Staphylococcus spp. as part of the microbiota and as opportunistic pathogen in free-ranging black-tuffed marmosets (Callithrix penicillata) from urban areas: Epidemiology, antimicrobial resistance, and pathology.

BACKGROUND: Marmosets (Callithrix sp.), including black-tuffed marmosets (C. penicillata), are neotropical primates that can be highly adapted to urban environments, especially parks and forested areas near cities. Staphylococcus spp. are part of the microbiota of many different hosts and lead to opportunistic severe infection. Isolates from wild animals can be resistant to antimicrobial drugs. However, there are a few studies that evaluated Staphylococcus spp. in neotropical primates. The goal of this study was to evaluate Staphylococcus spp. isolated from free-ranging black-tuffed marmosets. METHODS: Marmosets were captured in six urban parks. After sedation, skin and rectal swabs and feces were sampled. Staphylococcus spp. isolates were identified by MALDI-ToF and their antimicrobial susceptibility was determined. RESULTS: Over 30% of captured individuals were positive for Staphylococcus spp., and S. aureus was the most isolated species followed by Mammaliicoccus (Staphylococcus) sciuri. With the exception of the marmoset subjected to necropsy, none of the other had lesions, which supports that notion that Staphylococcus spp. are members of the microbiota, but also opportunistic pathogens. Most isolates were susceptible to all antimicrobials tested; however, one isolate of S. epidermidis was resistant to multiple antimicrobials (penicillin, cefoxitin, ciprofloxacin, clindamycin, and erythromycin). We considered S. aureus as the main staphylococci to colonize black-tuffed marmosets. CONCLUSIONS: Black-tuffed marmosets can be colonized by several Staphylococcus species, most frequently by S. aureus, and the majority of isolates were sensible to the antimicrobials tested. One S. epidermidis isolate was considered multidrug resistant.

Molecular detection of Sarcocystis sp. in a kept under human care black capuchin monkey (Sapajus nigritus., Goldfuss 1809) with necrotizing encephalitis.

A senile male black capuchin monkey (Sapajus nigritus) kept under human care in a Zoo was found dead after 2 weeks presenting signals of weight loss and hyporexia. Histopathological revealed a necrotizing encephalitis. Although it was not observed microscopically, Sarcocystis sp infection was detected in brain tissue from molecular assays. These infections have been rarely described in neotropical primates, particularly associated with tissue lesions.

Granulomatous meningoencephalitis and blindness associated with Mycobacterium tuberculosis complex infection in a senile female chimpanzee (Pan troglodytes).

A 40-year old female chimpanzee (Pan troglodytes) developed hyporexia, weight loss, followed by progressive and complete blindness. Tomography demonstrated an intracranial mass in the rostroventral brain involving the optic chiasm, with a presumptive diagnosis of neoplasm. However, histopathology revealed a granulomatous meningoencephalitis, and tissue samples tested positive for Mycobacterium tuberculosis.

Heavy metals bioaccumulation in free-ranging South American rattlesnakes (Crotalus durissus) in Southeastern Brazil.

Anthropogenic activities are the main sources of soil, air, and water pollution by metals, including cadmium (Cd), lead (Pb), chromium (Cr), the metalloid arsenic (As), magnesium (Mg), zinc (Zn), and copper (Cu). The goal of this study was to assess the presence and concentration of toxic (As, Cd, Pb, and Cr) and essential metals (Mg, Zn, and Cu) in the liver and kidneys from 96 free-ranging rattlesnakes (Crotalus durissus) from Minas Gerais (Brazil). Bioaccumulation of Cd and Pb were significantly higher in males and heavier rattlesnakes (those with body weight above the average of the study population). Average ± standard deviations of Cd, Pb, Cr, Cu, Mg, Zn, and As in the general population (n = 96) were 3.19 ± 2.52; 5.98 ± 8.49; 0.66 ± 1.97; 3.27 ± 2.85; 776.14 ± 2982.92; 27.44 ± 29.55; and 0.32 ± 1.46; respectively. Bioaccumulation of some metals correlated positively with changes in hematologic and serum biochemical parameters. Results of this study were contrasted with previous studies assessing metal bioaccumulation in other species of terrestrial or aquatic snakes. Considering their position in the food chain and the broad range of bioaccumulation of both toxic and essential metals observed in this study, rattlesnakes may function as highly relevant biological sentinels for environmental pollution.

