of infection. Macroscopic lesion scoring revealed most severe tissue changes after NDV-APEC and IBV-APEC infection. Histologically, persistent tracheitis was detected in all virus-APEC groups, but not after APEC-only infection. In the lungs, mostly APEC-associated transient pneumonia was observed. Severe and persistent airsacculitis was present after NDV-APEC and IBV-APEC infection. Bacterial antigen was detected by immunohistochemistry only at 1 dpi APEC, predominantly in NDV-APEC- and IBV-APEC-infected lungs. Higher numbers of CD4+ and CD8+ lymphocytes persisted over time in NDV-APEC- and IBV-APEC-infected tracheas, as did CD4+ lymphocytes in NBV-APEC- and IBV-APEC-infected air sacs. KUL01+ cells, which include monocytes and macrophages, and TCRγδ+ lymphocytes were observed mostly in lung tissue in all infected groups with transient higher numbers of KUL01+ cells over time and higher numbers of TCRγδ+ lymphocytes mainly at 8 dpi. qPCR analysis revealed mostly trends of transient higher levels of IL-6 and IFNγ mRNA in lung tissue after IBV-APEC and also NDV-APEC infection and persistent higher levels of IL-6 mRNA after aMPV-APEC infection. In spleens, transient higher levels of IL-17 mRNA and more persistent higher levels of IL-6 mRNA were observed after all co-infections. No changes in IL-10 mRNA expression were seen. These results demonstrate a major impact of dual infections with respiratory viruses and APEC, compared to a single infection with APEC, on the chicken respiratory tract and suggest that immunopathogenesis contributes to lesion persistence.

Mycobacterial Airsacculitis Caused by Mycobacterium fortuitum in a Southern Rockhopper Penguin (Eudyptes chrysocome).

A 21-year-old male southern rockhopper penguin (Eudyptes chrysocome) was presented with a chronic history of intermittently decreased appetite, lethargy, and regurgitation. On the external physical examination, the bird was determined to be in fair-to-thin body condition with the complete blood count and plasma chemistry panel being largely unremarkable. Full-body radiographic images were considered normal, and gastroscopy showed only mild gastritis and duodenitis. The penguin was euthanatized shortly thereafter due to acute onset of respiratory distress. During the gross necropsy examination, the bird had severe airsacculitis with thick, yellow-to-tan, moist granular plaques adhering to the surface of many air sacs, as well as regional contiguous pneumonia. Intralesional acid-fast bacilli were observed in histologic sections of air sac tissue, and polymerase chain reaction of the affected air sacs was positive for Mycobacterium fortuitum. This clinical case study describes mycobacteriosis in a sub-Antarctic penguin and to the best of the authors' knowledge, the first reported isolation of M fortuitum from a penguin.

Duration of protective immunity induced by Mycoplasma gallisepticum strain ts-304 vaccine in chickens.

Mycoplasma gallisepticum (MG) is an important pathogen of poultry worldwide, causing chronic respiratory disease in chickens and turkeys. MG ts-304 is a GapA positive clone recovered from Vaxsafe MG (strain ts-11) that has been shown to be safe in chickens when delivered by the eye drop route to 3-week-old specific-pathogen-free chickens and to confer protection against challenge at 4 weeks after vaccination, as measured by tracheal mucosal thickness and air sac lesion scores. In this study, specific pathogen-free chickens (SPF) were vaccinated with a single dose of the MG ts-304 vaccine (106.0 colour changing units) at 3 weeks of age and experimentally challenged by aerosol with the virulent M. gallisepticum strain Ap3AS at 40, 48 and 57 weeks after vaccination. There were no significant differences in tracheal mucosal thickness 2 weeks after challenge between chickens challenged at the three time points, or between the vaccinated birds after challenge and unvaccinated/unchallenged control birds. Thus there was clear evidence that the immunity conferred by vaccination with the MG ts-304 vaccine resulted in significant protection against tracheitis in chickens that extended to, but was highly likely to exceed, 57 weeks after vaccination and that similar long term protective immunity could be expected to be conferred by a vaccine dose lower than that used in this study.

