María Teresa Tejedor-Junco

Isolation of nitrate-reductase positive Corynebacterium pseudotuberculosis from dromedary camels

Corynebacterium pseudotuberculosis is the causative organisms of caseous lymphadenitis (pseudotuberculosis) in sheep and goats (Lloyd et al. 1990; Lindsay and Lloyd 1991). This condition is characterized by abscessation of one or more lymph nodes, but sometimes presents as pneumonia, hepatitis, mastitis, arthritis, orchitis and subcutaneous abscesses. Corynebacterium pseudotuberculosis is associated with lymphadenitis in horses and ulcerative lymphangitis in cattle (Sutherland et al. 1993; Aleman et al. 1996; Miers and Ley 1980) and affects rarely in human beings (Peel et al. 1997). Pseudotuberculosis occurs worldwide and it has also been described in camels in several countries (Wernery and Kaaden 2002). Two biotypes of C. pseudotuberculosis, based on nitrate-reducing ability, have been reported and these biotypes can be correlated with different genotype patterns (Songer et al. 1988; Sutherland et al. 1996). Isolates from sheep and goats were nitrate negative whereas those from horses were nitrate positive. Reactions from cattle isolates were variable. Strains that reduce nitrate are referred as biotype equi and strains that fail to do so are referred as biotype ovis. Barakat et al. (1984) found two serotypes referred as type I and type II which corresponded with nitrate reductase negative and positive strains, respectively. In camels, only the serotype I (biotype ovis) has been described in the available literature (Wernery and Kaaden 2002). A study on pseudotuberculosis in camels was carried out in the Canary Islands, using 13 affected dromedaries, and isolating C. pseudotuberculosis biotype ovis in all cases (Tejedor et al. 2004). This communication presents the isolation of Corynebacterium pseudotuberculosis nitrate reductase positive from two camels belonging to the same herd and located in Canaries.

Presence of antibodies but no evidence for circulation of MERS-CoV in dromedaries on the Canary Islands, 2015.

In 2012, a new betacoronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV), was identified in humans. Several studies confirmed dromedary camels to be a potential reservoir and a source for human infection. Camels located on the Canary Islands were included in those studies and ca 10% of them were positive for MERS-CoV-specific antibodies. However, these findings could not be correctly interpreted because epidemiological information was not provided. Thus, further investigations were necessary to clarify these results. A total of 170 camels were investigated in this survey, of which seven (4.1%) were seropositive by ELISA. Epidemiological information revealed that all seropositive camels had been imported from Africa 20 or more years prior. We conclude that seropositive camels had contact with MERS-CoV in Africa and that there is no shedding of the virus among camels or people around the farms on the Canary Islands. However, the presence of antibodies in the camel herds should be monitored.

The role of wild rodents in the transmission of Trypanosoma evansi infection in an endemic area of the Canary Islands (Spain).

Trypanosoma evansi was diagnosed for the first time in camels in the Canary Islands in 1997. Several sanitary measures including treatment of infected animals were taken; however, nowadays a little area is still infected. In order to determine possible reservoirs 138 wild rodents were trapped, 64 of them in the infected farms and the remaining 74 in other areas. The captured species were Rattus rattus (24), Rattus norvegicus (69) and Mus musculus domesticus (45). Serological (CATT/T. evansi), parasitological (micro-Hematocrit Centrifugation technique and stained smears) and molecular (PCR) methods for T. evansi and T. lewisi were used as diagnostic methods. None of the examined rodents was positive for T. evansi; 18, however, showed motile trypanosomes at micro-Hematocrit Centrifugation technique and resulted positive for T. lewisi by PCR. The results would suggest that the studied rodent species would not play a relevant role in the epidemiology of T. evansi infection in Canaries.

Morphological and biometrical features of Trypanosoma evansi isolates from an outbreak in mainland Spain.

According to several authors, Trypanosoma evansi is a monomorphic trypanosome found exclusively in slender intermediate forms, although additional studies have revealed that many strains present stumpy forms on rare occasions. In a recent T. evansi outbreak in mainland Spain, several atypical forms were observed in blood smear examinations. Molecular procedures were then necessary to confirm the causal agent. Morphological and biometric measures were taken to characterize the different forms of T. evansi. In contrast to published information, the results of this study would indicate that biometrically distinct T. evansi could also be found in the same farm and even in the same animal species. These data could be useful for many trypanosomes endemic areas of the world where molecular methods are not commonly available.

Multiple abscesses caused by Salmonella enterica and Corynebacterium pseudotuberculosis in a dromedary camel

A rare case of arthritis, peri-arthiritis and pleurits associated with Salmonella enterica and Corynebacterium pseudotuberculosis infection in a dromedary camel is reported. Articular infections caused by Non-typhoidal Salmonella have been exceptionally described in human medicine. To our knowledge, this would be the first description of articular infections associated with Non-thyphoidal Salmonella in other mammals than humans. Possible pathogenesis of the infection is discussed.

