Chlamydophila psittaci in free-living Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil

Chlamydophila psittaci (C. psittaci) infection was evaluated in 77 free-living nestlings of Blue-fronted Amazon parrots (Amazona aestiva) and Hyacinth macaws (Anodorhynchus hyacinthinus) in the Pantanal of Mato Grosso do Sul, Brazil. Tracheal and cloacal swab samples from 32 wild parrot and 45 macaw nestlings were submitted to semi-nested PCR, while serum samples were submitted to complement fixation test (CFT). Although all 32 Amazon parrot serum samples were negative by CFT, cloacal swabs from two birds were positive for Chlamydophila DNA by semi-nested PCR (6.3%); these positive birds were 32 and 45 days old. In macaws, tracheal and cloacal swabs were positive in 8.9% and 26.7% of the samples, respectively. Complement-fixing antibodies were detected in 4.8% of the macaw nestlings; macaw nestlings with positive findings were between 33 and 88 days old. These results indicate widespread dissemination of this pathogen in the two evaluated psittacine populations. No birds had clinical signs suggestive of chlamydiosis. To the best of our knowledge, this is the first report on C. psittaci in free-living Blue-fronted Amazon parrots and Hyacinth macaws in Brazil.     

Chlamydophila psittaci DNA detection in the faeces of cage birds

In this study, we investigated the shedding of Chlamydophila psittaci in faecal samples from cage birds using PCR testing. A total of 47 faeces samples were collected from four different aviaries. Main symptoms determined after clinical investigation and owner histories of the birds showed that the birds had respiratory system problems changing from mild to severe. They also showed conjunctivitis, diarrhoea or no symptoms at all. DNA extractions from faeces were performed with the QIAamp DNA Stool Mini Kit. Following PCR with Cp. psittaci specific primers, 43 (91.5%) samples were determined to harbour-specific DNA. Only one bird from each aviary was found to be negative by PCR. As all the samples from birds showing clinical signs were PCR positive, these signs could be correlated to psittacosis in these birds. Cp. psittaci shedding in faeces was detected in all the aviaries. After restriction analysis of PCR amplicons with AluI enzyme, all the isolates showed the same RFLP (Restriction Fragment Length Polymorphism) patterns with the control Cp. psittaci DNA. PCR following QIAamp DNA stool mini kit extraction of faecal samples was found to be a rapid, specific, sensitive, reproducible test, which did not need additional nested PCR of samples.     

Giardia infection in budgerigars

Budgerigars ( Melopsittacus undulatus ) from two different breeding colonies were found to have Giardia infection. Light microscopy, scanning electron microscopy and in-vitro and in-vivo studies confirmed the species was G psittaci . Chicks were clinically affected and showed signs of retarded growth, dehydration and diarrhoea. The faeces of adult birds treated with metronidazole in drinking water were negative for Giardia 5 days after treatment. Megabacteria were also found in adult birds but were not treated. This study extends the known host range for Giardia in Australia to include budgerigars.     

The clinical efficacy of topical and systemic therapy for the treatment of feline ocular chlamydiosis

Twenty-four specific-pathogen-free-derived cats aged four to 11 months were challenged by ocular application of a field isolate of Chlamydia psittaci to evaluate the effect of topical and systemic therapy on the course of disease. The cats were monitored for 35 days post-challenge, with severity of clinical signs being measured using a scoring system, and ocular shedding of the organism monitored by culture of conjunctival swabs. All cats developed active C psittaci infection, and after 7 days the cats were randomly assigned to one of four treatment groups: Group P (placebo) was given twice-daily ophthalmic tear-replacement ointment; group F was given twice-daily topical 1% fusidic acid ophthalmic viscous drops; group C was given twice-daily topical 1% chlortetracycline ophthalmic ointment; and group D was given doxycycline at 10 mg/kg daily per os in addition to twice-daily topical 1% fusidic acid ophthalmic ointment. Within 24 h of commencement of therapy, group D had significantly lower median clinical scores than group P, and with the exception of day 16, this trend was maintained throughout the observation period. Median clinical scores of cats in group F were not appreciably different to those in group P, whereas the median scores of cats in group C generally fell between those of groups P and D. The median duration of C psittaci shedding was 10 and 15 days for groups D and C respectively, but four of the six cats in groups F and P were still shedding organisms at the end of the study (day 35). In this study, systemic therapy with doxycycline proved superior to topical therapy in the treatment of feline chlamydiosis.     

