Shahram Jamshidi

Canine visceral leishmaniasis: Asymptomatic infected dogs as a source of L. infantum infection

Clinically infected dogs have been identified as the main reservoir hosts of visceral leishmaniasis (VL) caused by Leishmania infantum in the Mediterranean region. The objective of this study was to determine the potential of asymptomatic infected dogs compared with symptomatic ones as a source of L. infantum infection to golden hamster. For this purpose, anti-Leishmania antibodies were detected with direct agglutination test (DAT) in 13 symptomatic (7 seropositive =>or=1:320) and 53 asymptomatic (9 seropositive =>or=1:320 and 44 seronegative =<1:320) ownership dogs. DNA of Leishmania sp. was extracted from skin and peripheral blood tissues of each dog and tested by PCR. Sixty-six Syrian golden hamsters (Mesocricetus auratus) were used for the determination of infectivity and pathogenicity of L. infantum, isolated from the dogs. We used the internal transcribed spacer 2 (ITS 2) rDNA sequence analysis. The results showed that 22 and 11 out of 66 inoculated golden hamsters were positive by PCR and parasitological examinations, respectively. From 22 PCR positive hamsters, 17 were related to asymptomatic dogs and 5 were from symptomatic ones. There was no significant difference between symptomatic and asymptomatic dogs in producing Leishmania infection in the susceptible animal model (P=0.66). Smears and cultures of 5 dogs from 13 symptomatic dogs (38.5%) and 6 dogs from 53 asymptomatic ones (11.3%) were found to be positive at parasitological examination. All the L. infantum isolates from symptomatic and asymptomatic dogs were similar in sequencing. In conclusion, asymptomatic infected dogs as well as symptomatic ones can harbor L. infantum in their blood and skins which are virulent and infectious for inoculated golden hamster.

Identification and antimicrobial susceptibility patterns of bacteria causing otitis externa in dogs

Bacterial agents are considered important pathogens causing external otitis in dogs. It is essential to carry out bacterial culture and antimicrobial susceptibility test in the case of otitis externa, particularly for chronic or recurring cases. Sterile swab samples were obtained from terminal part of vertical ear canals of 74 dogs with otitis externa for cytology, bacterial culture and antimicrobial susceptibility test. Cytologic smears were stained using Gram and Giemsa staining methods. Aerobic bacterial culture performed on blood agar and MacConkey agar. Among total number of 92 isolated bacteria, 68 were Staphylococcus intermedius. Other isolated bacteria included: Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Pasteurella canis, and six other species of coagulase-negative Staphylococcus. Antimicrobial susceptibility test were performed for all isolated bacteria using 14 antibiotics. Based on the results of this study, all isolated Staphylococcus spp. were sensitive to amikacin, enrofloxacin, and rifampin, and had low resistance to gentamicin, cephalothin and ceftriaxone. More than half of gram-positive isolates were resistant to penicillin and ampicillin. Generally, all isolated gram-negative bacteria, were sensitive to amikacin and enrofloxacin, and had low resistance to ceftriaxone and gentamicin. They were highly resistant to penicillin, eythromycin, and cephalothin. Regarding the results of this study, in cases of uncomplicated otitis externa, it is possible to select antimicrobial drugs merely based on cytology, but it is recommended to perform bacterial culture and antimicrobial susceptibility test. However, in complicated or refractory cases, antimicrobials should be selected based on bacterial culture and antimicrobial susceptibility test.

Evaluation of Live Recombinant Nonpathogenic Leishmania tarentolae Expressing Cysteine Proteinase and A2 Genes as a Candidate Vaccine against Experimental Canine Visceral Leishmaniasis

Canine Visceral Leishmaniasis (CVL) is a major veterinary and public health problem caused by Leishmania infantum (L. infantum) in many endemic countries. It is a severe chronic disease with generalized parasite spread to the reticuloendothelial system, such as spleen, liver and bone marrow and is often fatal when left untreated. Control of VL in dogs would dramatically decrease infection pressure of L. infantum for humans, since dogs are the main domestic reservoir. In the past decade, various subunits and DNA antigens have been identified as potential vaccine candidates in experimental animal models, but none has been approved for human use so far. In this study, we vaccinated outbreed dogs with a prime-boost regimen based on recombinant L. tarentolae expressing the L. donovani A2 antigen along with cysteine proteinase genes (CPA and CPB without its unusual C-terminal extension (CPB-CTE) and evaluated its immunogenicity and protective immunity against L. infantum infectious challenge. We showed that vaccinated animals produced significantly higher levels of IgG2, but not IgG1, and also IFN-γ and TNF-α, but low IL-10 levels, before and after challenge as compared to control animals. Protection in dogs was also correlated with a strong DTH response and low parasite burden in the vaccinated group. Altogether, immunization with recombinant L. tarentolae A2-CPA-CPB-CTE was proven to be immunogenic and induced partial protection in dogs, hence representing a promising live vaccine candidate against CVL.

