Sensitivity of Entomopathogenic Fungi and Bacteria to Plants Secondary Metabolites, for an Alternative Control of Rhipicephalus (Boophilus) microplus in Cattle

Boophilus (Rhipicephalus) microplus is a one host hard tick widespread in warm climates worldwide, responsible for great economic losses. To avoid resistance in ticks population, induced by the repeated administration of conventional acaricides and/or the presence of residues in the environment in meat and in milk, an alternative approach can be achieved using entomopathogenic microorganisms such as fungi and bacteria, or essential oils (EOs). The aim of the present study was to evaluate the in vitro sensitivity of Beauveria bassiana, Metarhizium anisopliae, Scopulariopsis sp, Bacillus thuringiensis and Proteus mirabilis to Eucalyptus globulus, Lavandula hybrida, Pelargonium graveolens EOs and to their main constituents such as lynalool, linalyl-acetate, geraniol, citronellol and 1,8 cineole. EOs has been chemically characterized by GC-MS. Fungal isolates were tested by a microdilution assay to achieve minimal inhibitory concentration (MIC) of both EOs and main components. The sensitivity of bacteria was evaluated by an agar disk diffusion. The results obtained show the feasibility of an integrate approach for an eco-friendly control of R. microplus by use of both entomopathogenic fungi and P. graveolens EO. L. hybrida could be an interesting alternative when B. bassiana is not employed. Conversely, a combined use of B. thuringiensis and EOs would not be advisable in the integrate control of ticks.

Antibacterial and Antifungal Activity of Essential Oils against Pathogens Responsible for Otitis Externa in Dogs and Cats

Background: Essential oils (EOs) are recommended by some veterinarians to treat otitis externa in pets, but data about their efficacy in scientific literature are very scant. Methods: Nine commercial EOs, from roman chamomile (Anthemis nobilis L.), star anise (Illicium verum), lavender (Lavandula hybrida), litsea (Litsea cubeba (Lour.) Pers.), basil (Ocimum basilicum L.), oregano (Origanum vulgare L. subsp. hirticum), rosemary (Rosmarinus officinalis L.), clary sage (Salvia sclarea L.), and thyme (Thymus vulgaris L.) were tested against bacterial and fungal pathogens previously isolated from dogs and cats with otitis externa. In particular, the analyses were carried out against Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus pseudointermedius, Aspergillus niger, Aspergillus fumigatus, Aspergillus terreus, Candida albicans, Candida tropicalis, Trichosporon sp., and Rhodotorula sp. Results:O. vulgare and S. sclarea showed superior antibacterial activity, even if not against all the strains. Trichosporon sp., C. albicans, and A. terreus were insensitive to most Eos, while other yeasts and molds showed different degrees of sensitivity. In particular, most fungi were inhibited by O. vulgare and R. officinalis. Conclusions: The obtained results suggest that some EOs could be included in treatment as an alternative therapeutic option in bacterial otitis complicated by fungi, in association with conventional drugs.

Experimental infection with Yersinia pseudotuberculosis in European brown hare (Lepus europaeus, Pallas)

OBJECTIVE

To investigate clinicopathological, bacteriological and pathological aspects of an experimental infection with Yersinia pseudotuberculosis (Y. pseudotuberculosis) in hares to verify the efficacy of serology for the in vivo diagnosis. Moreover, the pathogenicity of two Y. pseudotuberculosis strains was investigated in order to detect potential differences.

METHODS

Twelve European brown hares (Lepus europaeus, Pallas) were experimentally infected per os and via conjunctival mucosae with Y. pseudotuberculosis: six subjects were infected with a strain isolated from a naturally infected hare (YpH) and six subjects with a strain isolated from a naturally infected rabbit (YpR). Two hares were used as negative controls. All animals were subjected to clinical, bacteriological and serological examinations during 9 weeks following the infection and, at the end of the control period, subjects still alive were euthanized and submitted to a complete post mortem examination.

