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158 result(s) for "Campylobacter fetus - isolation "
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Campylobacter fetus Infections in Humans: Exposure and Disease
Campylobacter fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided insight into sources. Source attribution of sporadic cases through case-control interviews has not been reported. The reservoirs for C. fetus are mainly cattle and sheep. Products from these animals are suspected as sources for human infections. Campylobacter fetus is rarely isolated from food, albeit selective isolation methods used in food microbiology are not suited for its detection. We hypothesize that the general population is regularly exposed to C. fetus through foods of animal origin, cross-contaminated foodstuffs, and perhaps other, as yet unidentified, routes. Campylobacter fetus infection should be suspected particularly in patients with nonspecific febrile illness who are immunocompromised or who may have been occupationally exposed to ruminants.
Time, temperature and media: the three keys to improve the recovery of Campylobacter fetus subsp. venerealis from preputial bull samples
The isolation of Campylobacter fetus subsp. venerealis (Cfv) from clinical samples is the gold standard for confirming cases of bovine genital campylobacteriosis, an important cause of infertility in cattle and a potential public health concern. Furthermore, isolation is also necessary for the development of autologous vaccines, characterization of strains for antimicrobial susceptibility patterns, etc. Nevertheless, the sensitivity of culture methods is usually low, and there is no standardized protocol to maximize the recovery of Cfv from clinical samples. The aim of the current study is to design a protocol for the culture of Cfv from preputial samples by evaluating the combination of different transport, enrichment and culture media considering the impact of certain factors (time between collection and enrichment, temperature, and use of filters). The use of modified Lander’s transport medium and storing the sample for 24 h at 21 ± 2 °C led to the highest recovery of Cfv CFUs. In contrast, the storage of the samples during 24–48 h in PBS and Thomann rarely allowed the recovery of Cfv regardless of the temperature. The enrichment medium yielding the best results was Preston (significantly higher recovery than Brucella medium), while Cfv could not be isolated with Bolton. Regarding our diagnostic assay (using Lander as transport medium and Preston as enrichment medium), the best protocol in terms of maximizing Cfv recovery as well as limiting contaminations is to culture the samples in i) solid media Preston or Skirrow, and ii) using 0.65 μm filters and incubating plates at 37 °C in microaerophilic conditions.
Virulence profiling of Campylobacter spp., C. jejuni and C. fetus subsp. fetus abortions rise in sheep farms in Kashmir, India
Campylobacter spp. are the leading causes of ovine abortions leading to severe economic losses and a source of bacterial food borne illness in humans, posing a major public health concern. This study reports an increase in Brucella negative abortions in sheep farms in Kashmir, India in the last few years. Screening of sheep farms was carried to rule out Campylobacter abortion. Three Government sheep breeding farms in the Kashmir valley and some other private flocks were screened for the presence of C. jejuni and C. fetus subsp. fetus. A total of 217 samples comprising of 200 swabs (rectal and vaginal swabs; 100 each) from clinically healthy animals, ten vaginal swabs from cases of abortion and seven abomasal contents of the aborted fetuses were collected from sheep breeding farm Khimber (District, Srinagar), sheep breeding farm Goabal, the Mountain Research Centre for sheep and goats (MRCSG, SKUAST-K) (District, Ganderbal) and from private sheep breeders were screened. In the present study a total of 15.2% of samples were positive for different Campylobacter spp. by PCR. C. jejuni and C. coli were detected individually or coexisting by PCR in the rectal swabs from all farms, while C. fetus subsp. fetus was detected only in the vaginal swabs from private sheep farms and abortion samples. Additionally, C. jejuni was also isolated from vaginal swabs. A total of 5, 20 and 18 samples were confirmed positive by PCR for C. fetus subsp. fetus, C. jejuni and C. coli, respectively. The Campylobacter isolates obtained in the present study were screened for flaA, cdtB, cadF, wlaN, pldA, virB and dnaJ virulence determinants. However, the isolates harboured flaA, cdtB and cadF virulence determinants only. The recovery of virulent Campylobacter isolates from healthy sheep fecal swabs in the present study may have longer human health implications. The presence of abortive strains of C. jejuni and C fetus subsp. fetus in sheep farms has long term economic implications in the Kashmir valley. This study emphasizes the need for efforts to be taken on farms to prevent animal infections and minimizing human exposure to these pathogens through proper hygiene and production practices as suggested by World Organization for Animal Health (OIE).
