1
|
Pees M, Brockmann M, Steiner N, Marschang RE. Salmonella in reptiles: a review of occurrence, interactions, shedding and risk factors for human infections. Front Cell Dev Biol 2023; 11:1251036. [PMID: 37822870 PMCID: PMC10562597 DOI: 10.3389/fcell.2023.1251036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/11/2023] [Indexed: 10/13/2023] Open
Abstract
Salmonella are considered a part of the normal reptile gut microbiota, but have also been associated with disease in reptiles. Reptile-associated salmonellosis (RAS) can pose a serious health threat to humans, especially children, and an estimated 6% of human sporadic salmonellosis cases have been attributed to direct or indirect contact with reptiles, although the exact number is not known. Two literature searches were conducted for this review. The first evaluated reports of the prevalence of Salmonella in the intestinal tracts of healthy reptiles. Salmonella were most commonly detected in snakes (56.0% overall), followed by lizards (36.9%) and tortoises (34.2%), with lower detection rates reported for turtles (18.6%) and crocodilians (9%). Reptiles in captivity were significantly more likely to shed Salmonella than those sampled in the wild. The majority of Salmonella strains described in reptiles belonged to subspecies I (70.3%), followed by subspecies IIIb (29.7%) and subspecies II (19.6%). The second literature search focused on reports of RAS, revealing that the highest number of cases was associated with contact with turtles (35.3%), followed by lizards (27.1%) and snakes (20.0%). Reptiles associated with RAS therefore did not directly reflect prevalence of Salmonella reported in healthy representatives of a given reptile group. Clinical symptoms associated with RAS predominantly involved the gastrointestinal tract, but also included fever, central nervous symptoms, problems with circulation, respiratory symptoms and others. Disease caused by Salmonella in reptiles appears to be dependent on additional factors, including stress, inadequate husbandry and hygiene, and other infectious agents. While it has been suggested that reptile serovars may cause more severe disease than human-derived strains, and some data is available on invasiveness of individual strains in cell culture, limited information is available on potential mechanisms influencing invasiveness and immune evasion in reptiles and in RAS. Strategies to mitigate the spread of Salmonella through reptiles and to reduce RAS focus mostly on education and hygiene, and have often been met with some success, but additional efforts are needed. Many aspects regarding Salmonella in reptiles remain poorly understood, including the mechanisms by which Salmonella persist in reptile hosts without causing disease.
Collapse
Affiliation(s)
- Michael Pees
- Department of Small Mammal, Reptile and Avian Diseases, University of Veterinary Medicine Hannover, Hanover, Germany
| | | | - Natalie Steiner
- Department of Small Mammal, Reptile and Avian Diseases, University of Veterinary Medicine Hannover, Hanover, Germany
| | | |
Collapse
|
2
|
Soliman SA, Abd-Elhafeez HH, Mohamed NE, Alrashdi BM, Alghamdi AAA, Elmansi A, Salah AS, El-Gendy SAA, Rutland CS, Massoud D. Morphological and cytochemical characteristics of Varanus niloticus (Squamata, Varanidae) blood cells. Microsc Res Tech 2023; 86:600-613. [PMID: 36722417 DOI: 10.1002/jemt.24298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/21/2022] [Accepted: 01/13/2023] [Indexed: 02/02/2023]
Abstract
Varanus niloticus is a lizard residing within the Varanidae family. To date no studies detailing its blood morphology and characteristics have been conducted. This study used histologically stained blood and bone marrow samples to visualize the cells and their characteristics. The erythrocytes were nucleated, these nuclei were located in the middle of the elliptical cells. Hemoglobin filled the erythrocyte cytoplasm. Eosinophils were large cells with lobed nuclei and spherical acidophilic granules. Large granulocytes called heterophils were present and characterized by their fusiform/pleomorphic cytoplasmic granules. Small spherical granulocytes, known as basophils, presented with round, deeply stained metachromatic granules that gave the cytoplasm a dusty or cobblestoned appearance which was able to cover the nucleus, which in turn had an unusual shape. Thrombocytes ranged in shape from ellipsoidal to fusiform. They featured an elliptical, centrally located nucleus and a pale cytoplasm, with small vacuoles, and fine acidophilic granulation. The smallest variety of non-granular leukocytes was the lymphocytes. Their cytoplasm was sparse, finely granular, light