Effectiveness of doxycycline in the prevention of an experimental infection with Actinobacillus pleuropneumoniae in pigs

The effectiveness of medication with doxycycline in feed in the control of pleuropneumonia in pigs was tested using an Actinobacillus pleuropneumoniae serotype 1 aerosol challenge model. Two groups of 10 animals were used for the challenge, a 'medicated group' and an 'unmedicated group'. A third group of four animals was used as a 'control group'. Pigs from the medicated group were provided with feed containing 250 p.p.m. doxycycline (HIPRAMIX/DOXI) for 8 consecutive days and were challenged on the fifth day of treatment. No clinical signs were observed in pigs from the 'control group'. Four animals from the 'unmedicated group' died within the first 48 h after challenge with clinical and lesional evidence of an acute form of pleuropneumonia. Clinical signs of animals surviving the first 48 h were progressively less severe and showed lesions similar to those described for subacute-chronic forms of the disease. However, only one animal from the 'medicated group' showed clinical signs of a chronic form of pleuropneumonia. Reisolation of A. pleuropneumoniae was more evident from lung tissues of animals fed the doxycycline-free feed (70%), coinciding with the presence of both acute and subacute lesions. However, the micro-organism could be reisolated from only one animal which belonged to the 'medicated group'. It is concluded that the treatment of pigs with 250 p.p.m. doxycycline (HIPRAMIX/DOXI) prevents disease caused by A. pleuropneumoniae.     

Evaluation of bioaerosol sampling techniques for the detection of Chlamydophila psittaci in contaminated air

Chlamydophila (C.) psittaci, a category B bioterrorism agent, causes respiratory disease in birds and psittacosis or parrot fever in man. The disease spreads aerogenically and no vaccines are available for either birds or man. Highly sensitive C. psittaci bioaerosol monitoring methods are unavailable. We evaluated: (1) dry filtration for collecting C. psittaci from contaminated air using different samplers and membrane filters, (2) impingement into different liquid collection media by use of the AGI-30 impinger and the BioSampler and (3) impaction into newly designed C. psittaci media utilizing the MAS-100 aerosol impactor. For personal bioaerosol sampling, we recommend the use of a gelatin filter in combination with the IOM inhalable dust sampler at an airflow rate of 2L/min. This allowed the detection of 10 organisms of C. psittaci by both PCR and culture. For stationary bioaerosol monitoring, sampling 1000L of air in 10min with the MAS-100 impactor and ChlamyTrap 1 impaction medium was most efficient and made it possible to detect 1 and 10 C. psittaci organisms by PCR and culture, respectively. ChlamyTrap 1 in combination with the MAS-100 impactor might also be applicable for bioaerosol monitoring of viruses.     

Infection of turkeys with Ornithobacterium rhinotracheale and Mycoplasma synoviae

Within 1 mo, two separate outbreaks of respiratory disease occurred in two flocks on the multiage market turkey farm in Slovenia. More severe dinical signs and higher mortality were observed in male birds. Ornithobacterium rhinotracheale (ORT) was isolated in pure culture from tracheas of the affected birds in both outbreaks. Commercial enzyme-linked immunosorbent assay test showed the presence of antibodies to ORT in sera of birds from both clinically affected flocks and also in two flocks of younger birds without clinical sings. Immunoblotting with ORT culture isolated during the outbreak as an antigen confirmed the presence of antibodies to ORT in sera of turkeys of all four flocks examined. In addition, three different serologic assays also detected antibodies to Mycoplasma synoviae (MS) in three out of four flocks. The concomitant infection with MS did not show an obvious effect on mortality rates nor on the antibody response against ORT. Younger birds appeared to be less susceptible to ORT pathogenicity because in those flocks the infection was subclinical.     