RESULTS

All faecal samples collected during the control period were positive for bacteriological examinations and to a PCR for the inv gene of Y. pseudotuberculosis, while only one YpH-infected hare showed a positive haemocultures. From the 2nd to the 9th week post infection (pi), serological analysis revealed specific antibodies with titers ranging from 1:10 to 1:160 in all YpH-infected and two YpR-infected subjects. All the YpH-infected and two YpR-infected hares scored positive for Y. pseudotuberculosis by means of bacteriological investigations. Grossly, suppurative multifocal lesions were detected in liver, spleen, kidney and sub-mandibular lymph nodes in both YpH- and YpR-infected hares and confirmed with histopathology. Pulmonary lesions were observed only in YpH-infected subjects. Immunohistochemistry confirmed the presence of bacterial antigen in all infected animals.

CONCLUSION

Results of this study revealed that YpH strain is more pathogenic for hares than the YpR strain; moreover the serological test performed in this study could be used for the diagnosis of pseudotuberculosis in hares, whereas post mortem diagnosis should be confirmed by means of bacteriological examination, PCR, histopathology and immunohistochemistry.

Serological evidence of exposure to Ehrlichia canis and Anaplasma phagocytophilum in Central Italian healthy domestic cats

The aim of the present survey was to estimate the seroprevalences of Ehrlichia canis and Anaplasma phagocytophilum in the Central Italian feline population. Serum samples of 560 healthy domestic cats were examined by indirect immunofluorescence assay (IFAT), considering an antibody titre of 1:40 as cut-off. Seroprevalences of 6.4% and 4.5% were found for E. canis and A. phagocytophilum, respectively. Adult, mixed breed cats showed seroprevalences higher than younger and purebred subjects, whereas no differences were observed in relation to gender and living conditions.

Mycobacterium avium subspecies hominissuis disseminated infection in a Basset Hound dog

In the current report, a case in Italy of disseminated Mycobacterium avium subsp. hominissuis infection in a dog from an American lineage of Basset Hounds is described. A 2-year-old intact female Basset Hound presented with persistent lymphadenopathy, lameness, and a history characterized by coccidiosis, bacterial gastroenteritis, and alopecia. Lymphadenitis, with macrophages containing a few intracytoplasmic, negative staining, Ziehl-Neelsen-positive bacilli, was detected by a popliteal fine-needle aspirate leading to the diagnosis of mycobacteriosis. Ultrasound and X-ray examinations revealed visceral and mediastinal lymphadenopathy. Because of the extent of the disease, the dog was humanely euthanized. Significant gross abnormalities, such as enlargement of the cranial mediastinal lymph nodes with encapsulated areas of caseous necrosis and generalized lymphadenopathy, were observed at necropsy. Granulomatous lesions were histopathologically detected in the liver and spleen. Ziehl-Neelsen-positive bacilli were observed in all examined lymph node, liver, spleen, lung, and bone marrow smears. Lymph nodes and liver were collected in order to pursue speciation by bacterial culture and molecular biology; multiplex polymerase chain reaction results classified the pathogen as M. avium subsp. hominissuis. Although an immune system deficiency was not investigated, anamnesis suggests that the dog was immunocompromised. Furthermore, the dog came from an American stock of Basset Hound, and for some of this breed, a predisposition to this infection has been hypothesized.

Seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in Italian horses

The aim of the study was to determine the seroprevalence of Leptospira spp. and Borrelia burgdorferi sensu lato in healthy horses living in 7 provinces of central Italy. In the period 2007-2009, sera from 386 horses were tested by microagglutination test (MAT) to detect antibodies to Leptospira spp., employing the following serovars as antigens: Bratislava, Ballum, Canicola, Icterohaemorrhagiae, Grippotyphosa, Hardjo, Pomona, Tarassovi. 3 animals were positive for the serovars Icterohaemorrhagiae, 2 to Bratislava, and 1 to Pomona, for a total 1.5% seroprevalence. All sera were examined by immunofluorence antibody test (IFAT) to reveal anti-B. burgdorferi s.l. antibodies. 94 (24.3%) horses were positive with antibody titres ranging from 1:64 to 1:1,024. The seroprevalence was significantly higher in >10 year-old horses compared to younger subjects. No significant differences in the mean seroprevalence were observed in the respective years. The total mean seroprevalence were strictly related to the environmental conditions of the areas in which the horses lived. No cross-reactions between Leptospira and Borrelia were observed. This is the first serological survey on antibodies to B. burgdorferi s.l. in Italian horses.