blue, had tiny cytoplasmic projections, featuring a high nucleus: cytoplasm ratio. Larger and smaller sized populations of lymphocytes were distinguished, with the larger cells similar in size to azurophils. In general, the pleomorphic monocytes were the biggest mononuclear leucocytes, displaying cytoplasmic projections. Their nuclei were ovoid, kidney- or bean-shaped, with vacuolated and granular cytoplasms. Round cells were common among the monocytic azurophils, and they had a granular cytoplasm, and their nuclei were typically eccentric. The present research identifies the cell types and morphologies within the Varanus niloticus. HIGHLIGHTS: H&E, PAS, toluidine blue, methylene blue, and Safranin O stains provided morphological and morphometric descriptions of Varanus niloticus blood cells from blood smears and bone marrow. The Varanus niloticus had nucleated erythrocytes and white blood cells, mostly granulocytes (heterophils, eosinophils, and basophils) and mononuclear cells (azurophils, lymphocytes, and monocytes). Aquatic vertebrate Varanus niloticus had larger erythrocytes than terrestrial counterparts. Blood cell morphological and cytochemical features were similar to other reptilian species, with some species-specific differences, which likely accommodate differing environmental conditions. These results may help clinical researchers track the pathological conditions and support conservation of these wild animals.
Collapse
Affiliation(s)
- Soha A Soliman
- Department of Histology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Hanan H Abd-Elhafeez
- Department of Cell and Tissues, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Nor-Elhoda Mohamed
- Faculty of Science, Biomedicine Branch, University of Science & Technology in Zewail City, Cairo, Egypt
| | - Barakat M Alrashdi
- Biology Department, College of Science, Jouf University, Sakaka, Saudi Arabia
| | - Abdullah A A Alghamdi
- Department of Biology, Faculty of Science, Al-Baha University, Al-Baha, Saudi Arabia
| | - Ahmed Elmansi
- Biology Department, Faculty of Science, King Khalid University, Abha, Saudi Arabia.,Zoology Department, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Abdallah S Salah
- Department of Aquaculture, Faculty of Aquatic and Fisheries Sciences, Kafrelsheikh University, Kafrelsheikh, Egypt.,Institute of Aquaculture, University of Stirling, Stirling, UK
| | - Samir A A El-Gendy
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - Catrin S Rutland
- School of Veterinary Medicine and Science, Faculty of Medicine and Health Science, University of Nottingham, Nottingham, UK
| | - Diaa Massoud
- Biology Department, College of Science, Jouf University, Sakaka, Saudi Arabia.,Department of Zoology, Faculty of Science, Fayoum University, Fayoum, Egypt
| |
Collapse
|
3
|
Piewbang C, Wardhani SW, Poonsin P, Yostawonkul J, Chai-In P, Lacharoje S, Saengdet T, Vasaruchapong T, Boonrungsiman S, Kongmakee P, Banlunara W, Rungsipipat A, Kasantikul T, Techangamsuwan S. Epizootic reptilian ferlavirus infection in individual and multiple snake colonies with additional evidence of the virus in the male genital tract. Sci Rep 2021; 11:12731. [PMID: 34135426 PMCID: PMC8208991 DOI: 10.1038/s41598-021-92156-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/07/2021] [Indexed: 12/27/2022] Open
Abstract
Reptilian ferlavirus, a pathogen of serious concern in snakes, has been reported in Western countries, but little is known about its prevalence in Thailand, where many snake breeding farms are located. In this study, we investigated the reptilian ferlavirus via swab samples derived from 49 diseased snakes and 77 healthy snakes as well as tissue samples taken from nine dead snakes from five independent snake farms. Using molecular detection, we found the ferlavirus in 8.16% of diseased snakes, but not in healthy snakes. Out of nine farmed snakes, eight snakes derived from four farms were found to be positive. Four complete genome sequences of the ferlavirus were successfully obtained and phylogenetically clustered to the highly pathogenic ferlavirus. Tissue tropism of the ferlavirus was identified in various epithelial cell types using the in situ hybridization technique. Interestingly, the hybridization signals were strongly labeled in the male genital tract. Transmission electron microscopy was used to support the ferlaviral localization in the male genital tract. This study provides the first evidence of ferlavirus localization in the male genital tract and contributes to the knowledge about ferlavirus epidemiology, indicating that there needs to be further awareness and elucidation regarding vertical transmission of reptilian ferlavirus.
