Occurrence and Characteristics of Escherichia albertii in Wild Birds and Poultry Flocks in Switzerland

Escherichia albertii, a zoonotic pathogen, has sporadically been associated with infectious diarrhea in humans. Poultry and wild birds are considered potential reservoirs. We assessed the occurrence of E. albertii in 280 fecal samples from wild birds (n = 130) and pooled fecal samples collected at slaughterhouse level from poultry flocks (n = 150) in Switzerland. Using an E. albertii-specific PCR targeting the Eacdt gene, 23.8% (31/130) of the samples from wild birds, but not from the pooled poultry fecal samples, tested positive for Eacdt. The positive samples originated from 11 bird species belonging to eight families. Strain isolation was attempted on the PCR-positive samples by subculturing the broth cultures onto xylose–MacConkey plates. Isolation was possible on 12 of the 31 Eacdt-PCR-positive samples. Whole-genome sequencing revealed that the strains belonged to nine distinct sequence types, with ST13420 and ST5967 being represented by two and three isolates, respectively. All strains harbored the eae gene, while two strains were also positive for stx2f. Our study thus shows that E. albertii is present in the Swiss wild bird population, which can potentially act as a source of this pathogen to humans, other animals, and the environment

Screening of Healthy Feral Pigeons (Columba livia domestica) in the City of Zurich Reveals Continuous Circulation of Pigeon Paramyxovirus-1 and a Serious Threat of Transmission to Domestic Poultry

Pigeon paramyxovirus-1 (PPMV-1) is predominantly isolated from pigeons or doves and forms a separate group of viral strains within Avian Orthoavulavirus-1, the causative agent of Newcastle disease in poultry. Since the introduction of PPMV-1 into Europe in 1981, these strains have rapidly spread all over Europe, and are nowadays considered to be enzootic in feral and hobby pigeons (Columba livia domestica). Infections with PPMV-1 can range from asymptomatic to fatal. To assess whether PPMV-1 continuously circulates in healthy feral pigeons, 396 tissue samples of pigeons from the city of Zurich were tested by reverse transcriptase real-time PCR over the period of one year. PPMV-1-RNA was detected in 41 feral pigeons (10.35%), determined as the dominant European genotype VI.2.1.1.2.2. In 38 of the 41 pigeons where organ samples tested positive, PPMV-1-RNA was also detected in either choana or cloaca swabs. There were no significant differences in positivity rates between seasons, age, and sex. The current study shows that feral pigeons without clinical signs of disease can harbour and most likely excrete PPMV-1. Spill-over into free-range holdings of chickens are therefore possible, as observed in a recent outbreak of Newcastle disease in laying hens due to PPMV-1 genotype VI.2.1.1.2.2. in the canton of Zurich in January 2022

Screening of Healthy Feral Pigeons (Columba livia domestica) in the City of Zurich Reveals Continuous Circulation of Pigeon Paramyxovirus-1 and a Serious Threat of Transmission to Domestic Poultry.

Pigeon paramyxovirus-1 (PPMV-1) is predominantly isolated from pigeons or doves and forms a separate group of viral strains within Avian Orthoavulavirus-1, the causative agent of Newcastle disease in poultry. Since the introduction of PPMV-1 into Europe in 1981, these strains have rapidly spread all over Europe, and are nowadays considered to be enzootic in feral and hobby pigeons (Columba livia domestica). Infections with PPMV-1 can range from asymptomatic to fatal. To assess whether PPMV-1 continuously circulates in healthy feral pigeons, 396 tissue samples of pigeons from the city of Zurich were tested by reverse transcriptase real-time PCR over the period of one year. PPMV-1-RNA was detected in 41 feral pigeons (10.35%), determined as the dominant European genotype VI.2.1.1.2.2. In 38 of the 41 pigeons where organ samples tested positive, PPMV-1-RNA was also detected in either choana or cloaca swabs. There were no significant differences in positivity rates between seasons, age, and sex. The current study shows that feral pigeons without clinical signs of disease can harbour and most likely excrete PPMV-1. Spill-over into free-range holdings of chickens are therefore possible, as observed in a recent outbreak of Newcastle disease in laying hens due to PPMV-1 genotype VI.2.1.1.2.2. in the canton of Zurich in January 2022

On the reproductive biology of the Fossa (Cryptoprocta ferox)