Occurrence of Bartonella henselae types I and II in Central Italian domestic cats

Serological and molecular surveys were conducted to determine the occurrence of Bartonella henselae in domestic cats in Central Italy. Samples from 234 pet cats were tested for B. henselae antibodies by indirect immunofluorescence with 78 (33.3%) positive. A PCR assay specific for the Bartonella 16S rRNA gene was carried out on DNA samples extracted from blood of the 234 cats; 26 (11.1%) of the seropositive cats were positive. Two PCR protocols, which discriminate genotypes I and II of B. henselae, were performed on all DNA samples. Sixteen (6.8%) cats were infected by genotype I, 6 (2.5%) by genotype II, and two males (0.8%) by both genotypes. Two female (0.8%) cats which were Bartonella sp. PCR positive, gave negative results with the types I and II PCR. This protocol facilitates the direct and rapid detection of Bartonella DNA in feline blood samples, and differentiates B. henselae genotypes.

Raw milk for sale in Pisa province: biosecurity of dairy farms and hygienic evaluation of milk

Selling raw milk by automatic dispenser on the farm is a good way to increase income. The aim of the present research is to evaluate both the biosecurity of dairy farms in the Pisa province and the hygienic quality of raw milk. Two farms, chosen because of previously analyzed results carried out on animals and milk, were monitored for 9 months according to the regional law DGR 381/2007. The results obtained showed that these farms presented good cattle health status. The raw milk tested was of a satisfactory hygienic quality, with great variability among milk samples in certain parameters, such as somatic cell count. This study confirmed the importance of consistent, ongoing control of safety conditions on dairy farms.

Salmonella enterica isolates from faeces of domestic reptiles and a study of their antimicrobial in vitro sensitivity

From October 2001 to February 2002, the faecal samples of 305 reptiles (165 saurians, 99 ophidians and 41 chelonians) were bacteriologically examined to detect Salmonella enterica. S. enterica was isolated from 73 (23.93%) faecal samples including 44 (60.27%) samples collected from saurians, 15 (20.55%) from chelonians and 14 (19.18%) from ophidians; considering the number of samples taken for each reptile group, S. enterica was isolated from the 36.58% of chelonians, 26.66% of saurians and 14.14% of ophidians. The isolates were distributed among 38 serotypes. Sixty-nine (94.52%) isolates were resistant to erythromycin. About one-third of the isolates was resistant to sulfisoxazole (35.61%), gentamycin (32.88%), amoxycillin (31.51%) and ampicillin (27.40%). All but one of the isolates were sensitive to chloramphenicol. A high percentages of isolates were sensitive to enrofloxacin (84.93%), nitrofurantoin (80.82%), trimethoprim (76.71%) and tetracycline (75.34%).

Prevalence of Leptospira and Brucella antibodies in wild boars (Sus scrofa) in Tuscany, Italy

Five hundred sixty-two blood samples were collected from wild boars (Sus scrofa) shot in six districts of Tuscany, central Italy, between 1997 and 2000. Sera were examined for antibodies specific for Leptospira interrogans by microagglutination test and Brucella spp. by the Rose Bengal test and indirect enzyme-linked immunosorbent assay. Thirty-four (6.0%) samples tested positive for anti-Leptospira antibodies, 29 (5.1%) sera were positive for anti-L. interrogans serovar bratislava antibodies (titres ranging from 1:100-1:400), and 5 (0.9%) sera were positive for anti-L. interrogans serovar icterohaemorrhagiae antibodies (titres 1:100). All the examined sera were negative for anti-Brucella antibodies.

Epidemiology of leptospirosis: observations on serological data obtained by a "diagnostic laboratory for leptospirosis" from 1995 to 2001

Serological data on leptospira infection were reported and discussed. From 1995 to 2001, the blood serum samples of 9885 domestic and wild animals and humans, living in Northern and Central Italy, were examined by the macroagglutination test (MAT) employing bratislava, ballum, canicola, grippotyphosa, icterohaemorrhagiae, pomona, hardjo and tarassovi serovars as antigens. Considering sera with > or = 1:400 antibody titers as positive, 674 (6.81%) animals scored positive. Sheep, horses, pigs and dogs gave the highest number of positive responses, particularly against the serovar bratislava and, for dogs, against icterohaemorrhagiae. The percentages of seropositivity observed in the most important animal species were: 12.13% in ovine (132 positive among 1088 tested animals), 11.40% in horses (107 positive animals among 938), 9.46% in swine (123 positive animals among 1299), 6.36% in dogs (278 positive animals among 4369), 2.39% in wild boars (11 positive animals among 459), 1.39% in deer (2 positive animals among 143), 0.48% in cattle (3 positive animals among 626). Among 250 human sera examined, 14 (5.60%) scored positive.