Epidemiological investigation of Chlamydophila psittaci in pigeons and free-living birds in Croatia

During 2003, 278 adult pigeons (Columba livia) and 54 birds of 11 other free-living species were caught in the various locations in the City of Zagreb, Croatia. Sera from 182 pigeons were tested for the presence of antibodies against Chlamydophila (C.) psittaci by ELISA test and 174 of them (95.6%) were found positive. Because of the high positivity rate in sera, cloacal swabs of 278 pigeons as well as 54 other species of free-living birds were tested for the presence of C. psittaci antigen. Fourty-four of the 278 pigeons (15.83%) were antigen positive, whereas all 54 of the wild birds were negative. Antigen-positive pigeons were euthanised and examined pathomorphologically and cytologically. Findings of specific antibodies and antigen of C. psittaci confirmed the high rate of infection among urban pigeons in the City of Zagreb, fortunately not among other free-living birds. Although the pigeon serovars of C. psittaci are considered to be of moderate pathogenicity for humans, the identification of 15.8% antigen-positive birds represents a potential source of infection to humans, especially for elderly people and immunodeficient patients, as well as for poultry in the Zagreb city area.     

Study of infection with an Iranian field-isolated H9N2 avian influenza virus in vaccinated and unvaccinated Japanese quail

In the present study, we examined the mortality rate, egg production, and clinical signs of quail experimentally infected with a field isolate of A/Chicken/Iran/339/02 (H9N2) avian influenza virus obtained from an infected commercial layer farm with severe morbidity and mortality. A total of 120 quail at 14 days old were randomly divided into four groups of vaccinated (B and C) and unvaccinated (A and D) birds. Vaccination was done on days 20 and 32, and viral inoculation of birds in groups C and D was then carried out on day 43. For evaluation of viral transmission, at 24 hr postinoculation additional unvaccinated birds were placed in direct contact with challenged birds. All the birds were evaluated for clinical signs, egg production, antibody production, viral titration in lung homogenates, and viral transmission following inoculation. All unvaccinated-challenged birds were infected and showed clinical signs, whereas the infection rate along with clinical signs of vaccinated-challenged birds reached 30%-40%. Although vaccination induced high antibody titers, reduction in food and water consumption was evident in this vaccinated-challenged group compared with the unchallenged control group. These results could indicate that inactivated vaccine did not fully prevent the infection, although it was capable of protecting birds against clinical signs and significantly decreased viral titers in lungs after intranasal challenge.     

一例朱鹮雏鸟皮下气肿的诊治

动物皮下气肿成因复杂,鸟类(禽类)的皮下气肿常见于体内气囊破裂所致。德清县珍稀动物繁育研究中心2012年首次出现了1例人工饲养的朱鹮雏鸟在15日龄时发生皮下气肿。该气肿位于右侧大腿处,内部充气,气泡内未见其他病变。根据其临床症状,推测可能是由于患雏与其他雏鸟嬉戏打斗过度的充气,或受到撞击等原因使气囊破裂。诊断为右侧腹或后胸气囊破裂,引发皮下气肿。鉴于临床上穿刺排气效果不显著,以及开创排气易引起细菌感染等因素,本病例采用了自然恢复的治疗方式,将患雏转入安静环境,避免外界干扰,加强防护,减少剧烈运动,实行隔离饲养等措施,15日后气肿变小,25日后气肿消失。该病例的诊治及病因的推测,为珍稀鸟类临床上该病的防治提供了方法。     