Comparative study on alginate/chitosan microcapsules and Montanide ISA 61 as vaccine adjuvants in mice.

Selection of adjuvant to be combined with the antigen is an extremely important point for formulating effective vaccines. The aim of this study was to evaluate reactogenicity, levels of IgM, IgG and subclasses (IgG1, IgG2b and IgG3), and protection elicited by vaccine formulations with association of chitosan coated alginate or Montanide ISA 61 with γ-irradiated Brucella ovis. The alginate/chitosan biopolymers as well as the Montanide ISA 61 emulsion elicited intense and long-lasting local response, especially when associated with the antigen. However, Montanide ISA 61 induced less intense reactogenicity when compared to alginate/chitosan. Furthermore, γ-irradiated B. ovis with Montanide ISA 61 induced higher levels of IgG2b an important marker of cellular immune response. In conclusion, Montanide ISA 61 resulted in milder reactogenicity when compared to the alginate/chitosan, while it induced a high IgG2b/IgG1 ratio compatible with a Th1 profile response.

Acute, fatal Sarcocystis falcatula infection in rose-ringed parakeets (Psittacula krameri).

Sarcocystosis is an important avian disease that affects several intermediate host species. Birds not endemic from Americas, like Old World psittacine species, appear to be more susceptible to lethal infection than New World psittacine species. The aim of this study was to investigate the sudden death of rose-ringed parakeets (Psittacula krameri) in an exotic private parrot's aviary. Macroscopically, the most prevalent findings were severe lung congestion, slight superficial myocardial hemorrhagic lesions, enlarged liver and congestion of meningeal vessels. The initial diagnosis of sarcocystosis was made in all birds by microscopic observations of intravascular pulmonary schizonts, as well hepatitis, myocarditis, and nephritis. Immunohistochemistry for detection of Sarcocystis sp. antigen revealed an intense immunoreactivity in the lungs. Molecular identification of Sarcocystis falcatula were obtained by nested PCR and sequencing of amplified fragments of internal transcribed spacer 1 (ITS1) and three surface antigen-coding genes (SAG2, SAG3 and SAG4). SAG-based phylogenies showed a close relatedness of the isolate described here and S. falcatula previously detected in naturally infected native birds, which suggests that the isolates that affected ringnecks are a common isolate that circulates in Brazil.

Canine Pyometra: A Short Review of Current Advances.

Pyometra, characterized by the accumulation of purulent exudate in the uterus, is the most prevalent reproductive disease in canines. While the disease often begins with mild local symptoms, it can escalate into peritonitis, sepsis, and multi-organ dysfunction, thereby posing a significant threat to life. Despite the high incidence and recognized significance of canine pyometra, gaps persist in our understanding of its epidemiology, etiology, and pathogenesis. Recent studies have, however, broadened our comprehension of this disease, shedding light on potential new infection sources, etiologies, and the application of clinical predictive biomarkers and new therapeutic protocols. This study aimed to review the current understanding of canine pyometra, with particular emphasis on the latest research concerning its etiology and epidemiology. Furthermore, it addressed key research questions and proposed directions for future investigations into various facets of canine pyometra.

ANTIMICROBIAL SUSCEPTIBILITY OF STAPHYLOCOCCUS SPP. ISOLATED FROM FELIDS AND CANIDS IN BELO HORIZONTE ZOO, BRAZIL.