Serological diagnosis of brucellosis caused by Brucella canis

Blood serum samples from 2,328 dogs were tested to detect antibodies against Brucella canis with the agar gel immunodiffusion (AGID) and 2-mercaptoethanol slide agglutination test (ME-SAT) using Brucella ovis as the antigen. All blood serum samples were also evaluated for antibodies against Brucella abortus and Brucella melitensis using the Rose Bengal test. Twentyfive (1.07%) of the sera evaluated were considered positive with AGID test. Only 4 (16%) of these blood serum samples were positive when evaluated with ME-SAT. The 25 AGID positive samples and 25 AGID negative serum samples were also examined by: the complement fixation test (CFT) using B. ovis hot saline extract (HSE) as the antigen, indirect enzyme linked immunosorbent assay (ELISA) and immunoblotting (IB) using B. canis and B. ovis HSE antigens. Two positive canine sera from culture positive dogs and the serum of an experimentally RM6/66 B. canis-infected rabbit were employed as positive controls and one serum from a known uninfected dog as a negative control. ELISA with B. canis antigen gave 9 (18%) positive results (6 AGID-positive and 3 AGID-negative sera). ELISA performed with B. ovis antigen detected 15 (30%) positive samples (10 AGID-positive, 5 AGID-negative and 8 B. canis ELISA positive sera). IB analysis of known positive controls sera employing B. canis antigen detected bands with molecular weights of 94-80, 64-50, 35, 32-30, 28, 23, 20-18, 15-12 kDa. The same sera tested with B. ovis antigen revealed bands of 35, 32-30, 25, 23, 20-18, 15-12 kDa. No bands were observed with the negative control serum and the 50 canine tested sera.

Cat scratch disease. Survey on the presence of Bartonella henselae among cats of Tuscany

To verify the presence of Bartonella henselae-infection in cats living in Tuscany (central Italy) serological and bacteriological surveys were carried out. The blood serum samples of 427 cats, 254 living in private houses and gardens and 173 in public or private catteries, were tested for anti-B. henselae antibodies by indirect immunofluorescence assay (IFA). Among these samples, 35 were examined by IFA to detect antibodies against Bartonella quintana. Bacteriological examinations were performed on the blood samples, collected in EDTA (ethylene diaminetetraacetic acid), of 18 cats (10 seropositive to B. henselae and 8 negative). From each of the same 18 specimens DNA was extracted and used as template in polymerase chain reaction (PCR). The primers p24E and p12B were employed in the PCR assay to amplify a 296 bp fragment of the Bartonella 16S rRNA gene. IFA detected 98 (22.95%) B. henselae-positive serum samples (40-40.82% from cats living in houses and gardens and 58-59.18% from cats of catteries) at different antibody titers (70 at 1:64 titer, 4 at 1:128, 22 at 1:256, 2 at 1:512). Among the 35 sera tested to detect antibodies against B. quintana, 9 (25.71%) resulted positive at 1:64 titer; all these samples showed higher antibody titers to B. henselae. Out of the 26 negative sera, 20 were negative to B. henselae too and 6 had antibodies against B. henselae at 1:64. Hemocultures gave negative results. PCR scored positive with DNA of 4 B. henselae-seropositive cats, two of which belonged to two children with cat scratch disease (CSD).

Diagnosis of paratuberculosis in naturally infected goats

A survey was carried out to verify if an immunohistochemical method associated with agar gel immunodiffusion (AGID) will establish a firm diagnosis of caprine paratuberculosis. One hundred and thirty-six goats were tested by AGID for antibodies against Mycobacterium avium subsp. paratuberculosis at two different times: the first time 22 (19.1%) were positive and the second time 25 (18%). One seronegative goat with severe diarrhea and 5 seropositive goats, two of which showing similar clinical signs, were sacrificed and necropsied. Samples were taken from small intestine, liver, spleen, mesenteric lymph nodes for bacteriological, histological and immunohistochemical examinations. M.a. paratuberculosis was isolated from intestine samples of 4 seropositive goats and from mesenteric lymph nodes of one seropositive goat; the microorganism was not isolated from samples of one seropositive and the seronegative animals. Ziehl Neelsen staining showed acid-fast bacilli in macrophages of the 5 seropositive animals and the immunohistochemical method for M. a. paratuberculosis detected bacterial antigen in the same samples.