Classificação dos graus de lesões de aerossaculite em perus associadas com enterobactérias / [Classification of the levels of the airsacculitis injuries in turkeys associated with Enterobacteriaceae]

Foram padronizados os graus de lesões dos sacos aéreos em perus com aerossaculite, associadas com a presença de isolados de enterobactérias nesses órgãos. Um total de 110 amostras de sacos aéreos de perus machos com aerossaculite foi coletado para o estudo. Durante o processo de abate, as amostras foram coletadas por meio de swabs e submetidas a três métodos de armazenamento (imediato, congelado ou pré-incubado após congelamento) para posterior comparação das suas eficiências de isolamento. Os gêneros da família Enterobacteriaceae foram identificados pelas séries bioquímicas EPM, MILi e citrato de Simmons. O crescimento bacteriano ocorreu em 43,64% das amostras. Neste estudo, quatro padrões de lesões de aerossaculite foram identificados de acordo com as características patológicas dos sacos aéreos. Os principais gêneros de enterobactérias identificadas foram: Escherichia coli, Citrobacter, Proteus, Edwardsiella, Morganella, Kluyvera, Salmonella e Klebsiella. Foi observado que os graus padronizados como 3 e 4 apresentaram maior variedade de gêneros bacterianos. O armazenamento imediato apresentou maior porcentagem de positividade, 41,82%, no entanto o pré-incubado após congelamento se apresentou mais eficaz em relação à quantidade de colônias.(AU)

The degrees of air sac lesions in turkeys with airsacculitis were standardized, associated with the presence of Enterobacteriaceae isolated from these organs. A total of 110 samples of air sacs from male turkeys with airsacculitis were collected and analyzed. During the slaughtering process, the sample collection was done using swabs and submitted to three storage methods (immediate, frozen, or pre incubated after freezing) for further comparison of their isolated efficiency. The bacterial genera of the family Enterobacteriaceae were identified biochemical series EPM, MILi and Simmons citrate. Bacterial growth occurred in 43.64% of samples. In this study, four patterns of aerossaculitis lesions were identified according to the pathological characteristics of air sacs. The frequencies of the Enterobacteriaceae isolated identified in the samples were: Escherichia coli, Citrobacter, Proteus, Edwardsiella, Morganell, Kluyvera, Salmonella and Klebsiella. Otherwise, it was observed that the levels already standardized as level three and four showed higher variety of genus. The immediate storage showed higher percentage of positivity at 41.82%, however, the pre incubated after freezing showed more efficiency in relation to the quantity of colonies.(AU)

THE ISOLATION AND ANTIMICROBIAL SENSITIVITY OF ASPERGILLUS FUMIGATUS FROM FROZEN RESPIRATORY TISSUES OF PENGUINS FROM ZOOLOGICAL COLLECTIONS IN THE UNITED KINGDOM, 2007-2018.

Fifty-eight frozen postmortem lung and air sac samples were collected from penguins housed at 21 zoological collections throughout the United Kingdom, from 2007 to 2018. Aspergillus fumigatus, a significant respiratory pathogen of penguins in captivity, was isolated from 15 of the 22 penguins with gross lesions. Of the penguins with gross lesions of aspergillosis at postmortem examination, the pathogen was cultured from 63.6% (15 of 22) of frozen samples. Aspergillus fumigatus was cultured from 2.7% (1 of 36) of tissues collected from penguins without gross lesions at postmortem. Additionally, of 18 fresh samples that cultured A. fumigatus at the time of postmortem, 15 samples (83%) yielded isolates that were successfully cultured from frozen tissue. Minimum inhibitory concentration (MIC) data demonstrated that all isolates were susceptible to terbinafine and voriconazole, and all were resistant to itraconazole, using published MIC cutoff values. Comparison isolates from fresh tissues had identical antimicrobial susceptibility to isolates from the same tissues after being frozen. This study demonstrates that A. fumigatus can be isolated from frozen respiratory tissues of penguins, even after freezing for more than 10 yr.

Epicoccum nigrum-induced respiratory infection in a wild Eurasian scops owl (Otus scops).

A wild adult Eurasian scops owl (Otus scops), which was unable to fly, was rescued. Physical examination revealed a sticky exudate around the glottis. Heterophilic leukocytosis was identified through complete blood count, and radiography revealed a marked elevated density of posterior air sacs and inner cavities in both sides of the humerus and femur. Fungal cultures of samples taken from the owl suggested a respiratory fungal infection. Through molecular typing, the fungus was identified as Epicoccum nigrum. The owl was treated with oral itraconazole and broad-spectrum antibiotics. After one month, the inner cavities of pneumatic bones were slightly distinguishable by radiography and the owl started to fly well. Two months later, the air sac and all pneumatic bones displayed normal appearance.