Die Fossa (Cryptoprocta ferox Bennet, 1833) gehört zu der Familie Herpestidae und ist das größte endemische Raubtier Madagaskars. Als einziger natürlicher Feind der großen Lemurenarten spielt sie eine potentiell wichtige Rolle im Räuber-Beute System der Insel. Seit 2002 wird sie auf der roten Liste der bedrohten Tierarten geführt. Die Fossa ist ein monöstrischer Einzelgänger mit einer kurzen Paarungszeit im Frühjahr. In der vorliegenden Studie sollte die europäische Zoopopulation durch reproduktionsbiologische Parameter beschrieben, saison- und geschlechtsspezifische Unterschiede erfasst und der reproduktive Gesundheitsstatus erhoben werden. Hierzu wurden über den Zeitraum von zwei Jahren 16 männliche und 15 weibliche Fossas aus zehn europäischen Zoos, und somit über 50% des europäischen Zoobestandes, meist zu beiden Saisons - Paarungszeit (PZ) und Nicht-Paarungszeit (NPZ) - untersucht. Die Körpermaße der Fossa wurden erfasst und der Penis detailliert beschrieben. Kranial des Skrotums wurde eine Erhebung entdeckt, die ultrasonographisch als zweilappige, in der Haut gelegene Drüse identifiziert und angesichts ihrer Lage als Praeskrotaldrüse bezeichnet wurde. Das Hodenvolumen und die Länge des Os penis wurden vermessen und dabei festgestellt, dass beide Größen mit dem Alter zunehmen. Das weibliche Genitale wurde auf das Vorkommen von Os clitoris und Klitorisstacheln untersucht und bei Vorkommen beider Merkmale das entsprechende Tier als maskulinisiert eingestuft. Das Os clitoris wurde aufgrund seiner geringen Größe ultrasonographisch dargestellt und vermessen - die Länge nahm mit dem Alter ab. Die ultrasonographische Darstellung und Vermessung der inneren Geschlechtsorgane und -drüsen zeigten eine Tendenz zu größeren Volumina in der PZ; bei weiblichen Tieren wurde eine Follikelanbildung auf den Ovarien festgestellt. Zu den pathologischen Befunden zählten der unilaterale Kryptorchismus sowie Zysten und schlechte Ausprägung des weiblichen Genitaltrakts. Die Hormonanalysen spiegelten die ultrasonographischen Befunde wider. Bei der Kothormonanalyse zeigten die Männchen, zwei nicht-trächtige sowie das trächtige Weibchen die höchsten Konzentrationen der gemessenen Sexualhormonmetabolite (Dihydrotestosteron bzw. 5alpha-Progesteron) innerhalb der PZ. Die Werte des trächtigen Weibchens überstiegen dabei die Konzentrationen der nicht-trächtigen um ein Vielfaches und blieben bis kurz nach der Geburt auf einem deutlich erhöhten Niveau. Im Kot zweier weiterer nicht-trächtiger Weibchen wurden über den Jahresverlauf keine deutlichen Änderungen der Sexualhormonmetabolite festgestellt. Die Bluthormonanalyse wies bei Männchen höhere Testosteronwerte als bei Weibchen nach; saisonal waren diese bei Männchen in der PZ und bei Weibchen in der NPZ erhöht. Die bei Weibchen gemessenen Estrogenwerte waren in der PZ erhöht, die Progesteronwerte in der NPZ. Die spermatologische Untersuchung umfasste die Erhebung der klassischen Ejakulat-Parameter sowie die ultrastrukturelle Beschreibung der Fossa-Spermien. Es zeichnete sich eine Tendenz zu höheren Ejakulatvolumina, höherer Motilität und geringerer Spermienkonzentration in der PZ ab. Morphologisch konnten fünf Kopftypen abgegrenzt werden, welche saisonal zu unterschiedlichen prozentualen Anteilen im Ejakulat vorkamen. Im Weiteren war in der PZ eine Tendenz zu längeren Spermien festzustellen. Die Duftstoffanalyse an Fossa-Haaren zeigte saison- und geschlechtsspezifische Duftstoffmuster und es konnten einige geschlechtsspezifische Substanzen identifiziert werden.The Fossa (Cryptoprocta ferox Bennet, 1833) belongs to the family herpestidae and is the largest endemic carnivore on Madagascar. It is the only predator of large lemur species and thus plays a potential key role in the predator-prey- relationship of this island. Since 2002 the fossa is listed in the red list of endangered species. The fossa is a solitary animal with a brief breeding season in spring. The aim of the present study was to describe the European zoo population using reproductive parameters; seasonal and gender specific differences were to be detected and the reproductive health to be evaluated. Over the period of two years, 16 male and 15 female fossas of ten European zoos, and thus over 50% of the European zoo population, were assessed during both seasons: the breeding season (BS) and the non-breeding season (NBS). The body size was depicted using morphometric measurements and the morphology of the penis was described in detail. A two-lobed gland was detected in the skin cranial to the scrotum and named by its location as "prescrotal gland". The testical volume and the length of the Os penis were measured; the size of both structures increased with the age of the animal. The female genitals were inspected for the existence of an Os clitoris and clitoridal spikes; animals exhibiting both traits were classified as masculinised. Due to its small size, the Os clitoris was visualised and measured using ultrasonographic imaging: the length of the Os clitoris decreased with the age of the animal. The ultrasonographic analysis of the internal reproductive organs and sexual glands showed a tendency towards larger volumes during the BS; in female animals ovarian follicles were detected. The reproductive organs showed several pathologies such as unilateral cryptorchism, cysts of the female genital tract or poor development of female reproductive organs. The hormone analysis refl ects the ultrasonographical findings. The assessment of faecal steroid metabolites (dihydrotestosterone, 5alpha-progesterone) showed in males as well as in two non-pregnant and one pregnant females the highest concentrations during the BS. In the pregnant animal the concentrations exceeded the values of non-pregnant animals significantly and stayed elevated until shortly after parturition. The annual pattern of faecal steroid metabolites of the remaining two non-pregnant females did not show any significant changes in concentration. The analysis of serum testosterone showed higher values in males than in females with seasonally higher values in the BS for males and the NBS for females. The levels of estrogen were higher during BS and of progesterone during NBS - both hormones were measured in females only. The spermatological analysis included the assessment of the classical semen parameters as well as the description of the ultra structure of fossa spermatozoa. The volume of the ejaculate and the motility of the spermatozoa were increased during the BS while the sperm-concentration was decreased. The morphological analysis revealed five different sperm-head categories showing a seasonal difference in abundance. Additionally, there was a tendency towards a greater total length in spermatozoa during the BS. The analysis of volatiles in fossa hair showed seasonal and gender specific patterns and a number of gender specific substances were identified