Immunological comparison of DNA vaccination using two delivery systems against canine leishmaniasis

Visceral leishmaniasis (VL) is a fatal disease caused by the intracellular protozoan parasite Leishmania infantum. Dogs are the primary reservoirs of this parasite, and vaccination of dogs could be an effective method to reduce its transfer to humans. In order to develop a vaccine against VL (apart from the choice of immunogenic candidate antigens), it is necessary to use an appropriate delivery system to promote a proper antigen-specific immune response. In this study, we compared two vaccine delivery systems, namely electroporation and cationic solid-lipid nanoparticle (cSLN) formulation, to administer a DNA vaccine containing the Leishmania donovani A2 antigen, and L. infantum cysteine proteinases of type I (CPA) and II (CPB) without its unusual C-terminal extension. The protective potencies of these two vaccine delivery systems were evaluated against L. infantum challenge in outbred dogs. Our results show that the administration of pcDNA-A2-CPA-CPB(-CTE)GFP vaccine as a prime-boost by either electroporation or cSLN formulation protects the dogs against L. infantum infection. Partial protection in vaccinated dogs is associated with significantly (p<0.05) higher levels of IgG2, IFN-γ, and TNF-α and with low levels of IgG1 and IL-10 as compared to the control group. Protection was also correlated with a low parasite burden and a strong delayed-type hypersensitivity (DTH) response. This study demonstrates that both electroporation and cSLN formulation can be used as efficient vaccine delivery systems against visceral leishmaniasis.

Effect of Hydrosoluble Chlorine–Mediated Antimicrobial Photodynamic Therapy on Clinical Parameters and Cytokine Profile in Ligature-Induced Periodontitis in Dogs

BACKGROUND Recently, a hydrosoluble chlorine composed of sodium salts chlorine e6, chlorine p6, and purpurine-5 has been shown to be a promising photosensitizer in antimicrobial photodynamic therapy (aPDT). The aim of this study is to evaluate the effects of adjunctive application of hydrosoluble chlorine-mediated aPDT compared with scaling and root planing (SRP) alone on clinical parameters and cytokine levels in gingival crevicular fluid of dogs with experimental periodontitis. METHODS Periodontal disease was induced by placing silk ligatures around both maxillary and mandibular teeth. After establishment of attachment loss, full-mouth SRP was performed in all dogs. One day after SRP, each quadrant randomly received one of the following treatment modalities: hydrosoluble chlorine plus diode laser (wavelength 662 nm, power 100 mW, continuous mode, time of irradiation 20 seconds), hydrosoluble chlorine alone, laser alone, or no adjunctive treatment. The same adjunctive procedure was repeated 1 week later. Clinical parameters including periodontal probing depth, clinical attachment level, and bleeding on probing, as well as crevicular levels of interleukin-1β and tumor necrosis factor-α, were evaluated at baseline, at 3 weeks, and at 3 months after treatment. RESULTS After both 3 weeks and 3 months, all treatment groups showed significant improvement in all clinical and immunologic parameters (P <0.001). No significant differences were found between the four groups with regard to the measured parameters (P >0.05). CONCLUSION Based on the results of this study, adjunctive use of hydrosoluble chlorine-mediated aPDT with the current setting has no additional effect on the clinical parameters or proinflammatory cytokine levels in ligature-induced periodontitis.

The efficacy and safety of long-term Helicobacter species quadruple therapy in asymptomatic cats with naturally acquired infection.

Owing to rising drug-resistant Helicobacter species infections in people and animals, currently therapies are losing their efficacy; therefore, regimens efficacious in the presence of drug resistance are needed. This study assessed the efficacy and safety of a 14-day quadruple Helicobacter species therapy in cats with naturally acquired infection. Thirteen asymptomatic adult stray cats with Helicobacter species infection (identified by analysis of gastric biopsies using polymerase chain reaction and Helicobacter-specific primers) received omeprazole 0.7 mg/kgq 8 h plus amoxicillin 20 mg/kgq 12 h, metronidazole 20 mg/kgq 12 h and clarithromycin 7.5 mg/kgq 12 h, for 14 days. Second molecular analysis of gastric biopsies revealed persistence of Helicobacter species DNA in four cats that were negative on quantitative urease testing, cytology and histopathology. Our results suggest that antibiotic regimens that are effective against Helicobacter pylori in people cannot eradicate Helicobacter species in cats with naturally acquired infection, although transient suppression may occur.