In-depth analysis of swim bladder-associated microbiota in rainbow trout (Oncorhynchus mykiss).

Our knowledge regarding microbiota associated with the swim bladder of physostomous, fish with the swim bladder connected to the esophagus via the pneumatic duct, remains largely unknown. The goal of this study was to conduct the first in-depth characterization of the swim bladder-associated microbiota using high-throughput sequencing of the V4 region of the 16 S rRNA gene in rainbow trout (Oncorhynchus mykiss). We observed major differences in bacterial communities composition between swim bladder-associated microbiota and distal intestine digesta microbiota in fish. Whilst bacteria genera, such as Cohnella, Lactococcus and Mycoplasma were more abundant in swim bladder-associated microbiota, Citrobacter, Rhodobacter and Clavibacter were more abundant in distal intestine digesta microbiota. The presumptive metabolic function analysis (PICRUSt) revealed several metabolic pathways to be more abundant in the swim bladder-associated microbiota, including metabolism of carbohydrates, nucleotides and lipoic acid as well as oxidative phosphorylation, cell growth, translation, replication and repair. Distal intestine digesta microbiota showed greater abundance of nitrogen metabolism, amino acid metabolism, biosynthesis of unsaturated fatty acids and bacterial secretion system. We demonstrated swim bladder harbors a unique microbiota, which composition and metabolic function differ from microbiota associated with the gut in fish.

Candidalysin activates innate epithelial immune responses via epidermal growth factor receptor.

Candida albicans is a fungal pathobiont, able to cause epithelial cell damage and immune activation. These functions have been attributed to its secreted toxin, candidalysin, though the molecular mechanisms are poorly understood. Here, we identify epidermal growth factor receptor (EGFR) as a critical component of candidalysin-triggered immune responses. We find that both C. albicans and candidalysin activate human epithelial EGFR receptors and candidalysin-deficient fungal mutants poorly induce EGFR phosphorylation during murine oropharyngeal candidiasis. Furthermore, inhibition of EGFR impairs candidalysin-triggered MAPK signalling and release of neutrophil activating chemokines in vitro, and diminishes neutrophil recruitment, causing significant mortality in an EGFR-inhibited zebrafish swimbladder model of infection. Investigation into the mechanism of EGFR activation revealed the requirement of matrix metalloproteinases (MMPs), EGFR ligands and calcium. We thus identify a PAMP-independent mechanism of immune stimulation and highlight candidalysin and EGFR signalling components as potential targets for prophylactic and therapeutic intervention of mucosal candidiasis.

Contaminated feed-borne Bacillus cereus aggravates respiratory distress post avian influenza virus H9N2 infection by inducing pneumonia.

Avian influenza virus subtype H9N2 is identified in chickens with respiratory disease while Bacillus cereus (B. cereus) has been frequently isolated from chicken feed in China. However, the roles of co-infection with these two pathogens remain unclear. In the present study, SPF chicks were intragastrically administered with 108 CFU/mL of B. cereus for 7 days and then inoculated intranasally with 100 EID50 of H9N2 three days later. Alternatively, chickens were initially inoculated with H9N2 and then with B. cereus for one week. Post administration, typical respiratory distress persisted for 5 days in both co-infection groups. Gizzard erosions developed in the groups B. cereus/H9N2 and B. cereus group on 7th day while in group H9N2/B. cereus on 14th day. More importantly, both air-sac lesions and lung damage increased significantly in the co-infection group. Significant inflammatory changes were observed in the B. cereus group from day 7 to day 21. Moreover, higher loads of H9N2 virus were found in the co-infected groups than in the H9N2 group. Newcastle Disease Virus (NDV) specific antibodies were decreased significantly in the H9N2/B. cereus group compared to the B. cereus and the B. cereus/H9N2 groups. Nonspecific IgA titers were reduced significantly in the B. cereus group and the H9N2/B. cereus group compared to the control group. In addition to this, lower lymphocyte proliferation was found in the con-infection groups and the H9N2 group. Hence, feed-borne B. cereus contamination potentially exacerbates gizzard ulceration and aggravates H9N2-induced respiratory distress by inhibiting antibody-mediated immunity and pathogen clearance. Thus controlling the B. cereus contamination in poultry feed is immediately needed.

Dose-dependent differential resistance of inbred chicken lines to avian pathogenic Escherichia coli challenge.