Chlamydiaceae in wild, feral and domestic pigeons in Switzerland and insight into population dynamics by Chlamydia psittaci multilocus sequence typing

Feral pigeons, common wood pigeons and Eurasian collared doves are the most common representatives of the Columbidae family in Switzerland and are mostly present in highly populated, urban areas. Pigeons may carry various members of the obligate intracellular Chlamydiaceae family, particularly Chlamydia (C.) psittaci, a known zoonotic agent, and C. avium. The objective of the study was to identify the infection rates of common free-roaming pigeons for different Chlamydia species with the overall aim to assess the risk pigeons pose to public health. In this study, 431 pigeons (323 feral pigeons, 34 domestic pigeons, 39 Eurasian collared doves, 35 common wood pigeons) from several geographic locations in Switzerland were investigated for the presence of Chlamydiaceae. Samples consisted of pooled choanal-cloacal swabs (n = 174), liver samples (n = 52), and paired swab and liver samples from 205 pigeons (n = 410). All 636 samples were screened using a Chlamydiaceae family-specific 23S rRNA real-time PCR (qPCR). Subsequent species identification was performed by DNA-microarray assay, sequencing of a 16S rRNA gene fragment and a C. psittaci specific qPCR. In total, 73 of the 431 pigeons tested positive for Chlamydiaceae, of which 68 were positive for C. psittaci, four were C. avium-positive and one pigeon was co-infected with C. avium and C. psittaci. The highest infection rates were detected in feral (64/323) and domestic pigeons (5/34). Common wood pigeons (2/35) and Eurasian collared doves (2/39) revealed lower infection rates. Additionally, multilocus sequence typing of twelve selected C. psittaci-positive samples revealed closely related sequence types (ST) between and within different Swiss cities. Furthermore, liver and corresponding swab samples from the same bird were colonized by the same ST. Considering the high infection rates of C. psittaci in domestic and feral pigeons, close or frequent contact to these birds poses a human health risk

Occurrence of Chlamydiaceae in Raptors and Crows in Switzerland

Bacteria of the family Chlamydiaceae are globally disseminated and able to infect many bird species. So far, 11 species of Chlamydia have been detected in wild birds, and several studies found chlamydial strains classified as genetically intermediate between Chlamydia (C.) psittaci and C.abortus. Recently, a group of these intermediate strains was shown to form a separate species, i.e., C.buteonis. In the present study, 1128 samples from 341 raptors of 16 bird species and 253 corvids representing six species were examined using a stepwise diagnostic approach. Chlamydiaceae DNA was detected in 23.7% of the corvids and 5.9% of the raptors. In corvids, the most frequently detected Chlamydia species was C.psittaci of outer membrane protein A (ompA) genotype 1V, which is known to have a host preference for corvids. The most frequently detected ompA genotype in raptors was M56. Furthermore, one of the raptors harbored C.psittaci 1V, and two others carried genotype A. C.buteonis was not detected in the bird population investigated, so it remains unknown whether this species occurs in Switzerland. The infection rate of Chlamydiaceae in corvids was high compared to rates reported in other wild bird species, but neither Chlamydiaceae-positive corvids nor raptors showed overt signs of disease. Since the Chlamydiaceae of both, raptors and crows were identified as C.psittaci and all C.psittaci genotypes are considered to be zoonotic, it can be suggested that raptors and crows pose a potential hazard to the health of their handlers