Long-term study of Chlamydophilosis in Slovenia

Immune reactivity for Chlamydophila (C.) psittaci in Slovenia was monitored in parrots, canaries, finches and nine species of recently captured free-living birds (house sparrows, Eurasian goldfinches, tree sparrows, chaffinches, European greenfinches, European serines, Eurasian siskins, Eurasian linnets and Eurasian bullfinches) in the period from 1991 to 2001. In subsequent years, specific IgG antibodies were found using immunofluorescence in parrots (0.7-53.6%), canaries (0.0-3.5%), finches (0.0-5.7%) and in captured free-living birds (33.3% of Eurasian goldfinches in 1994). An experimental infection with C psittaci was performed in order to study clinical signs and pathological changes in canaries and finches. The C. psittaci strain used for experimental infection was isolated from a cockatiel (Nymphicus hollandicus). Chlamydial DNA was extracted from clinical material followed by RFLP-PCR analysis. Infection of canaries and finches was confirmed in organ smears by direct immunofluorescence and a modified Gimenez staining method. In addition, serological tests of indirect immunofluorescence and complement fixation were applied. However, in spite of positive immunological reaction there were no clinical signs three weeks after infection. The present study includes results of a serological survey of persons belonging to the most important risk groups (breeders, pet shopkeepers and veterinarians). The results of microimmunofluorescence to identify the presence of specific antibodies and correlation between appearance of infection in birds and important risk groups are presented. Out of 143 persons belonging to the high-risk group we found 10 (7%) persons who were immunologically positive. Testing of two successive samples was used to demonstrate an increase in IgG and IgA titres in human sera. However, IgM, which is indicative of acute infection, could not be detected.     

Controlled study of the efficacy of clavulanic acid-potentiated amoxycillin in the treatment of Chlamydia psittaci in cats

Twenty-four specific pathogen-free cats were inoculated with 3 x 10(3) infectious units of a field isolate of Chlamydia psittaci on to the corneal surface. Seven days later they were assigned randomly to three groups of eight and treated orally for 19 days with either clavulanic acid-potentiated amoxycillin, doxycycline or a placebo. Both treated groups responded rapidly, with a marked reduction in isolation rates and clinical scores which were significantly lower than in the placebo group within two and four days, respectively. After two days the group treated with potentiated amoxycillin had a significantly lower isolation score than the group treated with doxycycline. Forty days after they were infected the clinical signs recurred in five of the eight cats treated with potentiated amoxycillin, but a four-week course of potentiated amoxycillin resulted in a complete clinical recovery with no evidence of a recurrence for six months.     

A comparative study of detecting Chlamydophila psittaci in pet birds using isolation in embryonated egg and polymerase chain reaction

This study, for the first time in Turkey, investigated the existence of Chlamydophila psittaci and determined the prevalence of its disease, chlamydiosis, in pet birds. Polymerase chain reaction (PCR) was compared with other testing methods that have been typically used in the diagnosis of C. psittaci. Fecal specimens (n =96) of avian origin were tested by PCR and two identification methods, modified Gimenez staining (mGS) and direct fluorescein-conjugated monoclonal antibody staining (FA). The identification methods were implemented by staining the yolk sacs of embryonated chicken eggs inoculated at 6 days of age and harvested between 3 and 10 days after inoculation. Fecal specimens from pet birds were randomly collected from pet shops and homes. These specimens were then used to isolate C. psittaci and to detect its specific DNA. The inocula that were prepared from fecal specimens were then inoculated into yolks of 6-day-old embryonated chicken eggs. The preparations from egg yolk sacs were examined with mGS and direct FA after three blind passages. The PCR method was used to detect specific DNA in feces. In 96 fecal specimens, 33 (34.4%) were positive with PCR, 21 (21.9%) were positive with mGS, and 29 (30.2%) were positive with FA. Among 33 positive specimens with PCR, 28 specimens were positive with FA, and 20 specimens were positive with mGS. The sensitivity and specificity were 59% and 94% between FA and mGS, and 97% and 93% between FA and PCR, respectively.     