The epidemiology of Staphylococcus spp. has become a major concern among humans and animals due to increasing antimicrobial resistance and frequent reports of infection. Despite the importance of animals as reservoirs for staphylococci, little is known about the epidemiology of Staphylococcus spp. in most nondomestic species, including canids and felids. This study evaluated the frequency, distribution, and patterns of antimicrobial resistance of staphylococcal species isolated from captive felids and canids from Belo Horizonte Zoo, Brazil. Rectal, oral, and nasal swabs from apparently healthy maned wolves (Chrysocyon brachyurus, n= 7), a lion (Panthera leo, n = 1), jaguars (Panthera onca, n = 3), and one swab of a cougar (Puma concolor) with an ear infection were streaked onto mannitol salt agar. Colonies identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, polymerase chain reaction for the Staphylococcus intermedius group (SIG), and 16S rRNA gene sequencing. Isolates were subjected to antimicrobial susceptibility tests and Staphylococcus pseudintermedius strains were subjected to multilocus sequence typing. Staphylococcus species were isolated from 24 of the 34 samples (70.6%). Among the isolated strains, S. pseudintermedius and Staphylococcus felis were the most frequent species (41.7 and 25%, respectively). Five novel sequence types were identified among the S. pseudintermedius isolates. Resistance to tetracycline (7/24, 29.2%) or penicillin (6/23, 26.1%) was significantly higher than the other antimicrobial agents tested (P < 0.05). One isolate, Staphylococcus nepalensis, was positive for mecA and resistant to five antimicrobials, and was thus classified as multidrug-resistant. The present work suggests that maned wolves are natural hosts of SIG and also reports the isolation of S. felis in sick and healthy, captive, nondomestic carnivores. The isolated staphylococci were susceptible to most classes of antimicrobials tested. However, the multidrug-resistance capability of an S. nepalensis strain reinforces the hypothesis that felids and canids act as reservoirs of pathogens with antimicrobial resistance.

Cell and Tissue Tropism of Brucella spp.

Brucella spp. are facultatively intracellular bacteria that can infect, survive, and multiply in various host cell types in vivo and/or in vitro. The genus Brucella has markedly expanded in recent years with the identification of novel species and hosts, which has revealed additional information about the cell and tissue tropism of these pathogens. Classically, Brucella spp. are considered to have tropism for organs that contain large populations of phagocytes such as lymph nodes, spleen, and liver, as well as for organs of the genital system, including the uterus, epididymis, testis, and placenta. However, experimental infections of several different cultured cell types indicate that Brucella may actually have a broader cell tropism than previously thought. Indeed, recent studies indicate that certain Brucella species in particular hosts may display a pantropic distribution in vivo. This review discusses the available knowledge on cell and tissue tropism of Brucella spp. in natural infections of various host species, as well as in experimental animal models and cultured cells.

Chylothorax associated with pulmonary compressive atelectasis in an emperor tamarin (Saguinus imperator).

Chylothorax is the accumulation of lymph in the thoracic cavity, and it has never been reported in neotropical primates. An emperor tamarin died and at necropsy chylothorax associated with pulmonary compressive atelectasis was diagnosed. Idiopathic chylothorax can be a cause of respiratory insufficiency and death in tamarins.

Vaccination with Formulation of Nanoparticles Loaded with Leishmania amazonensis Antigens Confers Protection against Experimental Visceral Leishmaniasis in Hamster

Visceral leishmaniasis (VL) is a fatal disease caused by the protozoa Leishmania infantum for which dogs are the main reservoirs. A vaccine against canine visceral leishmaniasis (CVL) could be an important tool in the control of human and CVL by reducing the infection pressure of L. infantum. Despite the CVL vaccine available on the market, the Brazilian Ministry of Health did not implement the use of it in their control programs. In this sense, there is an urgent need to develop more efficient vaccines. In this study, the association between two polymeric nanoformulations, (poly (D, L-lactic) acid (PLA) polymer) loading Leishmania amazonensis antigens, was evaluated as a potential immunobiological agent against VL using golden hamsters as an experimental model. The results indicated that no significant adverse reactions were observed in animals vaccinated with LAPSmP. LAPSmP presented similar levels of total anti-Leishmania IgG as compared to LAPSmG. The LAPSmP and LAPSmG groups showed an intense reduction in liver and spleen parasitic load by qPCR. The LAPSmP and LAPSmG vaccines showed exceptional results, indicating that they may be promising candidates as a VL vaccine.

