Direct detection of Ehrlichia canis by PCR in the conjuncti- va of a dog with bilateral anterior uveitis

The following report describes the direct detection of Ehrlichia canis by real-time PCR in the conjunctiva of a 1-year-old female Maltese dog. After being imported from Brazil, the dog was presented because of anorex- ia, dehydration, fever and palpable mandibular lymph nodes. A few days later, the dog developed bilateral blepharospasm, photophobia and anterior uveitis. Monocytic ehrlichiosis was diagnosed by a positive PCR result and the detection of IgM and IgG anti- bodies. Because of the massive uveitis a conjunctival sample was taken with a cytobrush, which also tested positive for Ehrlichia canis DNA by real-time PCR. Only one week after starting treatment with systemic doxycycline and local anti-inflammatory and cyclo- plegic therapy the dog recovered from systemic and eye diseases. After therapy the follow-up examination revealed a full remission of clinical and hematological parameters and a negative PCR result. Der folgende Bericht beschreibt den direkten Nach- weis von Ehrlichia canis mittels Real-Time-PCR in der Bindehaut einer 1-jährigen Malteserhündin. Kurz nach dem Import aus Brasilien wurde der Hund we- gen Anorexie, Dehydration, Fieber und tastbaren Mandibularlymphknoten vorgestellt. Ein paar Tage später entwickelte der Hund bilateralen Blepharospas- mus, Photophobie und Uveitis anterior. Die Diagnose «monozytären Ehrlichiose» wurde durch eine positive PCR und den Nachweis von IgM-und IgG-Antikör- pern gestellt. Aufgrund der massiven Uveitis wurde ein Cytobrush aus der Konjunktiva entnommen und ebenfalls mittels Real-Time-PCR positiv auf Ehrlichia canis-DNA getestet. Nur eine Woche nach Thera- piebeginn mit Doxycyclin, entzündungshemmen- den Präparaten und Zykloplegika verschwanden alle klinischen Symptome. Eine Verlaufskontrolle nach Therapieende ergab eine vollständige Remission der klinischen und hämatologischen Parameter und ein negatives PCR-Ergebnis. Keywords: Ehrlichia canis, cytobrush, real-time PCR, conjunctiva, uveiti

Die feline Leukämievirus-Infektion: Bedeutung und aktuelle Situation in der Schweiz

Feline leukemia virus (FeLV) leads to fatal disease in cats with progressive infection. The aim of this study was to determine the importance of FeLV infection in Switzerland and make a comparison with previous studies. Of 881 blood samples taken from cats living in Switzerland (minimum of 20 samples per Canton), 47 samples were provirus-positive (5.3%; 95% confidence interval (CI) 3.9-7.0%) and 18 samples were antigen-positive (2%; 95% CI 1.2-3.2%). Together with data previously collected in similar studies, these findings demonstrated a decrease in prevalence between 1997 and 2003 followed by a relative constant low prevalence thereafter. Young cats (=2 years) were more frequently infected than older cats, but FeLV-positive cats were up to 15 (antigen-positive) and 19 (provirus-positive) years old. Sexually intact cats were more frequently viremic than neutered cats; purebred cats were somewhat less frequently FeLV-positive than non-purebred cats. In a second study, in which 300 saliva samples were analyzed, samples from 5 cats were FeLV-RNA positive (1.7%; 95% CI, 0.5-3.8%), although one young feral cat had been falsely assumed to be FeLV-negative based on a point-of-care test. Of the 300 cats, only 50% were FeLV tested or vaccinated, although 90% of the cats were at risk of exposure to FeLV. Testing and vaccination of all cats with exposure risk may help further decrease the prevalence of FeLV infection. Moreover, characteristics of FeLV tests should be considered, such as the risk of false negative results in the early phase of infection when performing antigen testing

[Feline leukemia virus infection: importance and current situation in Switzerland].

Feline leukemia virus (FeLV) leads to fatal disease in cats with progressive infection. The aim of this study was to determine the importance of FeLV infection in Switzerland and make a comparison with previous studies. Of 881 blood samples taken from cats living in Switzerland (minimum of 20 samples per Canton), 47 samples were provirus-positive (5.3%; 95% confidence interval (CI) 3.9-7.0%) and 18 samples were antigen-positive (2%; 95% CI 1.2-3.2%). Together with data previously collected in similar studies, these findings demonstrated a decrease in prevalence between 1997 and 2003 followed by a relative constant low prevalence thereafter. Young cats (=2 years) were more frequently infected than older cats, but FeLV-positive cats were up to 15 (antigen-positive) and 19 (provirus-positive) years old. Sexually intact cats were more frequently viremic than neutered cats; purebred cats were somewhat less frequently FeLV-positive than non-purebred cats. In a second study, in which 300 saliva samples were analyzed, samples from 5 cats were FeLV-RNA positive (1.7%; 95% CI, 0.5-3.8%), although one young feral cat had been falsely assumed to be FeLV-negative based on a point-of-care test. Of the 300 cats, only 50% were FeLV tested or vaccinated, although 90% of the cats were at risk of exposure to FeLV. Testing and vaccination of all cats with exposure risk may help further decrease the prevalence of FeLV infection. Moreover, characteristics of FeLV tests should be considered, such as the risk of false negative results in the early phase of infection when performing antigen testing