Avian pathogenic E. coli (APEC) cause severe respiratory and systemic disease. To address the genetic and immunological basis of resistance, inbred chicken lines were used to establish a model of differential resistance to APEC, using strain O1 of serotype O1:K1:H7. Inbred lines 72, 15I and C.B12 and the outbred line Novogen Brown were inoculated via the airsac with a high dose (107 colony-forming units, CFU) or low dose (105 CFU) of APEC O1. Clinical signs, colibacillosis lesion score and bacterial colonization of tissues after high dose challenge were significantly higher in line 15I and C.B12 birds. The majority of the 15I and C.B12 birds succumbed to the infection by 14 h post-infection, whilst none of the line 72 and the Novogen Brown birds developed clinical signs. No difference was observed after low dose challenge. In a repeat study, inbred lines 72 and 15I were inoculated with low, intermediate or high doses of APEC O1 ranging from 105 to 107 CFU. The colonization of lung was highest in line 15I after high dose challenge and birds developed clinical signs; however, colonization of blood and spleen, clinical signs and lesion score were not different between lines. No difference was observed after intermediate or low dose challenge. Ex vivo, the phagocytic and bactericidal activity of lung leukocytes from line 72 and 15I birds did not differ. Our data suggest that although differential resistance of inbred lines 72, 15I and C.B12 to APEC O1 challenge is apparent, it is dependent on the infectious dose. Research Highlights Lines 15I and C.B12 are more susceptible than line 72 to a high dose of APEC O1. Differential resistance is dose-dependent in lines 15I and 72. Phagocytic and bactericidal activity is similar and dose independent.

Serosurvey of Avian metapneumovirus, Orithobacterium rhinotracheale, and Chlamydia psittaci and Their Potential Association with Avian Airsacculitis.

Seasonal outbreaks of airsacculitis in China's poultry cause great economic losses annually. This study tried to unveil the potential role of Avian metapneumovirus (AMPV), Ornithobacterium rhinotracheale (ORT) and Chlamydia psittaci (CPS) in avian airsacculitis. A serological investigation of 673 breeder chickens and a case-controlled study of 430 birds were undertaken. Results showed that infection with AMPV, ORT, and CPS was highly associated with the disease. The correlation between AMPV and CPS were positively robust in both layers and broilers. Finally, we determined the co-infection with AMPV, ORT, and CPS was prevalent in the sampled poultry farms suffering from respiratory diseases and the outbreak of airsacculitis was closely related to simultaneous exposure to all three agents.

Assessment of Mycoplasma gallisepticum vaccine efficacy in a co-infection challenge model with QX-like infectious bronchitis virus.

Mycoplasma gallisepticum (MG) is the primary cause of chronic respiratory disease in poultry. We investigated the protective efficacy of the live-attenuated ts-11 and 6/85 MG vaccines against a local MG strain and, in order to enhance signs and mimic a typical field situation, we co-infected birds with a virulent strain of QX-like infectious bronchitis virus (IBV). Both vaccines showed similar ability to protect infected chickens from clinical signs, although ts-11 performed slightly better. Despite the lower protection against clinical disease, 6/85-vaccinated birds had significantly (P ≤ 0.05) lower tracheal lesion scores and mucosal thickness at day 28 post-vaccination (7 days post-challenge [dpc] with MG, 2 dpc IBV) and day 31 post-vaccination (10 dpc MG challenge, 5 dpc IBV) compared to ts-11 vaccinated birds, but these difference was not significant at day 33 (12 dpc MG, 7 dpc IBV). Pathogen infection and replication was assessed by qPCR, and the 6/85 vaccine produced a more significant (P ≤ 0.05) reduction in MG replication in the lungs, kidneys and livers but enhanced late replication in bursae and caecal tonsils. In contrast, the ts-11 vaccine had a more pronounced reductive effect on replication in tracheas, air sacs, bursae and heart at days 28 and 31, yet increased replication in lungs. Interestingly, both vaccines provided non-specific protection against IBV challenge. The co-challenge model provided useful data on vaccine efficacy, especially on days 31 and 33, and tracheas, lungs, air sacs, kidneys, liver and caecal tonsils were the best organs to assess.

Swim bladder mycosis in pretty tetra (Hemigrammus pulcher) caused by Exophiala pisciphila and Phaeophleospora hymenocallidicola, and experimental verification of pathogenicity.