Polyarteritis nodosa in a captive common wooly monkey (Lagothrix lagotricha) associated with intestinal necrosis, peritonitis, and sepsis.

Polyarteritis nodosa is an idiopathic necrotizing vasculitis that affects small to medium-sized arteries. We describe a case of polyarteritis nodosa in a captive common wooly monkey (Lagothrix lagotricha) associated with transmural intestinal necrosis and secondary peritonitis. This condition must be considered for differential diagnosis of segmental arteritis in neotropical primates.

Lafora's disease in a free-ranging toco toucan (Ramphastos toco) with neurologic disease

Lafora's disease is a genetic disease associated to mutations in genes that encodes laforin and malin, which results in intracellular polyglucan storage. The present report describes a case of Lafora's disease in a toco toucan with episodes of incoordination and myoclonus that resulted in traumatic lesions and fracture of the left hindlimb. The bird was euthanized and submitted to necropsy. Microscopically there were abundant PAS-positive and diastasis-resistant Lafora's inclusion bodies in neurons in the cerebellum, supporting the diagnosis of Lafora's disease.(AU)

Urethral obstruction secondary to Staphylococcus felis chronic urethritis and hepatoid gland adenoma in a captive ocelot (Leopardus pardalis)

A male adult ocelot (Leopardus pardalis) kept under human care developed anuria, which progressed to death. Grossly, the urinary bladder was markedly dilated and filled with red discolored urine containing blood clots. In addition, the animal had a hepatoid cell adenoma adjacent to the urethra, which likely caused partial urethral occlusion. Microscopically, there was a predominantly neutrophilic, fibrinous and hemorrhagic urethritis, cystitis, and pyelonephritis with intralesional gram-positive cocci. Microbiologic culture followed by MALDI-TOF MS analysis resulted in the identification of isolates from the urine and urethra as Staphylococcus felis.(AU)

Infectious diseases of neotropical primates

Neotropical primates are represented by more than 200 species and subspecies distributed in five families. Considering that some of these species are considered endangered, disease investigation in these populations is critical for conservation strategies. Therefore, an increasing number of studies and publications on this topic became available in the past few years. This review deals with infectious diseases of neotropical primates, with focus on free-ranging animals, including those caused by bacterial, viral, protozoal, metazoan, or mycotic infectious organisms, with particular emphasis on gross and microscopic lesions associated with these diseases. In addition, a few relevant unpublished cases of infection by Staphylococcus spp., Streptococcus spp., E. coli and Pseudomonas spp. were included in this review.(AU)

Transmission of Escherichia coli Causing Pyometra between Two Female Dogs.