A novel real-time PCR assay for quantitative detection of Campylobacter fetus based on ribosomal sequences
Background Campylobacter fetus is a pathogen of major concern for animal and human health. The species shows a great intraspecific variation, with three subspecies: C. fetus subsp. fetus , C. fetus subsp. venerealis , and C. fetus subsp. testudinum . Campylobacter fetus fetus affects a broad range of hosts and induces abortion in sheep and cows. Campylobacter fetus venerealis is restricted to cattle and causes the endemic disease bovine genital campylobacteriosis, which triggers reproductive problems and is responsible for major economic losses. Campylobacter fetus testudinum has been proposed recently based on genetically divergent strains isolated from reptiles and humans. Both C. fetus fetus and C. fetus testudinum are opportunistic pathogens for immune-compromised humans. Biochemical tests remain as the gold standard for identifying C. fetus but the fastidious growing requirements and the lack of reliability and reproducibility of some biochemical tests motivated the development of molecular diagnostic tools. These methods have been successfully tested on bovine isolates but fail to detect some genetically divergent strains isolated from other hosts. The aim of the present study was to develop a highly specific molecular assay to identify and quantify C. fetus strains. Results We developed a highly sensitive real-time PCR assay that targets a unique region of the 16S rRNA gene. This assay successfully detected all C. fetus strains, including those that were negative for the cstA gene-based assay used as a standard for molecular C. fetus identification. The assay showed high specificity and absence of cross-reactivity with other bacterial species. The analytical testing of the assay was determined using a standard curve. The assay demonstrated a wide dynamic range between 10 2 and 107 genome copies per reaction, and a good reproducibility with small intra- and inter-assay variability. Conclusions The possibility to characterize samples in a rapid, sensitive and reproducible way makes this assay a good option to establish a new standard in molecular identification and quantification of C. fetus species.
First Case Report of Mycotic Abdominal Aortic Aneurysm Caused by Campylobacter fetus in Serbia
Background: Due to its distinct vascular tropism, Campylobacter fetus is recognized as a significant cause of severe systemic infections, especially in immunocompromised individuals, while it is rarely reported as a cause of gastrointestinal infections. Methods: A rare case of mycotic abdominal aortic aneurysm associated with Campylobacter fetus detected on the aneurysm wall itself was described. Results: A 68-year-old male was admitted to the hospital due to severe abdominal pain. The patient was afebrile, hemodynamically stable with elevated C-reactive protein levels. A physical examination revealed a palpable, pulsatile, tender mass located in the periumbilical region. Ultrasonography and multi-slice computer tomography angiography (MSCTA) identified an infrarenal abdominal aortic aneurysm with a maximum diameter of 6.5 cm, showing suspicious signs of dissection. Aneurysmectomy with Dacron tube graft interposition was performed. Although the blood cultures remained negative, the culture of the aneurysmal wall grew Campylobacter fetus, enabling early diagnosis and targeted antibiotic therapy. The patient was treated with meropenem for two weeks, followed by amoxicillin-clavulanate for another two weeks after hospital discharge. Conclusions: Campylobacter fetus associated with abdominal aortic aneurysms represents a life-threatening condition, posing a significant challenge in vascular surgery. Due to the lack of clear guidelines on antibiotic susceptibility testing and the treatment of infections associated with this pathogen, enhanced surveillance of Campylobacter fetus is necessary in both human and veterinary medicine.
A rural worker infected with a bovine-prevalent genotype of Campylobacter fetus subsp. fetus supports zoonotic transmission and inconsistency of MLST and whole-genome typing
Whole-genome characterisation in clinical microbiology enables to detect trends in infection dynamics and disease transmission. Here, we report a case of bacteraemia due to Campylobacter fetus subsp. fetus in a rural worker under cancer treatment that was diagnosed with cellulitis; the patient was treated with antibiotics and recovered. The routine typing methods were not able to identify the microorganism causing the infection, so it was further analysed by molecular methods and whole-genome sequencing. The multi-locus sequence typing (MLST) revealed the presence of the bovine-associated ST-4 genotype. Whole-genome comparisons with other C. fetus strains revealed an inconsistent phylogenetic position based on the core genome, discordant with previous ST-4 strains. To the best of our knowledge, this is the first C. fetus subsp. fetus carrying the ST-4 isolated from humans and represents a probable case of zoonotic transmission from cattle.
Campylobacter fetus bloodstream infection: risk factors and clinical features
In this paper, we report 21 cases of Campylobacter fetus bloodstream infection observed in our institution over a 9-year period. The median age of the patients was 78 years. Most of them (62%) had a significant underlying disease, such as diabetes, immunodeficiency or cardiovascular disease. The main clinical features were fever with (62% of cases) or without (38%) extra-intestinal symptoms. These included mycotic aneurysm of the abdominal aorta (24%) and cellulitis (19%). Antibiotic treatment was mainly based on amoxicilline-clavulanate (57%) or imipenem (21%), for a median duration of 28 days. A favourable outcome was observed in 72% of cases. Death directly attributable to infection was observed for three patients, due to the rupture of an infected aneurysm or relapsing bloodstream infection with septic shock. All patients initially treated with imipenem had a favourable outcome. This report adds evidence that C. fetus bloodstream infection should be suspected in elderly patients with fever, immunodeficiency and cardiovascular damages. Imipenem seems to be the most active drug, especially in severe cases.