scholarly journals Use of Universal 16S rRNA Gene PCR as a Diagnostic Tool for Venous Access Port-Related Bloodstream Infections

2012 ◽  
Vol 51 (3) ◽  
pp. 799-804 ◽  
Author(s):  
M. Guembe ◽  
M. Marín ◽  
P. Martín-Rabadán ◽  
A. Echenagusia ◽  
F. Camúñez ◽  
...  
2020 ◽  
Vol 69 (11) ◽  
pp. 1273-1284
Author(s):  
Esingül Kaya ◽  
Lara Tollapi ◽  
Alberto Pastore ◽  
Giacomo Aringhieri ◽  
Giuseppantonio Maisetta ◽  
...  

Introduction. Totally implanted venous access ports (TIVAPs) are widely used in patients receiving long-term chemotherapy but may lead to serious complications such as catheter-related bloodstream infections (CRBSIs). Diagnosis of CRBSI requires catheter culture, but there is no consensus on microbiological culture methods to be adopted. Aim. To compare three different procedures to recover bacterial cells from colonized catheters and to determine which section of the TIVAP (i.e. tip, septum, reservoir) is the probable source of infection. To investigate the correlation between blood culture results and TIVAP culture in order to get further evidence about the utility of differential time to positivity (DTP) as a diagnostic tool before TIVAP removal. Hypothesis/Gap statement. Comparisons of different diagnostic procedures for catheter culture have been rarely reported for TIVAPs. We hypothesized that the optimization of methods to recover micro-organisms from different parts of TIVAPs may help to decrease the number of false-negative results in the diagnosis of TIVAP-related bloodstream infections. Methodology. A total of 53 TIVAPs removed because of suspected infection (n=36) or end of use (n=17) were evaluated. The reservoir, the septum and the catheter tip were separated and subjected to different treatments for the recovery of adherent micro-organisms: (a) flushing of the catheter lumen, (b) sonication and flushing, (c) treatment with dithiothreitol and flushing. The three methods were also evaluated in an in vitro catheter infection model with Staphylococcus epidermidis . Culture results were compared to those obtained from paired blood cultures drawn from TIVAP and peripheral vein and to the relative DTP. Results. The results obtained demonstrated that vigorous flushing/vortexing of the catheter lumen/septum, allows the recovery of a number of micro-organisms comparable to that of more complex procedures such as sonication or chemical treatment. Among 24 positive TIVAP-cultures, nine were tip-culture negative, whereas the corresponding reservoirs and septa were culture positive. A good correlation was observed between DTP and TIVAP cultures (P<0.001). Conclusions. The results support the evidence that sending the port reservoir in addition to the catheter tip to the microbiology laboratory may increase the sensitivity and the accuracy of CRBSI diagnosis. Moreover, when a TIVAP-related infection is suspected, DTP is a useful diagnostic tool to decide between device removal or a more conservative approach.


2015 ◽  
Vol 41 (1) ◽  
pp. 51-58
Author(s):  
Mohammad Shamimul Alam ◽  
Hawa Jahan ◽  
Rowshan Ara Begum ◽  
Reza M Shahjahan

Heteropneustesfossilis, Clariasbatrachus and C. gariepinus are three major catfishes ofecological and economic importance. Identification of these fish species becomes aproblem when the usual external morphological features of the fish are lost or removed,such as in canned fish. Also, newly hatched fish larva is often difficult to identify. PCRsequencingprovides accurate alternative means of identification of individuals at specieslevel. So, 16S rRNA genes of three locally collected catfishes were sequenced after PCRamplification and compared with the same gene sequences available from othergeographical regions. Multiple sequence alignment of the 16S rRNA gene fragments ofthe catfish species has revealed polymorphic sites which can be used to differentiate thesethree species from one another and will provide valuable insight in choosing appropriaterestriction enzymes for PCR-RFLP based identification in future. Asiat. Soc. Bangladesh, Sci. 41(1): 51-58, June 2015


2020 ◽  
Vol 139 ◽  
pp. 161-174
Author(s):  
R Palmer ◽  
GTA Fleming ◽  
S Glaeser ◽  
T Semmler ◽  
A Flamm ◽  
...  

During 1992 and 1993, a bacterial disease occurred in a seawater Atlantic salmon Salmo salar farm, causing serious mortalities. The causative agent was subsequently named as Oceanivirga salmonicida, a member of the Leptotrichiaceae. Searches of 16S rRNA gene sequence databases have shown sequence similarities between O. salmonicida and uncultured bacterial clones from the digestive tracts of marine mammals. In the current study, oral samples were taken from stranded dolphins (common dolphin Delphinus delphis, striped dolphin Stenella coeruleoalba) and healthy harbour seals Phoca vitulina. A bacterium with growth characteristics consistent with O. salmonicida was isolated from a common dolphin. The isolate was confirmed as O. salmonicida, by comparisons to the type strain, using 16S rRNA gene, gyrB, groEL, and recA sequence analyses, average nucleotide identity analysis, and MALDI-TOF mass spectrometry. Metagenomic analysis indicated that the genus Oceanivirga represented a significant component of the oral bacterial microbiomes of the dolphins and seals. However, sequences consistent with O. salmonicida were only found in the dolphin samples. Analyses of marine mammal microbiome studies in the NCBI databases showed sequences consistent with O. salmonicida from the common dolphin, striped dolphin, bottlenose dolphin Tursiops truncatus, humpback whale Megaptera novaeangliae, and harbour seal. Sequences from marine environmental studies in the NCBI databases showed no sequences consistent with O. salmonicida. The findings suggest that several species of marine mammals are natural hosts of O. salmonicida.


2020 ◽  
Author(s):  
CC Kim ◽  
WJ Kelly ◽  
ML Patchett ◽  
GW Tannock ◽  
Z Jordens ◽  
...  

© 2017 IUMS. A novel anaerobic pectinolytic bacterium (strain 14T) was isolated from human faeces. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 14T belonged to the family Ruminococcaceae, but was located separately from known clostridial clusters within the taxon. The closest cultured relative of strain 14T was Acetivibrio cellulolyticus (89.7% sequence similarity). Strain 14T shared ~99% sequence similarity with cloned 16S rRNA gene sequences from uncultured bacteria derived from the human gut. Cells were Gram-stain-positive, non-motile cocci approximately 0.6μm in diameter. Strain 14T fermented pectins from citrus peel, apple, and kiwifruit as well as carbohydrates that are constituents of pectins and hemicellulose, such as galacturonic acid, xylose, and arabinose. TEM images of strain 14T, cultured in association with plant tissues, suggested extracellular fibrolytic activity associated with the bacterial cells, forming zones of degradation in the pectin-rich regions of middle lamella. Phylogenetic and phenotypic analysis supported the differentiation of strain 14T as a novel genus in the family Ruminococcaceae. The name Monoglobus pectinilyticus gen. nov., sp. nov. is proposed; the type strain is 14T (JCM 31914T=DSM 104782T).


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