Despite its clinical relevance, the pathogenesis of canine pyometra remains poorly understood. To date, it is recognized as a non-transmissible infectious disease. In this study, the simultaneous occurrence of pyometra and Escherichia coli in two cohabitant female dogs underwent in-depth investigation due to the hypothesis of transmission between these animals. Two 5-year-old Chow Chow dogs (namely, dogs 23 and 24-D23 and D24) were referred to a veterinary hospital with suspected pyometra. Both animals showed prostration, anorexia, and purulent vulvar discharge over a 1-week period. After ovariohysterectomy, uterine tissue, uterine contents, and rectal swabs were collected for histopathological and microbiological analysis. Uterine histology demonstrated purulent material and multifocal necrosis with endometrial ulceration, and a morphological diagnosis of pyometra was confirmed. Furthermore, E. coli from the same phylogroup (B2) and positive for the same virulence factors with the same antimicrobial susceptibility profile was isolated from the uterine contents of both dogs and the rectum of D23. Conversely, the E. coli strains recovered from D24 differed in phylogroup (one isolate), virulence factors (all three isolates), and antimicrobial susceptibility (all three isolates). Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) suggested that all isolates from the uterine content of both dogs and the rectal swab of D23 were 100% the same, but different from all isolates in the rectal swab of D24. One isolate from the uterine content of each animal as well as rectal swabs were subjected to whole-genome sequencing (WGS). Both whole-genome multilocus sequence typing(wgMLST) and single-nucleotide polymorphism (SNP) analysis supported the hypothesis that the isolates from the uterine content of both animals and the rectal swab of D23 were clonal. Taken together, these clinical features, pathology, microbiology, and molecular findings suggest, to the best of our knowledge, the first transmission of E. coli associated with pyometra between two animals. These results could impact the management of sites where several females cohabit in the same local area such as kennels.

Nanoformulations with Leishmania braziliensis Antigens Triggered Controlled Parasite Burden in Vaccinated Golden Hamster (Mesocricetus auratus) against Visceral Leishmaniasis.

Leishmaniasis is a widespread vector-borne disease in Brazil, with Leishmania (Leishmania) infantum as the primary etiological agent of visceral leishmaniasis (VL). Dogs are considered the main reservoir of this parasite, whose treatment in Brazil is restricted to the use of veterinary medicines, which do not promote a parasitological cure. Therefore, efficient vaccine development is the best approach to Canine Visceral Leishmaniasis (CVL) control. With this in mind, this study used hamsters (Mesocricetus auratus) as an experimental model in an anti-Leishmania preclinical vaccine trial to evaluate the safety, antigenicity, humoral response, and effects on tissue parasite load. Two novel formulations of nanoparticles made from poly(D, L-lactic) acid (PLA) polymer loading Leishmania braziliensis crude antigen (LB) exhibiting two different particle sizes were utilized: LBPSmG (570 nm) and LBPSmP (388 nm). The results showed that the nanoparticles were safe and harmless to hamsters and were antigenic with the induction in LBSap, LBPSmG, and LBPSmG groups of total anti-Leishmania IgG antibodies 30 days after challenge, which persists 200 days in LBSap and LBPSmP. At the same time, a less pronounced hepatosplenomegaly in LBSap, LBPSmG, and LBPSmP was found when compared to control groups, as well as a less pronounced inflammatory infiltrate and granuloma formation in the spleen. Furthermore, significant reductions of 84%, 81%, and 90% were observed in spleen parasite burden accessed by qPCR in the LBSap, LBPSmG, and LBPSmP groups, respectively. In this way, LBSap, LBPSmG, and LBPSmP formulations showed better results in vaccinated and L. infantum-challenged animals in further reducing parasitic load in the spleen and attenuating lesions in liver and splenic tissues. This results in safe, harmless nanoformulation vaccines with significant immunogenic and infection control potential. In addition, animals vaccinated with LBPSmP had an overall reduction in parasite burden in the spleen, indicating that a smaller nanoparticle could be more efficient in targeting antigen-presenting cells.

Avian mycobacteriosis in a naturally infected captive nocturnal curassow (Nothocrax urumutum)

A senile female nocturnal curassow (Nothocrax urumutum) kept under human care was found dead. Grossly, the lungs were congested and had a nodule with 2.0 cm in diameter adhered to the left lung. Histologically, there were multifocal to coalescent areas of necrosis characterized by deposition of amorphous and eosinophilic material with large amount of cellular debris, surrounded by numerous epithelioid macrophages, multinucleated Langhans giant cells, occasional lymphocytes and plasma cells. Ziehl-Neelsen stained sections demonstrated myriad of intralesional alcohol-acid resistant bacilli (BAAR). DNA extracted from lung samples were evaluated by nested polymerase chain reaction resulting in mycobacterial DNA identification. This is the first reported case of mycobacteriosis in a nocturnal curassow.(AU)

PARASITOLOGIC AND PATHOLOGIC STUDY OF FREE-RANGING SOUTH AMERICAN RATTLESNAKES (CROTALUS DURISSUS TERRIFICUS) IN BRAZIL.