Analysis of the Population Structure of Anaplasma Phagocytophilum Using Multilocus Sequence Typing

Anaplasma phagocytophilum is a Gram-negative obligate intracellular bacterium that replicates in neutrophils. It is transmitted via tick-bite and causes febrile disease in humans and animals. Human granulocytic anaplasmosis is regarded as an emerging infectious disease in North America, Europe and Asia. However, although increasingly detected, it is still rare in Europe. Clinically apparent A. phagocytophilum infections in animals are mainly found in horses, dogs, cats, sheep and cattle. Evidence from cross-infection experiments that A. phagocytophilum isolates of distinct host origin are not uniformly infectious for heterologous hosts has led to several approaches of molecular strain characterization. Unfortunately, the results of these studies are not always easily comparable, because different gene regions and fragment lengths were investigated. Multilocus sequence typing is a widely accepted method for molecular characterization of bacteria. We here provide for the first time a universal typing method that is easily transferable between different laboratories. We validated our approach on an unprecedented large data set of almost 400 A. phagocytophilum strains from humans and animals mostly from Europe. The typability was 74% (284/383). One major clonal complex containing 177 strains was detected. However, 54% (49/90) of the sequence types were not part of a clonal complex indicating that the population structure of A. phagocytophilum is probably semiclonal. All strains from humans, dogs and horses from Europe belonged to the same clonal complex. As canine and equine granulocytic anaplasmosis occurs frequently in Europe, human granulocytic anaplasmosis is likely to be underdiagnosed in Europe. Further, wild boars and hedgehogs may serve as reservoir hosts of the disease in humans and domestic animals in Europe, because their strains belonged to the same clonal complex. In contrast, as they were only distantly related, roe deer, voles and shrews are unlikely to harbor A. phagocytophilum strains infectious for humans, domestic or farm animals

Analysis of the population structure of Anaplasma phagocytophilum using multilocus sequence typing.

Anaplasma phagocytophilum is a Gram-negative obligate intracellular bacterium that replicates in neutrophils. It is transmitted via tick-bite and causes febrile disease in humans and animals. Human granulocytic anaplasmosis is regarded as an emerging infectious disease in North America, Europe and Asia. However, although increasingly detected, it is still rare in Europe. Clinically apparent A. phagocytophilum infections in animals are mainly found in horses, dogs, cats, sheep and cattle. Evidence from cross-infection experiments that A. phagocytophilum isolates of distinct host origin are not uniformly infectious for heterologous hosts has led to several approaches of molecular strain characterization. Unfortunately, the results of these studies are not always easily comparable, because different gene regions and fragment lengths were investigated. Multilocus sequence typing is a widely accepted method for molecular characterization of bacteria. We here provide for the first time a universal typing method that is easily transferable between different laboratories. We validated our approach on an unprecedented large data set of almost 400 A. phagocytophilum strains from humans and animals mostly from Europe. The typability was 74% (284/383). One major clonal complex containing 177 strains was detected. However, 54% (49/90) of the sequence types were not part of a clonal complex indicating that the population structure of A. phagocytophilum is probably semiclonal. All strains from humans, dogs and horses from Europe belonged to the same clonal complex. As canine and equine granulocytic anaplasmosis occurs frequently in Europe, human granulocytic anaplasmosis is likely to be underdiagnosed in Europe. Further, wild boars and hedgehogs may serve as reservoir hosts of the disease in humans and domestic animals in Europe, because their strains belonged to the same clonal complex. In contrast, as they were only distantly related, roe deer, voles and shrews are unlikely to harbor A. phagocytophilum strains infectious for humans, domestic or farm animals

Allele frequency and number of polymorphic sites of the seven loci of the <i>A. phagocytophilum</i> MLST scheme¹ and of the partial 16S rRNA² and <i>ankA</i>³ gene sequences.

1<p>284 strains typeable by MLST were included.</p>2<p>369 strains without ambiguous nucleotides were included.</p>3<p>369 sequences without ambiguous nucleotides from 363 samples were included.</p>4<p>not applicable.</p

<i>ankA</i> gene cluster and host species of the <i>A. phagocytophilum</i> strains, in which <i>ankA</i> could be amplified (n = 386).

1<p>Prevalence of strains in the data set.</p>2<p>NT = nontypeable. In these samples sequences belonging to two different <i>ankA</i> gene clusters were found.</p>3<p>n (n) = nontypeable strains (all strains).</p>4<p>n (n) = strains belonging to the respective <i>ankA</i> gene cluster (typeable strains).</p

Tyability and discriminatory indices of MLST, 16S rRNA and <i>ankA</i> gene-based typing of <i>A. phagocytophilum</i> strains.

1<p>NT = nontypeable.</p>2<p>CI = confidence interval.</p>3<p>CC = clonal complex.</p>4<p>Concatenated allele gene cluster.</p

Clonal complexes and host species of the <i>A. phagocytophilum</i> strains typeable by MLST (n = 284).

1<p>Clonal complexes were defined by sharing identical alleles at five of the seven loci with at least one other member of the group.</p>2<p>Prevalence of strains in the data set.</p>3<p>n (n) = strains belonging to the respective clonal complex (typeable strains).</p>4<p>60 (60) dogs from Europe.</p>5<p>32 (32) humans from Europe.</p>6<p>10 (10) humans from the USA.</p>7<p>1 (1) dog from the USA.</p