Determination of the inhibitory concentration 50% (IC50) of four selected drugs (chlortetracycline, doxycycline, enrofloxacin and difloxacin) that reduce in vitro the multiplication of Chlamydophila psittaci

A total of 18 chlamydial isolates from various psittacine birds, one isolate from a domestic pigeon and one isolate from a Pekin duck were isolated in continuous Buffalo Green Monkey (BGM) kidney cell cultures. All 20 isolates were identified by nested multiplex polymerase chain reaction as Chlamydophila psittaci. These isolates were multiplied to high titres and subsequently tested for in vitro sensitivity against two tetracyclines (chlortetracycline and doxycycline) and two quinolones (enrofloxacin and difloxacin) at concentrations of 0.0, 0.25, 0.50, 1.00, and 10.00 microg/ml. Replication of chlamydia in BGM cell cultures is assayed on the basis of formation of intracytoplasmic inclusions that are visualized by Giménez staining. All isolates, although to variable degrees, are sensitive to all four drugs. The number of chlamydial inclusions decreases gradually over a broad range of increasing concentrations of the drugs. The variation in the number of inclusions between isolates is remarkably high for chlortetracycline less for doxycycline and minimal for both fluoroquinolones, the enrofloxacin and difloxacin. The decline in numbers of inclusions is highly dose-dependend and the observed reduction stretches over a wide range of drug dilutions. Therefore, it is proposed to calculate drug sensitivity values in terms of inhibitory concentration 50%, (IC5). Its calculation includes all tested drug dilutions instead of the hitherto more common minimal inhibitory concentration, MIC, which is based on results of serial dilution tests for cell-free growing bacteria. Using a logistic regression model for the calculation of the inhibitory concentration 50% of all 20 chlamydial isolates, the IC50 is 0.807 microg/ml for tetracycline, 0.497 microg/ml for doxycycline, 0.180 microg/ml for enrofloxacin and 0.168 microg/ml for difloxacin. Complete prevention of inclusion formation was already seen for enrofloxacin at a concentration of 1.0 microg/ml in 12 out of 20 and for difloxacin in 5 out of 20 isolates whereas more than 10 microg/mI chlortetracycline is needed in 15 out of 20 isolates and for doxycycline 9 out of 20 isolates yielded inclusions at 10 microg/ml.     

Field investigation of Mycoplasma gallisepticum infections in house finch (Carpodacus mexicanus) eggs and nestlings.

We conducted a field study to investigate the occurrence of Mycoplasma gallisepticum (MG) in eggs and nestlings from nests of house finches (Carpodacus mexicanus). Forty-three nests were located between the months of April and August 1998 and were followed with one to three sampling efforts. Vitelline membrane of fresh eggs, whole embryos, or swabs from the choanal cleft or conjunctiva of nestlings were inoculated into mycoplasma broth for MG isolation and polymerase chain reaction (PCR) testing. No isolation of MG was made from 39 eggs or 110 nestlings sampled during the study. Pooled choanal and conjunctival swab samples from two broods of nestlings, however, tested positive for MG by PCR. None of the nestlings examined showed clinical signs of conjunctivitis, and no nestling mortality could be linked to MG infection. Serologic tests from 37 older nestlings were negative for antibodies to MG. The results suggest transmission of MG is occurring between breeding adults and their dependent offspring (pseudovertical transmission). Evidence supporting transovarian transmission of MG was not found in these house finches.     