This study assesses parasitism and pathologic manifestations in free-ranging Crotalus durissus terrificus. A total of 96 rattlesnakes from the State of Minas Gerais (southeast Brazil) were necropsied between September 2019 and February 2020. Granulomatous gastritis affected 48% (46 of 96) of the snakes evaluated, which were associated with the ascaridid nematodes Ophidascaris sp. and Hexametra sp. Other nematodes found included Kalicephalus costatus costatus and Kalicephalus inermis inermis (Diaphanocephalidae; 7%, 7 of 96) in the intestines, Serpentirhabdias sp. (Rhabdiasidae; 18%, 17 of 96) in the lungs, and Hastospiculum sp. (Diplotriaenidae; 2%, 2 of 96) encapsulated in the serosa of the mesentery. Larval cestodes, probably spargana of Spirometra sp. (Diphyllobothriidae; 2%, 2 of 96), were found in the skeletal muscle and unidentified acanthocephalan cystacanths (Oligacanthorhynchidae; 5%, 5 of 96) in the subcutis and coelomic cavity. The pentastome Porocephalus crotali (Porocephalidae; 2%, 2 of 96) was also found in the lungs. Microscopically, intestinal disease was caused by Sarcocystis sp. (7%, 7 of 96), Cryptosporidium sp. (1%, 1 of 96), and Entamoeba sp. (1%, 1 of 96) and fungi (7%, 7 of 96). In addition, hemoparasites such as Hepatozoon spp. (23%, 22 of 96) and Trypanosoma sp. (1%, 1 of 96) were observed in blood smears. This study expands the knowledge of diseases, parasites, and other infectious agents affecting free-ranging C. durissus terrificus in Brazil.

Pathology and epidemiology of fatal toxoplasmosis in free-ranging marmosets (Callithrix spp.) from the Brazilian atlantic forest.

Toxoplasmosis is an important zoonotic disease that affects a wide range of warm-blooded host species. Neotropical primates (New World Primates; NWP) are highly susceptible, developing a lethal acute systemic disease. Toxoplasmosis in free-ranging NWP is poorly described, with only a few studies based on serosurveys. Herein we performed a retrospective study focusing on the epidemiology and pathology of toxoplasmosis among 1,001 free-ranging marmoset (Callithrix spp.) deaths from the Brazilian Atlantic Forest. This study included marmosets necropsied at the Instituto Municipal de Medicina Veterinária Jorge Vaitsman (IJV) from January 2017 to July 2019, which were found dead from all regions in the State of Rio de Janeiro. Histopathology, immunohistochemistry, and transmission electron microscopy were performed to better characterize toxoplasmosis in this free-ranging population. All samples were also tested for Yellow Fever Virus (YFV) RT-qPCR by the official diagnostic service. A total of 1,001 free-ranging marmosets were included in this study, with 16 (1.6%) cases of lethal Toxoplasma gondii infections identified both as individual cases and in outbreaks. Presence of infection was not associated with sex, age, geographical distribution, or year of death, and no co-infection with YFV was observed. The main pathological feature in these cases was random necrotizing hepatitis with detection of intralesional T. gondii zoites in all infected cases. Interstitial pneumonia rich in alveolar foamy macrophages and fibrin deposition, necrotizing myocarditis and necrotizing splenitis were also pathological features in affected marmosets. Therefore, toxoplasmosis was considered the cause of death in 1.6% of free-ranging marmosets in this retrospective series, including some cases associated with outbreaks. Necrotizing random hepatitis was a consistent pathological finding in affected cases and sampling of liver should be ensured from Callitrichid post mortem cases.