Chlamydia gallinacea, not C. psittaci, is the endemic chlamydial species in chicken (Gallus gallus)

Abstract

To investigate the prevalence and diversity of Chlamydia spp. in domestic birds in China, oral and cloacal swabs of healthy chickens, ducks, geese and pigeons were collected nationwide from live-animal markets and examined by Chlamydia spp. 23 S rRNA gene FRET-PCR followed by high-resolution melting curve analysis and confirmatory sequencing. Overall, 26.2% of the birds (602/2,300) were positive for Chlamydia spp. and five Chlamydia spp. were identified. While occasional detection of C. suis and C. muridarum in poultry is reported here for the first time, the predominant chlamydial agent was C. gallinacea representing 63.8% of all positives (384/602) and 81.2% of positive chickens (359/442). Analysis of the C. gallinacea ompA phylogeny revealed at least 13 well segregated variants (serovars). Seven-month monitoring of C. gallinacea-infected chickens indicated that the infection was persistent. C. gallinacea-infected chickens remained without overt clinical disease, but showed body weight gains significantly reduced by 6.5–11.4% beginning in week 3 post-infection. This study indicates that C. gallinacea is the endemic chlamydial species in chickens, whereas C. psittaci dominates only in pigeons. Further studies are required to address the specific conditions under which C. gallinacea could act as an avian pathogen and possibly also a zoonotic agent.

Dissemination and genetic diversity of chlamydial agents in Polish wildfowl: Isolation and molecular characterisation of avian Chlamydia abortus strains

“…psittaci / C . abortus intermediates have never been recorded in domestic waterfowl which was certainly subjected to more intensive chlamydial screenings in the past [13, 42] than wild populations. This could be ascribed to the predominance of the classical goose- and duck-specific C .…”

“…suis and C . muridarum [11–13], can also be harboured by birds as well as the recently described avian species C . gallinacea and C .…”

Molecular detection of colistin resistance genes (mcr-1, mcr-2 and mcr-3) in nasal/oropharyngeal and anal/cloacal swabs from pigs and poultry

“…In addition, 1,690 cloacal and 1,628 oropharyngeal samples from poultry (n = 1,836) at 38 live-bird markets in 24 different provinces in China were collected in 2014 (Fig. 1) 35 . Both of the swabs from the initial and terminal alimentary systems were collected from 98 pigs and 1,507 poultry in this study.…”

Newly identified colistin resistance genes, mcr-4 and mcr-5, from upper and lower alimentary tract of pigs and poultry in China

“…In addition, oropharyngeal and cloacal samples were obtained from poultry (n = 1,836) at 38 live-bird markets in 24 provinces in China between 2014 and 2015 (Table 1) [28], and 1,647 oropharyngeal and 1,696 cloacal samples from 1,836 birds were used in this investigation. The swabs from pigs and poultry were collected into tubes containing 400μl DNA/RNA Stabilization Buffer (Roche Molecular Biochemicals, IN, USA), and frozen at -80°C until DNA extraction.…”

“…The swabs from pigs and poultry were collected into tubes containing 400μl DNA/RNA Stabilization Buffer (Roche Molecular Biochemicals, IN, USA), and frozen at -80°C until DNA extraction. Swabs were centrifuged in the DNA/RNA Stabilization Buffer (3,000×g, 4°C for 5 min), and DNAs were extracted from the supernatants using the High Pure PCR Template Preparation Kit (Roche Diagnostic, USA) as described before [22, 28]. All samples from previous studies that had sufficient residual DNA extract were included in this investigation.…”