Evaluation of the prophylactic use of ovotransferrin against chlamydiosis in SPF turkeys

Chlamydophila (C.) psittaci infections are highly prevalent in turkeys and the economical and public health importance of these infections has been recognized since 1950. As there are no vaccines, antibiotic treatment (tetracylines, enrofloxacine) is often needed to allow marketing of poultry. In this study, we explored the use of ovotransferrin (ovoTF), a natural anti-microbial protein, in preventing an experimental C. psittaci infection in specific pathogen free (SPF) turkeys. Turkeys were treated with aerosolized ovoTF prior to the infection. Groups 1 and 2 received a single dose of 10 and 5 mg ovoTF per turkey, respectively. Group 3 received a daily dose of 5mg ovoTF per turkey during 12 days. Group 4 served as untreated, infected control group. Turkeys were aerosol infected using 10(6) TCID(50) of the virulent C. psittaci serovar/genotype D strain 92/1293. Birds were monitored (clinical signs, bacterial excretion) during 12 subsequent days before being necropsied. At necropsy, pathology and C. psittaci replication in various tissues was examined. A single dose of 10mg ovoTF and a repeated daily dose of 5mg ovoTF could not prevent the birds from becoming infected with C. psittaci, but they significantly reduced the outcome of the infection. A single dose of 5mg ovoTF had no influence on the outcome of the infection as compared to the non-treated infected controls. Our results demonstrate the anti-chlamydial effect of ovoTF in vivo and present a base for further research on practical applications of ovoTF on turkey farms.     

Experimental infection of highly pathogenic avian influenza virus H5N1 in black-headed gulls (Chroicocephalus ridibundus)

Historically, highly pathogenic avian influenza viruses (HPAIV) rarely resulted in infection or clinical disease in wild birds. However, since 2002, disease and mortality from natural HPAIV H5N1 infection have been observed in wild birds including gulls. We performed an experimental HPAIV H5N1 infection of black-headed gulls (Chroicocephalus ridibundus) to determine their susceptibility to infection and disease from this virus, pattern of viral shedding, clinical signs, pathological changes and viral tissue distribution. We inoculated sixteen black-headed gulls with 1 × 10⁴ median tissue culture infectious dose HPAIV H5N1 (A/turkey/Turkey/1/2005) intratracheally and intraesophageally. Birds were monitored daily until 12 days post inoculation (dpi). Oropharyngeal and cloacal swabs were collected daily to detect viral shedding. Necropsies from birds were performed at 2, 4, 5, 6, 7, and 12 dpi. Sampling from selected tissues was done for histopathology, immunohistochemical detection of viral antigen, PCR, and viral isolation. Our study shows that all inoculated birds were productively infected, developed systemic disease, and had a high morbidity and mortality rate. Virus was detected mainly in the respiratory tract on the first days after inoculation, and then concentrated more in pancreas and central nervous system from 4 dpi onwards. Birds shed infectious virus until 7 dpi from the pharynx and 6 dpi from the cloaca. We conclude that black-headed gulls are highly susceptible to disease with a high mortality rate and are thus more likely to act as sentinel species for the presence of the virus than as long-distance carriers of the virus to new geographical areas.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0084-9) contains supplementary material, which is available to authorized users.     

Infectivity and persistence of an outbreak strain of Salmonella enterica serotype Typhimurium DT160 for house sparrows (Passer domesticus) in New Zealand

