scholarly journals Detection of Prosthetic Hip Infection at Revision Arthroplasty by Immunofluorescence Microscopy and PCR Amplification of the Bacterial 16S rRNA Gene

1999 ◽  
Vol 37 (10) ◽  
pp. 3281-3290 ◽  
Author(s):  
Michael M. Tunney ◽  
Sheila Patrick ◽  
Martin D. Curran ◽  
Gordon Ramage ◽  
Donna Hanna ◽  
...  

In this study the detection rates of bacterial infection of hip prostheses by culture and nonculture methods were compared for 120 patients with total hip revision surgery. By use of strict anaerobic bacteriological practice during the processing of samples and without enrichment, the incidence of infection by culture of material dislodged from retrieved prostheses after ultrasonication (sonicate) was 22%. Bacteria were observed by immunofluorescence microscopy in 63% of sonicate samples with a monoclonal antibody specific forPropionibacterium acnes and polyclonal antiserum specific for Staphylococcus spp. The bacteria were present either as single cells or in aggregates of up to 300 bacterial cells. These aggregates were not observed without sonication to dislodge the biofilm. Bacteria were observed in all of the culture-positive samples, and in some cases in which only one type of bacterium was identified by culture, both coccoid and coryneform bacteria were observed by immunofluorescence microscopy. Bacteria from skin-flake contamination were readily distinguishable from infecting bacteria by immunofluorescence microscopy. Examination of skin scrapings did not reveal large aggregates of bacteria but did reveal skin cells. These were not observed in the sonicates. Bacterial DNA was detected in 72% of sonicate samples by PCR amplification of a region of the bacterial 16S rRNA gene with universal primers. All of the culture-positive samples were also positive for bacterial DNA. Evidence of high-level infiltration either of neutrophils or of lymphocytes or macrophages into associated tissue was observed in 73% of patients. Our results indicate that the incidence of prosthetic joint infection is grossly underestimated by current culture detection methods. It is therefore imperative that current clinical practice with regard to the detection and subsequent treatment of prosthetic joint infection be reassessed in the light of these results.

2011 ◽  
Vol 50 (3) ◽  
pp. 583-589 ◽  
Author(s):  
M. Marin ◽  
J. M. Garcia-Lechuz ◽  
P. Alonso ◽  
M. Villanueva ◽  
L. Alcala ◽  
...  

2011 ◽  
Vol 24 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Doug E. Antibus ◽  
Laura G. Leff ◽  
Brenda L. Hall ◽  
Jenny L. Baeseman ◽  
Christopher B. Blackwood

AbstractThe McMurdo Dry Valleys possess a cold and dry climate which favours biomolecular preservation, and present the possibility for preservation of biological materials over long timescales. We examined patterns of bacterial DNA abundance and diversity in algal mats from 8–26 539 years of age. Bacterial DNA abundance was inferred from extractable DNA quantity and quantitative polymerase chain reaction targeting the bacterial 16S rRNA gene. Because damage to bacterial DNA could limit its availability for polymerase chain reaction, the efficacy of DNA repair by a commercially available kit was also examined. Polymerase chain reaction amplicons of the bacterial 16S rRNA gene were obtained from seven of eight samples. Bulk DNA abundance and bacterial 16S rRNA gene copy number of template DNA declined with increasing sample age consistent with expectations of accumulation of DNA damage in ancient materials. Clone libraries revealed age related patterns of abundance for some bacterial phylogenetic groups. For example, Firmicutes and several other lineages were abundant in ancient samples, but Cyanobacteria were absent. This points to a biased persistence of bacterial lineages that change over time since photosynthesis was active.


2019 ◽  
Vol 52 (1) ◽  
pp. 167-169 ◽  
Author(s):  
Caroline Rouard ◽  
Sabine Pereyre ◽  
Sophie Abgrall ◽  
Christelle Guillet-Caruba ◽  
Pierre Diviné ◽  
...  

2019 ◽  
Vol 4 (2) ◽  
pp. 224-228
Author(s):  
Michael A Lane ◽  
Neeraja Ganeshraj ◽  
Alice Gu ◽  
David K Warren ◽  
Carey-Ann D Burnham

