Showing papers by "Daisy Vanrompay published in 2014"

Emerging Chlamydia psittaci infections in chickens and examination of transmission to humans

Abstract: Chlamydia psittaci and atypical Chlamydiaceae infections are (re)-emerging in chickens. We therefore examined the prevalence of C. psittaci, atypical Chlamydiaceae and their zoonotic transmission on 19 Belgian chicken farms. Atypical Chlamydiaceae were not detected in chickens but 18 out of 19 farms were positive for C. psittaci by culture and PCR. C. psittaci ompA genotypes A and D were discovered. None of the examined humans (n = 31) was infected with atypical Chlamydiaceae, but 29 (93.5%) of them were positive for C. psittaci by culture and PCR. Genotypes A, D and a mixed infection with genotypes C and D were found. Humans (n = 2) working at the C. psittaci-negative farm never had respiratory complaints, while 25 out of 29 positive farmers (86.2%) reported yearly medical complaints potentially related to psittacosis. Four of them currently experienced respiratory disease and one of them was being treated with antibiotics. Four farmers (12.5%) mentioned that they had pneumonia after starting to keep chickens. Occupational physicians should be aware of emerging Chlamydiaceae infections in chickens.

Evaluation of the presence and zoonotic transmission of Chlamydia suis in a pig slaughterhouse.

Abstract: Background: A significant number of studies on pig farms and wild boars worldwide, demonstrate the endemic presence of Chlamydia suis in pigs However, the zoonotic potential of this pathogen, phylogenetically closely related to Chlamydia trachomatis, is still uninvestigated Therefore, this study aims to examine the zoonotic transmission in a Belgian pig abattoir Methods: Presence of Chlamydia suis in pigs, contact surfaces, air and employees was assessed using a Chlamydia suis specific real-time PCR and culture Furthermore, Chlamydia suis isolates were tested for the presence of the tet(C) gene Results: Chlamydia suis bacteria could be demonstrated in samples from pigs, the air and contact surfaces Moreover, eye swabs of two employees were positive for Chlamydia suis by both PCR and culture The tet(C) gene was absent in both human Chlamydia suis isolates and no clinical signs were reported

Development and validation of a real-time PCR for Chlamydia suis diagnosis in swine and humans.

Abstract: Pigs are the natural host for Chlamydia suis, a pathogen which is phylogenetically highly related to the human pathogen C. trachomatis. Chlamydia suis infections are generally treated with tetracyclines. In 1998, tetracyline resistant C. suis strains emerged on U.S. pig farms and they are currently present in the Belgian, Cypriote, German, Israeli, Italian and Swiss pig industry. Infections with tetracycline resistant C. suis strains are mainly associated with severe reproductive failure leading to marked economical loss. We developed a sensitive and specific TaqMan probe-based C. suis real-time PCR for examining clinical samples of both pigs and humans. The analytical sensitivity of the real-time PCR is 10 rDNA copies/reaction without cross-amplifying DNA of other Chlamydia species. The PCR was successfully validated using conjunctival, pharyngeal and stool samples of slaughterhouse employees, as well as porcine samples from two farms with evidence of reproductive failure and one farm without clinical disease. Chlamydia suis was only detected in diseased pigs and in the eyes of humans. Positive humans had no clinical complaints. PCR results were confirmed by culture in McCoy cells. In addition, Chlamydia suis isolates were also examined by the tet(C) PCR, designed for demonstrating the tetracycline resistance gene tet(C). The tet(C) gene was only present in porcine C. suis isolates.

Zoonotic infection with Chlamydia psittaci at an avian refuge centre

Abstract: This paper reports the zoonotic transmission of Chlamydia psittaci at a wild bird refuge centre resulting in the infection of members of the staff. Pharyngeal swabs were culture positive in 26% (11/42) of the sampled birds, and molecular characterisation of isolates revealed genotypes A, B, D, and E/B. The finding reflects multiple distinct infections and highlights the endemic nature of this pathogen in avian wildlife. Two clinically normal birds being prepared for release were found to be excreting C. psittaci genotype B or E/B and viable genotype B was detected in pharyngeal swabs from 30% (3/10) of the human workers tested. The findings suggest there should be enhanced surveillance and control measures in place in bird rehabilitation centres in order to minimise the risk of both zoonoses and of re-introduction of infection back into wildlife populations.