Experimental Brucella ovis infection in mouflon (Ovis musimon)

Brucella ovis was isolated for the first time in Italy in 1994 from the genital organs of two domestic rams. In subsequent years bacteriologic and serologic investigations demonstrated an increasing distribution of this disease in domestic sheep. Mouflon (Ovis musimon) occur in several hilly and mountainous areas of Italy where they can potentially contact domestic sheep. To determine if this species may have a role in the epidemiology of B. ovis, four male and four female mouflon, serologically negative for B. ovis and other Brucella spp., were infected intra-conjunctivally with B. ovis strain BG1/94. Physical examinations, including collection of blood samples for serology and bacteriology, were performed weekly. The animals were euthanized 8 mo postinoculation (p.i.). Samples of retropharyngeal, parotid, and iliac lymph nodes; bone marrow; kidneys; spleen; epididymis; testicle; bulbourethral glands; seminal vesicles; uterus; and oviducts were collected from each animal as appropriate for histopathology and bacteriology. At the time of euthanasia none of the animals exhibited obvious clinical signs of brucellosis. The animals seroconverted 2 wk p.i. and became seronegative 24 wk p.i. Bacterial cultures, including hemocultures, were negative. No lesions due to B. ovis infection were revealed by histologic examinations. Brucella ovis probably did not infect mouflon and this wild sheep is not likely to play a role in the epidemiology of contagious epididymitis caused by B. ovis.

Evaluation of tests employed in serological diagnosis of brucellosis caused by Brucella ovis

A survey was carried out to verify the sensitivity and specificity of various tests (complement fixation test--CF; agar gel immunodiffusion--AGID; indirect enzyme linked immunosorbent assay--ELISA; immunoblotting--IB) employed in the serological diagnosis of brucellosis caused by Brucella ovis. The tests were executed on 44 blood serum samples of rams coming from B. ovis-free flocks, 75 of B. ovis experimentally infected rams and 1139 from rams living in flocks where B. ovis had been previously isolated. All tests were performed using B. ovis hot saline extract (HS) as antigen. Sensitivity results were 97.4% for IB, 98.68% for CF, 100% for AGID and ELISA; specificity was 100% for all methods. Concordance values were 89.62% (CF-AGID), 78.77% (CF-ELISA), 77.74% (AGID-ELISA), 65.45% (IB-CF), 62.93% (IB-ELISA), 67.24% (IB-AGID). IB identified antibodies to antigenic components with molecular weight of 67, 63, 58, 55, 38, 35, 32, 30, 28, 25, 23, 21, 20-18 kDa (proteins) and 15-12 kDa (rough lipopolysaccharide).

An immunoblotting technique for the serodiagnosis of brucellosis by Brucella ovis

An immunoblotting (IB) technique was developed for the serodiagnosis of brucellosis caused by Brucella ovis. Immunoblotting was performed, using a B. ovis HS (hot saline extract) antigen, on 44 blood serum samples which came from rams belonging to known brucella-free flocks, 114 samples originating from ten experimentally B. ovis infected rams and 100 from rams of naturally B. ovis infected flocks. No bands were noted on any of the 44 serum samples which originated from known negative flocks. Sera from naturally and experimentally infected rams identified antibodies to antigenic components with molecular masses of 67, 63, 58, 55, 38, 35, 32, 30, 28, 25, 23, 21, 20-18 (proteins) and 15-12 (RLPS) kDa.

Epididymitis by Brucella ovis: experimental infection in virgin ram lambs

Ten sexually immature rams were experimentally infected with Brucella ovis, to verify the antibody kinetics and its localization in urinary and genital tracts. All animals became positive to the complement fixation test from the 2nd post infection (p.i.) week and reached the maximum titre (1:256) on the 4th p.i. week. Bacteriemia was demonstrated on 3rd, 4th and 5th p.i. weeks. Two animals, respectively slaughtered 11 and 13 weeks after the infection, showed macroscopic and microscopic genital lesions and the etiologic agent was cultured from their urine and genital organs.