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

Puysseleyr, Kristien De; Puysseleyr, Leentje De; Dhondt, Hendrik; Geens, Tom; Braeckman, Lutgart; Morré, Servaas A.; Cox, Eric; Vanrompay, Daisy

doi:10.1186/s12879-014-0560-x

Cited by 51 publications

(40 citation statements)

References 27 publications

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“…Furthermore, the in vitro susceptibility test of Chlamydia to antimicrobials is not affordable for all laboratories as it is a time-consuming assay. Consequently, tet (C) PCR is more commonly used for detection than the antibiotic susceptibility assay [15, 29]. In the current study, we found clear evidence for the benefit of isolating samples prior to molecular analysis over tet (C) PCR directly from clinical swabs as well as the superiority of the tetracycline susceptibility assay with and without PCR analysis over tet (C) detection alone.…”

Section: Discussionsupporting

confidence: 56%

Selective Pressure Promotes Tetracycline Resistance of Chlamydia Suis in Fattening Pigs

et al. 2016

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In pigs, Chlamydia suis has been associated with respiratory disease, diarrhea and conjunctivitis, but there is a high rate of inapparent C. suis infection found in the gastrointestinal tract of pigs. Tetracycline resistance in C. suis has been described in the USA, Italy, Switzerland, Belgium, Cyprus and Israel. Tetracyclines are commonly used in pig production due to their broad-spectrum activity and relatively low cost. The aim of this study was to isolate clinical C. suis samples in cell culture and to evaluate their antibiotic susceptibility in vitro under consideration of antibiotic treatment on herd level.Swab samples (n = 158) identified as C. suis originating from 24 farms were further processed for isolation, which was successful in 71% of attempts with a significantly higher success rate from fecal swabs compared to conjunctival swabs. The farms were divided into three treatment groups: A) farms without antibiotic treatment, B) farms with prophylactic oral antibiotic treatment of the whole herd consisting of trimethoprime, sulfadimidin and sulfathiazole (TSS), or C) farms giving herd treatment with chlortetracycline with or without tylosin and sulfadimidin (CTS). 59 isolates and their corresponding clinical samples were selected and tested for the presence or absence of the tetracycline resistance class C gene [tet(C)] by conventional PCR and isolates were further investigated for their antibiotic susceptibility in vitro. The phenotype of the investigated isolates was either classified as tetracycline sensitive (Minimum inhibitory concentration [MIC] < 2 μg/ml), intermediate (2 μg/ml ≤ MIC < 4 μg/ml) or resistant (MIC ≥ 4 μg/ml). Results of groups and individual pigs were correlated with antibiotic treatment and time of sampling (beginning/end of the fattening period). We found clear evidence for selective pressure as absence of antibiotics led to isolation of only tetracycline sensitive or intermediate strains whereas tetracycline treatment resulted in a greater number of tetracycline resistant isolates.

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Section: Discussionsupporting

confidence: 56%

Selective Pressure Promotes Tetracycline Resistance of Chlamydia Suis in Fattening Pigs

et al. 2016

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“…However, detection of chlamydial organisms in Australian pigs raises new questions. Whilst globally C. suis is recognized as the most relevant chlamydial pig pathogen with demonstrated zoonotic potential (De Puysseleyr et al, ), with C. abortus, C. psittaci, and/or C. pecorum also regularly detected (Hoffmann et al, ), almost nothing is known about chlamydial infections in Australian pigs. The detection of C. pecorum in ocular and rectal samples from two pigs was not surprising to us, as the three pigs were from the same C. pecorum ‐endemic region as the sheep and cattle.…”

Section: Discussionmentioning

confidence: 99%

Detection of a range of genetically diverse chlamydiae in Australian domesticated and wild ungulates

Jelocnik

Taylor-Brown

O'Dea

et al. 2019

Transbound Emerg Dis

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Summary Chlamydiae are globally widespread obligate intracellular bacteria, which several species are a well‐recognized threat to human and animal health. In Australia, the most successful chlamydial species are the infamous koala pathogen C. pecorum, and C. psittaci, an emerging pathogen associated with zoonotic events. Little is known about infections caused by other chlamydial organisms in Australian livestock or wildlife. Considering that these hosts can be encountered by humans at the animal/human interface, in this study, we investigated genetic diversity of chlamydial organisms infecting Australian domesticated and wild ungulates. A total of 185 samples from 129 domesticated (cattle, horses, sheep, and pigs) and 29 wild (deer) ungulate hosts were screened with C. pecorum and C. psittaci species‐specific assays, followed by a screen with pan‐Chlamydiales assay. Overall, chlamydial DNA was detected in 120/185 (65%) samples, including all ungulate hosts. Species‐specific assays further revealed that C. pecorum and C. psittaci DNA were detected in 27% (50/185) and 6% (11/185) of the samples, respectively, however from domesticated hosts only. A total of 46 “signature” 16S rRNA sequences were successfully resolved by sequencing and were used for phylogenetic analyses. Sequence analyses revealed that genetically diverse novel as well as traditional chlamydial organisms infect an expanded range of ungulate hosts in Australia. Detection of the C. psittaci and C. pecorum in livestock, and novel taxa infecting horses and deer raises questions about the genetic make‐up and pathogenic potential of these organisms, but also concerns about risks of spill‐over between livestock, humans, and native wildlife.

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“…All of these factors might have severe consequences for human health, considering that both C. suis and C. trachomatis DNA have been detected simultaneously in the eyes of trachoma patients in Nepal. Moreover, C. suis was isolated from ocular and rectal samples originating from slaughterhouse workers and pig farmers [20][21][22][23]. The use of sub-inhibitory concentrations of tetracycline, especially in the presence of tetracycline-resistant C. suis isolates, could lead to treatment failure and the selection of tetracycline resistance on herd-level with the potential recurrence of clinical signs [24,25].…”

Section: Introductionmentioning

confidence: 99%

Isolation of Tetracycline-Resistant Chlamydia suis from a Pig Herd Affected by Reproductive Disorders and Conjunctivitis

et al. 2020

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Due to various challenges in diagnosing chlamydiosis in pigs, antibiotic treatment is usually performed before any molecular or antibiotic susceptibility testing. This could increase the occurrence of tetracycline-resistant Chlamydia (C.) suis isolates in the affected pig population and potentiate the reoccurrence of clinical signs. Here, we present a case of an Austrian pig farm, where tetracycline resistant and sensitive C. suis isolates were isolated from four finishers with conjunctivitis. On herd-level, 10% of the finishers suffered from severe conjunctivitis and sows showed a high percentage of irregular return to estrus. Subsequent treatment of whole-herd using oxytetracycline led to a significant reduction of clinical signs. Retrospective antibiotic susceptibility testing revealed tetracycline resistance and decreased susceptibility to doxycycline in half of the ocular C. suis isolates, and all isolates were able to partially recover following a single-dose tetracycline treatment in vitro. These findings were later confirmed in vivo, when all former clinical signs recurred three months later. This case report raises awareness of tetracycline resistance in C. suis and emphasizes the importance of preventative selection of tetracycline resistant C. suis isolates.

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

Cited by 51 publications

References 27 publications

Selective Pressure Promotes Tetracycline Resistance of Chlamydia Suis in Fattening Pigs

Selective Pressure Promotes Tetracycline Resistance of Chlamydia Suis in Fattening Pigs

Detection of a range of genetically diverse chlamydiae in Australian domesticated and wild ungulates

Isolation of Tetracycline-Resistant Chlamydia suis from a Pig Herd Affected by Reproductive Disorders and Conjunctivitis

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