AIM: To examine the infective dose, incubation period and disease progression of an isolate of Salmonella enterica serotype Typhimurium definitive type 160 (DT160) originating from a naturally-infected house sparrow (Passer domesticus) during an outbreak of the disease in New Zealand. METHODS: Thirty-six house sparrows captured from the wild and free of Salmonella spp were divided into six groups of six birds, housed individually, and inoculated orally with phosphate buffered saline (PBS) or 10(1), 10(2), 10(3), 10(5), 2 x 10(8) colony forming units (cfu) of the outbreak strain of S. Typhimurium DT160. The birds were observed for 10 days for clinical signs and/or mortality, and faecal samples were collected to determine excretion of S. Typhimurium. The birds were euthanised 11 days post-inoculation (p.i.) and a wide range of tissue samples were collected for histopathological examination, and culture and typing of Salmonella spp. Macro-restriction profiling by pulsed-field gel electrophoresis (PFGE) using XbaI was performed for the epidemiological typing of S. Typhimurium DT160 isolates. RESULTS: Mortality in house sparrows inoculated with S. Typhimurium DT160 was dose-dependent, and 2/6 birds inoculated with 10(5) cfu and all six birds inoculated with 2 x 10(8) cfu died during the study. Infected sparrows displayed few clinical signs, apart from diarrhoea and/or polyuria, fluffed plumage, and sitting on the floor of the cage. Faecal excretion of DT160 occurred briefly in two birds inoculated with 10(2) cfu and four birds inoculated with 10(3) cfu, on most days in five birds inoculated with 10(5) cfu, and continuously in six birds inoculated with 2 x 10(8) cfu. DT160 was isolated from the livers of three birds which received 10(3) cfu, five birds dosed with 10(5) cfu, and all six birds given 2 x 10(8) cfu. Following necropsy, histopathological lesions similar to those seen in the natural disease were observed in the liver or spleen of three birds which received 10(3) cfu, and all birds dosed with > or =10(5) cfu. CONCLUSION: The results indicate that an isolate of S. Typhimurium DT60 originating from house sparrows in New Zealand is pathogenic to these birds and that the response is dose dependent. The persistence and excretion of the pathogen may last for at least 10 days. This confirms that sparrows infected with DT160 could be a source of infection to humans and other in-contact animals.     

Evaluation of a recombinant enzyme-linked immunosorbent assay for detecting Chlamydophila psittaci antibodies in turkey sera

Chlamydophila psittaci (formerly Chlamydia psittaci) is one of the major pathogens associated with turkey respiratory disease. Devastating outbreaks with high mortality rates, similar to those of 1950 to 1970 in the USA occasionally occur, but respiratory signs without or with low mortality mostly characterize outbreaks now a day. Accurate diagnostic methods should be made available. The present study examined the sensitivity and specificity of a recombinant ELISA (rMOMP ELISA) for detecting Cp. psittaci major outer membrane specific antibodies in turkey sera. Test results were compared to those of immunoblotting and of a competitive ELISA (Chlamydia-psittaci-AK-EIA, R?hm Pharma, Germany) and an indirect ELISA (LPS/LGP) detecting antibodies to the lipopolysaccharide/lipoglycoprotein complex. The rMOMP ELISA was most sensitive as determined on serial dilutions of positive control sera originating from experimentally infected SPF turkeys. The competitive ELISA gave false positives since three negative controls reacted positive. For conventional sera, the sensitivities of the competitive ELISA, immunoblotting and the indirect ELISA were found to be 99.4, 93.1 and 82.2%, respectively, as compared to the rMOMP ELISA (100%). The specificities of the rMOMP ELISA, immunoblotting and the indirect ELISA were found to be 100% while the specificity of the competitive ELISA was only 2.7%. The rMOMP ELISA was chosen to compare the prevalence of chlamydiosis in 2002 with the one from 1992. In 2002, 188 on 200 (94%) turkey sera reacted positive compared to 175 on 200 (87.5%) in 1992 and like 10 years ago all examined farms were seropositive at slaughter. Interestingly, Belgian as well as French farms were seropositive.     

Effects of Mycoplasma gallisepticum on reproductive success in house finches

Long known as a pathogen of poultry, Mycoplasma gallisepticum (MG) was first detected in house finches in 1994. The disease rapidly spread throughout the eastern United States and Canada and was associated with debilitating disease and high mortality in house finches. However, in the late 1990s, the proportion of infected finches dying as a result of infection with MG decreased, and asymptomatic infection was more common among wild birds than in the past. We documented MG infections in breeding house finches and concluded that adults of both sexes transmit the infection to dependent young, probably after hatch. MG infections of breeding adults occurred late in the breeding season and were found in birds completing significantly more nests than birds that never tested positive for MG, implying that higher rates of reproduction carry a cost in the form of increased risk of infection. We found evidence of an MG-induced delay in dispersal of nestlings from their natal area and demonstrated a significant impact of infection on nestling growth.