Spontaneous invasive and chronic disseminated mycosis affected Hemigrammus pulcher kept in a public aquarium, and infection was manifested by inappetence, exophthalmia, erratic swimming, eroded scales, anaemia of the gills and abdominal distension. Internally, there was a grossly swollen swim bladder with a thickened wall filled with a dark mass. The body cavities contained a clear, light amber fluid and a swollen intestine which was full of a watery fluid containing small gas bubbles. Histopathology revealed a granulomatous inflammatory response with fungal hyphae in the lumen and wall of the swim bladder, hepatopancreas, spleen and kidneys with signs of nephrohydrosis. Exophiala pisciphila and Phaeophleospora hymenocallidicola were isolated from the swim bladder, abdominal cavity and gastrointestinal tract. The exogenous source of infection was probably the ample wooden decoration and plants inside the aquarium. Koch's postulates were fulfilled by re-isolation of both fungal species from fish artificially infected under laboratory conditions. As P. hymenocallidicola is less capable of defence against phagocytosis, E. pisciphila probably played a major role. Severe clinical manifestations with 100% mortality developed in two fish species infected by E. pisciphila. A significant increase in the plasma levels of amino acids was observed as a result of the activation of proteolysis.

Air sacculitis in three rhesus macaques (Macaca mulatta) and one Japanese macaque (M. fuscata).

Bacterial infection of the laryngeal air sacs (air sacculitis) is infrequently reported in nonhuman primates, where it leads to chronic respiratory disease. It is particularly uncommon in macaques; however, we report here suppurative air sacculitis with extension to adjacent cervical tissues in three rhesus macaques and one Japanese macaque. Staphylococcus aureus, Streptococcus sp., and an anaerobic bacterium were isolated.

High-virulence CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from commercial turkeys.

This study reports the high-virulence phylogenetic backgrounds of CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from turkeys sent to slaughter and condemned by airsacculitis in Brazil. Among 300 air sac samples, seven E. coli strains produced plasmid-mediated CMY-2-type AmpC, of which three carried also the blaCTX-M-2 Extended Spectrum Beta-Lactamase encoding gene. Interestingly, the transfer of the blaCMY-2 gene was positive for three E. coli strains, being associated with the presence of IncI1 plasmids. The complete sequence of the representative pJB10 plasmid revealed that the blaCMY-2 gene was within a transposon-like element in the classical genetic environment consisting of tnpA-blaCMY-2-blc-sugE structure. This plasmid with 94-kb belonged to the sequence type (ST) 12 among IncI1 plasmids, which has been associated with the worldwide spread of blaCMY-2 among Salmonella enterica and E. coli. Furthermore, to the best of our knowledge, this is the first complete sequence of a CMY-2-encoding plasmid derived from an Escherichia coli isolated from food-producing animals in Latin America.

Efficacy of gamithromycin against Ornithobacterium rhinotracheale in turkey poults pre-infected with avian metapneumovirus.

Ornithobacterium rhinotracheale is an avian respiratory pathogen that affects turkeys. The objective of this study was to evaluate the clinical efficacy of gamithromycin (GAM) against O. rhinotracheale in turkeys. The birds were inoculated oculonasally with 10(8) colony-forming units (cfu) of O. rhinotracheale, preceded by infection with avian metapneumovirus. In addition to a negative (CONTR-) and a positive control group (CONTR+) there were two treated groups administered GAM (6 mg/kg) either subcutaneously (GAM SC) or orally (GAM PO) by administration as a single bolus at one-day post-bacterial infection (p.b.i.). From the start of the avian metapneumovirus infection until the end of the experiment, the turkeys were examined clinically and scored daily. In addition, tracheal swabs were collected at several days p.b.i. Necropsy was performed at 4, 8 and 12 days p.b.i. to evaluate the presence of gross lesions, and to collect trachea and lung tissue samples and air sac swabs for O. rhinotracheale quantification. The clinical score of the GAM SC group showed slightly lower values and birds recovered earlier than those in the GAM PO and CONTR+ groups. O. rhinotracheale cfus were significantly reduced in tracheal swabs of the SC group between 2 and 4 days p.b.i. At necropsy, CONTR+ showed higher O. rhinotracheale cfu in lung tissues compared to the treated groups. Moreover, at 8 days p.b.i. only the lung samples of CONTR+ were positive. In conclusion, the efficacy of GAM against O. rhinotracheale was demonstrated, especially in the lung tissue. However, the PO bolus administration of the commercially available product was not as efficacious as the SC bolus.

A zebrafish larval model reveals early tissue-specific innate immune responses to Mucor circinelloides.