Detection of Helicobacter spp. DNA in the colonic biopsies of stray dogs: molecular and histopathological investigations

BackgroundIn dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other parts of the alimentary system. The incidence of Helicobacter spp. infection in dogs is largely unknown and to our knowledge there are no data about their potential pathogenic role. In light of these considerations, the aims of this study were (i) to assess the prevalence of Helicobacter spp. in colonic biopsies of healthy and symptomatic stray dogs also (ii) we isolate and characterize helicobacters in canine colonic biopsies to compare the commonly used tests for the identification of Helicobacter spp. and to determine the occurrence of these species in dogs.MethodsTissues from fifteen stray dogs (8 males and 7 females, age 6 months –10 years) were used in this study. From each stray dog, multiple colonic biopsies were taken for PCR. Biopsies for PCR of cecum and colon were immediately frozen and stored at -20°C until DNA extraction. Samples for histological examination were fixed in 10% neutral buffered formalin and embedded in paraffin wax.ResultsIn the cecum and colon, Helicobacter spp. DNA was detected in all dogs. H.canis, H.bizzozeronii, H. bilis, H.felis, H.salomonis and H.pylori Identified by specific polymerase chain reaction. Histopathology demonstrated that Helicobacter organisms were localized within the surface mucus and the intestinal crypts. Dogs with heavy Helicobacter spp. colonization were significantly in younger as well as had a higher level of mucosal fibrosis/atrophy than dogs with uncolonized or poorly colonized biopsies (p < 0.05).ConclusionsWe have indicated that the crypts of the cecum and colon of healthy and symptomatic dogs are heavily colonized by Helicobacter spp.. Combined molecular and histological approaches demonstrated that enterohepatic Helicobacter spp. infection is rather common in colonic biopsies of healthy and symptomatic stray dogs, with Helicobacter spp. specialy H. canis, H.bizzozeroni, H.billis, H.felis and H. salomonis identified as the most common species.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1957989294118782.

A survey of ectoparasite infestation in dogs in Tehran, Iran

This survey was conducted to identify and estimate the frequencies of ectoparasites of dogs in Tehran, Iran. A total of 143 dogs attended at the Small Animal Hospital of the Veterinary School, the University of Tehran, were examined for the presence of ectoparasites and dermatological lesions. Ectoparasite specimens and blood samples were sent to parasitology and hematology laboratories, respectively. Ticks were the most frequent ectoparasite (36.4%, 52/143), followed by fleas (29.4%, 42/143), mites (25.9%, 37/143), and lice (8.4%, 12/143). Mixed infestations with two or more ectoparasites were detected in eight dogs. Rhipicephalus bursa was the most frequent ectoparasite in spring and summer. Ectoparasitic infestations were recorded mainly in large breeds and juvenile animals. Eosinophilia was more observed in dogs infested with Sarcoptes scabiei. The most common clinical sign, skin pruritus, was associated with mite and lice infestations. These results indicate that the tick R. bursa was the most prominent species of ectoparasite found in the evaluated group, followed by Ctenocephalides canis and S. scabiei var canis.

Evaluation of Metastatic Cholangiocarcinoma in a Spitz Dog

A 12-year-old spitz breed dog, with progressive neurologic symptoms including seizures, ataxia, mental depression, walking aimlessly and head pressing was referred to Small Animal Hospital of Veterinary Medicine, the University of Tehran. The dog was received Diazepam prior to examination and diagnosis, whereas it died at first day eventually. In physical examination, there was a firm mass with irregular nodular surface, about 8 cm in diameter under the skin of mammary glands region. At necropsy, considerable abdominal ascites, several masses with different sizes throughout liver lobes and on intestinal serosa were observed. According to histological adjectives of biliary epithelium due to firm texture of the tumour masses and numerous mitotic figures the tumour was confirmed as cholangiocarcinoma, and immuniohistochemical results for cytokeratin marker demonstrated such diagnosis.

Report of Theileria annulata and Babesia canis infections in dogs

Piroplasmosis is a zoonotic protozoan disease transmitted by ticks. The full geographical range of canine piroplasms has been found in dogs in the Middle East, parts of Africa, North America, and Europe. Following our studies on molecular detection of piroplasmosis in the south of Iran, we found Theileria annulata in two herd dogs, as well as information on their 18S rRNA gene sequences. Piroplasmosis agents were detected by PCR of 280 blood samples collected from dogs in seven regions of the Shiraz suburbia in southern Iran, between November 2009 and June 2011. Two positive samples from Shiraz were infected with T. annulata, and one sample was infected with Babesia canis. PCR positive samples were further analyzed by sequence analysis. The results of this study reconfirmed that T. annulata are not always as host specific as accepted. This is the first report of T. annulata in herd dogs in southern Iran and the second report of T. annulata in dogs worldwide.