Collapse
Affiliation(s)
- Chutchai Piewbang
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.,Animal Virome and Diagnostic Development Research Group, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Sabrina Wahyu Wardhani
- Animal Virome and Diagnostic Development Research Group, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.,The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Panida Poonsin
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.,Animal Virome and Diagnostic Development Research Group, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Jakarwan Yostawonkul
- The International Graduate Course of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Poowadon Chai-In
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani, 12120, Thailand
| | - Sitthichok Lacharoje
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Thanyarat Saengdet
- Siam Serpentarium, Siam Park Recreation Co., Ltd., Bangkok, 10520, Thailand
| | - Taksa Vasaruchapong
- Snake Farm, Queen Saovabha Memorial Institute, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Suwimon Boonrungsiman
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani, 12120, Thailand
| | - Piyaporn Kongmakee
- The Zoological Park Organization under The Royal Patronage of H.M. The King, Bangkok, 10800, Thailand
| | - Wijit Banlunara
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Anudep Rungsipipat
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Tanit Kasantikul
- Clemson Veterinary Diagnostic Center, Clemson University, Columbia, SC, 29229, USA
| | - Somporn Techangamsuwan
- Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand. .,Animal Virome and Diagnostic Development Research Group, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
| |
Collapse
|
4
|
Comolli JR, Divers SJ. Respiratory Diseases of Snakes. Vet Clin North Am Exot Anim Pract 2021; 24:321-340. [PMID: 33892890 DOI: 10.1016/j.cvex.2021.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Respiratory abnormalities in snakes are a common clinical presentation in zoologic medical practice. There are often compounding issues involving translocation and substandard husbandry that can predispose to infectious and noninfectious causes of respiratory disease. Endoscopic evaluation of the respiratory tract and the collection of biopsies for histopathology and microbiology is preferred but may only be available from the specialist. Alternatively, transtracheal lavage for cytology and microbiology is a practical method for most practitioners. A variety of bacterial, fungal, viral, and parasitic infections, as well as noninfectious diseases have been reported. Accurate diagnosis dictates specific therapy, which increases the likelihood of successful treatment.
Collapse
Affiliation(s)
- Jessica R Comolli
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, 2200 College Station Road, Athens, GA 30677, USA
| | - Stephen J Divers
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, 2200 College Station Road, Athens, GA 30677, USA.