The immune response against Chlamydia suis genital tract infection partially protects against re-infection

Abstract: The aim of the present study was to reveal the characteristic features of genital Chlamydia suis infection and re-infection in female pigs by studying the immune response, pathological changes, replication of chlamydial bacteria in the genital tract and excretion of viable bacteria. Pigs were intravaginally infected and re-infected with C. suis strain S45, the type strain of this species. We demonstrated that S45 is pathogenic for the female urogenital tract. Chlamydia replication occurred throughout the urogenital tract, causing inflammation and pathology. Furthermore, genital infection elicited both cellular and humoral immune responses. Compared to the primo-infection of pigs with C. suis, re-infection was characterized by less severe macroscopic lesions and less chlamydial elementary bodies and inclusions in the urogenital tract. This indicates the development of a certain level of protection following the initial infection. Protective immunity against re-infection coincided with higher Chlamydia-specific IgG and IgA antibody titers in sera and vaginal secretions, higher proliferative responses of peripheral blood mononuclear cells (PBMC), higher percentages of blood B lymphocytes, monocytes and CD8+ T cells and upregulated production of IFN-γ and IL-10 by PBMC.

Prevalence of Chlamydia abortus in Belgian ruminants

Abstract: Chlamydia (C.) abortus enzootic abortion still remains the most common cause of reproductive failure in sheep-breeding countries all over the world. Chlamydia abortus in cattle is predominantly associated with genital tract disease and mastitis. In this study, Belgian sheep (n=958), goats (n=48) and cattle (n=1849) were examined, using the ID Screen (TM) Chlamydia abortus indirect multi-species antibody ELISA. In the sheep, the highest prevalence rate was found in Limburg (4.05%). The animals of Antwerp, Brabant and Liege tested negative. The prevalence in the remaining five regions was low (0.24% to 2.74%). Of the nine goat herds, only one herd in Luxembourg was seropositive. In cattle, the highest prevalence rate was found in Walloon Brabant (4.23%). The animals of Limburg and Namur tested negative. The prevalence rate in the remaining seven regions ranged between 0.39% and 4.02%.

Detection of Chlamydia psittaci in Belgian cattle with signs of respiratory disease and milk drop syndrome

Abstract: THE term ‘milk drop syndrome’ is commonly used to refer to a sudden drop in milk yield in dairy cattle that may or may not be showing signs of other disease (Gunning and others 1999). According to Radostits and others (2007), milk drop syndrome is a herd syndrome in which the milk yield falls precipitately without any clear clinical evidence of disease or deprivation of food or water. Leptospirosis (caused by Leptospira Hardjo), heat stress and summer fescue toxicosis are among the more common causes (Radostits and others 2007). In recent years, multiple outbreaks of milk drop syndrome with fever have been reported in dairy cattle in several European countries (Crawshaw and others 2008, Guyot and others 2011). Bovine viral diarrhoea virus (BVDV) (Moerman and others 1994), Leptospira Hardjo (Pearson and others 1980), Anaplasma phagocytophilum (De Schutter and others 2011, Guyot and others 2011) and Schmallenberg virus (Veldhuis and others 2013) have been identified in several of these case herds. A potential role of influenza A virus has also been suggested (Brown and others 1998, Gunning and others 1999, Crawshaw and others 2008). Within the context of the Flemish cattle health monitoring programme (Veepeiler Rund, Belgium), a substantial number of herds recently affected with milk drop syndrome remained undiagnosed after being tested for all of the aforementioned pathogens. Additionally, respiratory symptoms were frequently mentioned as clinical signs on these farms. Since Chlamydia psittaci has recently been identified as being involved in reproductive disorders and airway inflammation in calves (Reinhold and others 2011, Ostermann and others 2013), this short communication aims to report on clinical and environmental findings in seven dairy herds with milk drop syndrome with respiratory symptoms where C. psittaci was detected in bronchoalveolar lavage (BAL) samples from diseased cows. Between June 2011 …

Chlamydial biology and its associated virulence blockers

Abstract: Chlamydiales are obligate intracellular parasites of eukaryotic cells. They can be distinguished from other Gram-negative bacteria through their characteristic developmental cycle, in addition to special biochemical and physical adaptations to subvert the eukaryotic host cell. The host spectrum includes humans and other mammals, fish, birds, reptiles, insects and even amoeba, causing a plethora of diseases. The first part of this review focuses on the specific chlamydial infection biology and metabolism. As resistance to classical antibiotics is emerging among Chlamydiae as well, the second part elaborates on specific compounds and tools to block chlamydial virulence traits, such as adhesion and internalization, Type III secretion and modulation of gene expression.