Abstract Introduction Medical management of prosthetic joint infections (PJIs) relies on the identification of causative organisms through traditional culture-based approaches to guide therapy. However, diagnosis of many PJIs remains challenging, with many clinically apparent infections remaining culture-negative. Molecular diagnostics have the potential to increase diagnostic yield, particularly among culture-negative PJIs. Methods Bone, tissue, or synovial fluid from patients with clinically identified PJIs were collected for inclusion in this study. Samples were assessed with traditional cultures and classified as culture-positive or -negative after 48 h. Samples subsequently underwent a Staphylococcus aureus-/Kingella kingae-specific PCR followed by a 16s rRNA gene PCR. Results A total of 77 unique patients with clinically identified PJIs contributed a total of 89 samples for inclusion in the study. There were 54 culture-negative and 35 culture-positive samples evaluated. The sensitivity and specificity of S. aureus PCR in culture-positive samples was 57.1% (95% CI, 34.1%–78.1%) and 92.9% (95% CI, 66.1%–98.9%), respectively. Among culture-positive samples, 16s rRNA gene PCR correctly identified 3 of 21 (14.3%) samples with S. aureus and 2 of 5 (40%) samples with Streptococcus spp. All molecular tests were negative in those with clinically identified, culture-negative PJI. Conclusions Our study suggests that these diagnostic tools have a limited role in PJI diagnosis.


2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Asieh Bolandi ◽  
Saam Torkan ◽  
Iman Alavi

In despite of the high clinical impact of Helicobacter pylori, its exact sources and routes of transmission are unknown. Dogs may play an imperative role in the transmission of H. pylori to humans. The current investigation was done to study the status of vacA and cagA genotypes in the H. pylori strains of dogs. One-hundred and fifty fecal samples were collected from healthy and complicated household dogs. Genomic DNA was extracted from fecal samples and presence of 16S rRNA gene was studied using the PCR amplification. Distribution of vacA and cagA genotypes were studied by the multiplex PCR. Thirteen out of 150 fecal samples (8.66%) were positive for H. pylori 16S rRNA gene. Prevalence of H. pylori in healthy and complicated dogs were 5.55% and 8.57%, respectively. Male had the higher prevalence of H. pylori (P=0.038). The most commonly detected genotypes among the H. pylori strains were vacAs1A (61.53%), cagA (38.46%), vacAm1a (38.46%), vacAs2 (30.76%) and vacAm2 (30.76%). The most commonly detected combined genotypes were s1aCagA (30.76%), s1am1a (23.07%), s2m1a (23.07%) and s2CagA (23.07%). Iranian household dogs harbor H. pylori in their fecal samples similar in genotypes of the vacA and cagA alleles which suggest that complicated and even healthy dogs may be the latent host of the H. pylori and its genotypes. However, supplementary studies are required to found the exact role of dogs as a definitive host of the H. pylori.


2017 ◽  
Vol 83 (12) ◽  
Author(s):  
Laura Glendinning ◽  
Steven Wright ◽  
Peter Tennant ◽  
Andrew C. Gill ◽  
David Collie ◽  
...  

ABSTRACT The lung microbiota is commonly sampled using relatively invasive bronchoscopic procedures. Exhaled breath condensate (EBC) collection potentially offers a less invasive alternative for lung microbiota sampling. We compared lung microbiota samples retrieved by protected specimen brushings (PSB) and exhaled breath condensate collection. We also sought to assess whether aerosolized antibiotic treatment would influence the lung microbiota and whether this change could be detected in EBC. EBC was collected from 6 conscious sheep and then from the same anesthetized sheep during mechanical ventilation. Following the latter EBC collection, PSB samples were collected from separate sites within each sheep lung. On the subsequent day, each sheep was then treated with nebulized colistimethate sodium. Two days after nebulization, EBC and PSB samples were again collected. Bacterial DNA was quantified using 16S rRNA gene quantitative PCR. The V2-V3 region of the 16S rRNA gene was amplified by PCR and sequenced using Illumina MiSeq. Quality control and operational taxonomic unit (OTU) clustering were performed with mothur. The EBC samples contained significantly less bacterial DNA than the PSB samples. The EBC samples from anesthetized animals clustered separately by their bacterial community compositions in comparison to the PSB samples, and 37 bacterial OTUs were identified as differentially abundant between the two sample types. Despite only low concentrations of colistin being detected in bronchoalveolar lavage fluid, PSB samples were found to differ by their bacterial compositions before and after colistimethate sodium treatment. Our findings indicate that microbiota in EBC samples and PSB samples are not equivalent. IMPORTANCE Sampling of the lung microbiota usually necessitates performing bronchoscopic procedures that involve a hospital visit for human participants and the use of trained staff. The inconvenience and perceived discomfort of participating in this kind of research may deter healthy volunteers and may not be a safe option for patients with advanced lung disease. This study set out to evaluate a less invasive method for collecting lung microbiota samples by comparing samples taken via protected specimen brushings (PSB) to those taken via exhaled breath condensate (EBC) collection. We found that there was less bacterial DNA in EBC samples compared with that in PSB samples and that there were differences between the bacterial communities in the two sample types. We conclude that while EBC and PSB samples do not produce equivalent microbiota samples, the study of the EBC microbiota may still be of interest.


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