Type I β-lactamases ofEnterobacter cloacae and resistance to β-lactam antibiotics

The interaction of type-I β-lactamases fromEnterobacter cloacae with diverse β-lactam compounds was examined. The ability of penicillin and cefoxitin to induce β-lactamase production in this strain was assessed. The effect of β-lactamase inhibitors was measured on β-lactamase extracts and on intact cells.E. cloacae 78 strain is a stably derepressed mutant showing limited susceptibility to a number of antibiotics except imipenem. Imipenem would therefore be the appropiate choice for therapy of infections caused by stably derepressed mutants ofEnterobacter sp. producing type-I β-lactamases.

Stomoxys calcitrans as possible vector of Trypanosoma evansi among camels in an affected area of the Canary Islands, Spain

INTRODUCTION Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a small area of the Archipelago. To date, the disease has exclusively affected camel herds, and has not been detected in any other animal hosts. However potential vectors of Trypanosoma evansi must be identified. METHODS One Nzi trap was placed on a camel farm located in the infected area for a period of one year. RESULTS Two thousand five hundred and five insects were trapped, of which Stomoxys calcitrans was the sole hematophagous vector captured. CONCLUSIONS Stomoxys calcitrans could be exclusively responsible for the transmission of Trypanosoma evansi among camels in the surveyed area, as other species do not seem to be infected by S. calcitrans in the presence of camels.

Outbreaks of Keratoconjunctivitis in a Camel Herd Caused by a Specific Biovar of Moraxella canis

ABSTRACT Two tributyrin hydrolysis-negative Moraxella isolates obtained in cases of keratoconjunctivitis in Camelus dromedarius in the Canary Islands showed highest degrees of 16S rRNA gene sequence similarity to Moraxella canis. A level of DNA relatedness to the M. canis type strain of 79% confirmed the identity of the isolates as a tributyrin hydrolysis-negative biovar of M. canis.

Doxycycline treatment for Dirofilaria immitis in dogs: impact on Staphylococcus aureus and Enterococcus antimicrobial resistance

Doxycycline is an antibiotic that, in addition to the classic antibacterial use, is also prescribed to fight parasitic diseases, like heartworm disease in dogs. Despite the concern that the overuse of this antibiotic may decrease susceptibility of clinically important bacteria, the consequences of the prolonged doxycycline therapy in heartworm-infected dogs have never been studied before. We have analyzed the impact of this therapy on Staphylococcus aureus and Enterococcus antimicrobial resistance. In this study, 17 heartworm-infected dogs (10 that had completed the doxycycline treatment and 7 dogs that had not yet begun) were included. Twenty-four isolates of Staphylococcus aureus were obtained from two locations of each dog. After treatment, 73.3% of isolates were resistant to at least one antibiotic but only 22.2% of isolates before treatment. Most of doxycycline resistant isolates were obtained from dogs that have received treatment. Erythromycin resistance or intermediate susceptibility was detected in 45.6% of isolates, most of them from dogs after treatment. For Enterococci, 48 isolates were obtained from fecal samples (25 before treatment and 23 after treatment). Before treatment, 32% of isolates were resistant at least to one antibiotic while after, this data increase up to 65%. Comparing isolates before and after treatment, a clear increase in resistance to doxycycline (12% against 21.74%) and erythromycin (20% against 39.13%) was observed. Although the present work is a preliminary research, the results encourages the development of further studies to determinate the effect of prolonged doxycycline therapy on antimicrobial resistance.

Preliminary evidence of the seroprevalence and risk factors associated with Chlamydia abortus infection in goats on the Canary Islands, Spain

The aims of this cross-sectional study were to estimate the prevalence of IgG antibodies against Chlamydia abortus, the cause of enzootic abortion, in goats and to determine its associated risk factors on the Canary Islands. A total of 325 goats from 11 non-vaccinated herds were sampled and assessed using a commercial ELISA kit. Related data were also obtained for further statistical analysis and associated risk factors to seropositive flocks. For comparison, abortion rates between the vaccinated and non-vaccinated herds were compared. The overall seroprevalence of the unvaccinated herds was 33%, which can be considered as high when compared to other European regions. Associated risk factors such as herd size, management system, diet, and manure removal frequency were found statistically significant. However, no significant differences were found in the abortion rates between vaccinated and non-vaccinated flocks, indicating that other microorganisms could also cause abortions in goats on the region. Despite this, the seroprevalence of C. abortus is relatively high in this limited survey of goat herds and may pose a threat to both human and animals on the Canary Islands.