Mucormycosis is an emerging fungal infection that is clinically difficult to manage, with increasing incidence and extremely high mortality rates. Individuals with diabetes, suppressed immunity or traumatic injury are at increased risk of developing disease. These individuals often present with defects in phagocytic effector cell function. Research using mammalian models and phagocytic effector cell lines has attempted to decipher the importance of the innate immune system in host defence against mucormycosis. However, these model systems have not been satisfactory for direct analysis of the interaction between innate immune effector cells and infectious sporangiospores in vivo. Here, we report the first real-time in vivo analysis of the early innate immune response to mucormycete infection using a whole-animal zebrafish larval model system. We identified differential host susceptibility, dependent on the site of infection (hindbrain ventricle and swim bladder), as well as differential functions of the two major phagocyte effector cell types in response to viable and non-viable spores. Larval susceptibility to mucormycete spore infection was increased upon immunosuppressant treatment. We showed for the first time that macrophages and neutrophils were readily recruited in vivo to the site of infection in an intact host and that spore phagocytosis can be observed in real-time in vivo. While exploring innate immune effector recruitment dynamics, we discovered the formation of phagocyte clusters in response to fungal spores that potentially play a role in fungal spore dissemination. Spores failed to activate pro-inflammatory gene expression by 6 h post-infection in both infection models. After 24 h, induction of a pro-inflammatory response was observed only in hindbrain ventricle infections. Only a weak pro-inflammatory response was initiated after spore injection into the swim bladder during the same time frame. In the future, the zebrafish larva as a live whole-animal model system will contribute greatly to the study of molecular mechanisms involved in the interaction of the host innate immune system with fungal spores during mucormycosis.

Evaluation of the egg transmission and pathogenicity of Mycoplasma gallisepticum isolates genotyped as ts-11.

Live Mycoplasma gallisepticum vaccines are used for the control of respiratory disease, egg production losses and egg transmission associated with M. gallisepticum infection in long-lived poultry. The first field case of apparent increased virulence and vertical transmission of ts-11, a live M. gallisepticum vaccine, has been reported. In that study a M. gallisepticum isolate from the broiler progeny of ts-11-vaccinated breeders was genotyped as ts-11 by sequence analysis of four different genetic targets and Random Amplified Polymorphic DNA and found to be significantly more virulent than ts-11 vaccine. The objective of the current study was to evaluate the rate of egg transmission and pathogenicity of ts-11 vaccine and isolates recovered from ts-11-vaccinated breeders (K6222B) and their broiler progeny (K6216D) which had been genotyped as ts-11. Groups of 28-week-old specific pathogen-free chickens at 87% average weekly egg production were inoculated with sterile broth media (negative controls), ts-11 vaccine, K6222B, K6216D or R strain (positive controls) by eye-drop and aerosol. K6216D transmitted via the egg at an average rate of 4.0% in the third and fourth weeks post-infection, while egg transmission of K6222B and ts-11 vaccine was not detected. M. gallisepticum was isolated from the air sacs, ovaries and oviducts of hens infected with K6216D and K6222B, but not from those infected with ts-11 vaccine. K6216D and K6222B both induced respiratory signs and significantly more tracheal colonization and more severe tracheal and air sac lesions than ts-11 vaccine (P ≤ 0.05). There were no substantial differences in the egg production of ts-11, K6216D and K6222B infected groups. These results provide the first conclusive evidence of transovarian transmission of an isolate genotyped as ts-11 and indicate that isolates genotyed as ts-11 vary in their virulence and ability to transmit via the egg.

Variations in the morphology of Rhizomucor pusillus in granulomatous lesions of a Magellanic penguin (Spheniscus magellanicus).

This report presents a new case of mucormycosis encountered in penguin characterized by morphological variation of hyphae and presence of sporangia with numerous sporangiospores. A 4.5-year-old Magellanic penguin (Spheniscus magellanicus) died after exhibiting anorexia, poor nutritional condition and dyspnea. Multiple nodular lesions were observed in the thoracic and abdominal regions. Histopathologically, hyphae of various sizes were seen in the lungs, air sac and nodular lesions. Myriad sporangiospores and several sporangia were observed in/around the bronchi or parabronchi. The very narrow and short hyphae in the nodules were not consistent with the characteristics of Mucorales. However, for most hyphae, including those in the nodules, sporangiospores and sporangia, immunohistochemistry revealed Mucorales-positive reactions. In addition, these fungi were identified as Rhizomucor pusillus by gene analysis.