| |
Collapse
|
5
|
Abstract
Between June and October 2013, 26 snakes of six viperid species kept in two adjoining rooms died ( n = 16) or were euthanized on medical (1) or welfare grounds (9). Two were from the main zoo collection, but the other 24 had been imported and quarantined for a minimum of 6 mo. Four of those that died and the single snake euthanized on medical grounds showed minor signs of respiratory disease prior to death, and five were weak, lethargic, and/or poor feeders. Frequent postmortem findings among all snakes were poor body condition (18) and respiratory disease (13). Seventeen cases were examined histologically, and pneumonia, sometimes with air sacculitis and/or tracheitis, was present in 15 individuals. Lung samples from 24 snakes were ferlavirus polymerase chain reaction (PCR) positive, and one of the two snakes for which only liver was available was also positive. The negative liver sample was from a snake that died of sepsis following anesthesia for surgical removal of a spindle cell sarcoma. Correlation with antemortem PCR testing of glottal and cloacal swabs in five cases was poor (sensitivity = 40%). Immunohistochemistry (IHC) for ferlaviruses on the tissues of 13 PCR-positive cases showed positive labeling in 7 only. Tissues samples from 22 ferlavirus PCR-positive snakes were examined for Chlamydia species by PCR, and 9 were positive, although DNA sequencing only confirmed two of three tested as Chlamydia pneumoniae. Immunohistochemistry for Chlamydia pneumoniae of seven cases (two Chlamydiales PCR positive, one of which was sequenced as C. pneumoniae, plus five negative) confirmed the Chlamydia PCR results. These two Chlamydiales PCR and IHC positive snakes were ferlavirus PCR positive, but IHC negative suggesting that, even though a ferlavirus was the predominant cause of the outbreak, in a few cases death may have been due to chlamydiosis with ferlavirus present, but not acting as the primary pathogen.
Collapse
|
6
|
Pees M, Schmidt V, Papp T, Gellért Á, Abbas M, Starck JM, Neul A, Marschang RE. Three genetically distinct ferlaviruses have varying effects on infected corn snakes (Pantherophis guttatus). PLoS One 2019; 14:e0217164. [PMID: 31163032 PMCID: PMC6548425 DOI: 10.1371/journal.pone.0217164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 05/06/2019] [Indexed: 01/10/2023] Open
Abstract
Ferlaviruses are important pathogens in snakes and other reptiles. They cause respiratory and neurological disease in infected animals and can cause severe disease outbreaks. Isolates from this genus can be divided into four genogroups–A, B, and C, as well as a more distantly related sister group, “tortoise”. Sequences from large portions (5.3 kb) of the genomes of a variety of ferlavirus isolates from genogroups A, B, and C, including the genes coding the surface glycoproteins F and HN as well as the L protein were determined and compared. In silico analyses of the glycoproteins of genogroup A, B, and C isolates were carried out. Three isolates representing these three genogroups were used in transmission studies with corn snakes (Pantherophis guttatus), and clinical signs, gross and histopathology, electronmicroscopic changes in the lungs, and isolation of bacteria from the lungs were evaluated. Analysis of the sequences supported the previous categorization of ferlaviruses into four genogroups, and criteria for definition of ferlavirus genogroups and species were established based on sequence identities (80% resp. 90%). Analysis of the ferlavirus glycoprotein models showed parallels to corresponding regions of other paramyxoviruses. The transmission studies showed clear differences in the pathogenicities of the three virus isolates used. The genogroup B isolate was the most and the group A virus the least pathogenic. Reasons for these differences were not clear based on the differences in the putative structures of their respective glycoproteins, although e.g. residue and consequential structure variation of an extended cleavage site or changes in electrostatic charges at enzyme binding sites could play a role. The presence of bacteria in the lungs of the infected animals also clearly corresponded to increased pathogenicity. This study contributes to knowledge about the structure and phylogeny of ferlaviruses and lucidly demonstrates differences in pathogenicity between strains of different genogroups.
Collapse
Affiliation(s)
- Michael Pees
- Department for Birds and Reptiles, University Teaching Hospital, University of Leipzig, Leipzig, Germany
- * E-mail:
| | - Volker Schmidt
- Department for Birds and Reptiles, University Teaching Hospital, University of Leipzig, Leipzig, Germany
| | - Tibor Papp
- Institute for Veterinary Medical Research, Centre for Agricultural Research, the Hungarian Academy of Sciences, Budapest, Hungary
| | - Ákos Gellért
- Institute for Veterinary Medical Research, Centre for Agricultural Research, the Hungarian Academy of Sciences, Budapest, Hungary
| | - Maha Abbas
- Institute for Environmental and Animal Hygiene, University of Hohenheim, Stuttgart, Germany
| | | | - Annkatrin Neul
- Department for Birds and Reptiles, University Teaching Hospital, University of Leipzig, Leipzig, Germany
| | | |
Collapse
|