Inconspicuous post-mortem findings in rabbits from Switzerland naturally ­infected with Rabbit Haemorrhagic ­Disease Virus 2

Rabbit Haemorrhagic Disease Virus 2 (RHDV-2) emerged in France in 2010. In Switzerland, RHDV-2 was first identified in 2015 and apparently has almost replaced the classical Rabbit Haemorrhagic Disease Virus (RHDV) by now. Like RHDV, RHDV-2 causes a viral hepatitis with a peracute course and an increased mortality rate within the rabbitry. RHDV infection causes consistent gross pathological findings, especially in the liver and respiratory tract. Reports about gross pathology for animals naturally infected with RHDV-2 is scarce. The present study analysed the anamnesis and necropsy reports of 35 rabbits examined during routine diagnostics between March 2015 and May 2017. A reverse transcriptase real-time polymerase chain reaction (RT-qPCR) specific for RHDV-2 and RHDV proved a total of 25 animals to be positive for RHDV-2, while none was positive for RHDV. Additionally, histological examinations were performed on liver, lung, and kidney of 18 rabbits that had tested positive by RHDV-2 RT-qPCR. The anamnestic report more often stated an increased mortality rate in RHDV-2 positive (16/18, 89 %) compared to RHDV-2 negative rabbits (3/9, 33 %). Gross pathology did not reveal any pathognomonic changes in RHDV-2 positive animals. Histologically, the liver showed the most severe lesions followed by lung and kidney. Animals positive for RHDV-2 frequently showed signs of gastro-intestinal disease (n = 5) and/or septicaemia (n = 6) masking possible indicators of an RHDV-2 infection, such as the rather unspecific findings of an enlarged spleen or an enlarged, friable, tan-coloured liver. The authors want to raise awareness among clinicians and pathologists that in case of sudden death in commercial or pet rabbits, RHDV-2 needs to be considered as differential diagnosis and should be confirmed by laboratory diagnosis

Antimicrobial resistant and extended‐spectrum β‐lactamase producing Escherichia coli in common wild bird species in Switzerland

A total of 294 fecal swabs from 294 wild birds in Switzerland were cultivated for antimicrobial resistant (AMR) Escherichia coli. Samples were also subcultivated to detect E. coli with extended-spectrum β-lactamases (ESBL), carbapenemases, and plasmid-mediated aminoglycoside or colistin resistance, respectively. Samples from 17 (5.8%) of the birds contained 19 AMR E. coli, whereof 26.3% were multidrug resistant. Five (1.7%) ESBL-producing E. coli were detected. The isolates harbored blaCTX-M-1 (two isolated from carrion crows and from one great spotted woodpecker, respectively), blaCTX-M-15 (originating from a grey heron), blaCTX-M-55 (from a carrion crow), and blaCTX-M-65 (from a common blackbird). Phylogenetic analysis assigned three isolates to commensal phylogroups A and B1, one to extraintestinal pathogenic group B2, and one to phylogroup F. Multilocus sequence typing identified sequence types (STs) that have been found previously in ESBL E. coli in wild birds (ST58, ST205, ST540). One isolate harboring blaCTX-M-55 was assigned to the recently emerged fluoroquinolone-resistant, extraintestinal pathogenic E. coli clone ST1193. Wild birds have the potential to disperse AMR, including clinically important resistance genes, from anthropogenic-influenced habitats to diverse areas, including vulnerable natural environments such as surface waters or mountain regions

Survey on Chlamydiaceae in cloacal swabs from Swiss turkeys demonstrates absence of Chlamydia psittaci and low occurrence of Chlamydia gallinacean

In Switzerland, domestic turkey meat is a niche product. Turkeys are fattened on mixed family-based farms scattered across the country, with most providing access to an uncovered outdoor pasture for the birds. Swiss fattening turkeys may therefore get infected with Chlamydiaceae via wild birds or their faeces, potentially shedding these bacteria at a later stage. The aim of the present study was to acquire baseline data about the shedding of Chlamydiaceae in clinically unremarkable Swiss fattening turkeys at slaughter, potentially exposing slaughterhouse workers to infection. In this large-scale study, 1008 cloacal swabs of Swiss turkeys out of 53 flocks from 28 different grow-out farms with uncovered outdoor pasture were collected over the course of 14 months and examined for the occurrence of Chlamydiaceae by a family-specific 23S-rRNA real-time PCR. Positive samples were further analyzed by Chlamydia psittaci (C. psittaci)-specific real-time PCR and the Arraymate DNA Microarray for species identification. All samples were negative for C. psittaci, but seven swabs out of one flock were tested positive for Chlamydia gallinacea (0.7%). Although turkeys with access to pasture may have contact with Chlamydiaceae-harbouring wild birds or their faeces, the infection rate in Swiss turkeys was shown to be low