scholarly journals Evaluation of Procedures for the Collection, Processing, and Analysis of Biomolecules from Low-Biomass Surfaces

2011 ◽  
Vol 77 (9) ◽  
pp. 2943-2953 ◽  
Author(s):  
K. Kwan ◽  
M. Cooper ◽  
M. T. La Duc ◽  
P. Vaishampayan ◽  
C. Stam ◽  
...  

ABSTRACTTo comprehensively assess microbial diversity and abundance via molecular-analysis-based methods, procedures for sample collection, processing, and analysis were evaluated in depth. A model microbial community (MMC) of known composition, representative of a typical low-biomass surface sample, was used to examine the effects of variables in sampling matrices, target cell density/molecule concentration, and cryogenic storage on the overall efficacy of the sampling regimen. The MMC used in this study comprised 11 distinct species of bacterial, archaeal, and fungal lineages associated with either spacecraft or clean-room surfaces. A known cellular density of MMC was deposited onto stainless steel coupons, and after drying, a variety of sampling devices were used to recover cells and biomolecules. The biomolecules and cells/spores recovered from each collection device were assessed by cultivable and microscopic enumeration, and quantitative and species-specific PCR assays. rRNA gene-based quantitative PCR analysis showed that cotton swabs were superior to nylon-flocked swabs for sampling of small surface areas, and for larger surfaces, biological sampling kits significantly outperformed polyester wipes. Species-specific PCR revealed differential recovery of certain species dependent upon the sampling device employed. The results of this study empower current and future molecular-analysis-based microbial sampling and processing methodologies.

2009 ◽  
Vol 72 (7) ◽  
pp. 1491-1495 ◽  
Author(s):  
DANIELA PENTIMALLI ◽  
NICOLETTE PEGELS ◽  
TERESA GARCÍA ◽  
ROSARIO MARTÍN ◽  
ISABEL GONZÁLEZ

An enrichment PCR assay using species-specific primers was developed for the detection of Arcobacter butzleri, Arcobacter cryaerophilus, Arcobacter skirrowii, and Arcobacter cibarius in chicken meat. Primers for A. cryaerophilus, A. skirrowii, and A. cibarius were designed based on the gyrA gene to amplify nucleic acid fragments of 212, 257, and 145 bp, respectively. The A. butzleri–specific primers were designed flanking a 203-bp DNA fragment in the 16S rRNA gene. The specificity of the four primer pairs was assessed by PCR analysis of DNA from a panel of Arcobacter species, related Campylobacter, Helicobacter species, and other food bacteria. The applicability of the method was then validated by testing 42 fresh retail-purchased chicken samples in the PCR assay. An 18-h selective preenrichment step followed by PCR amplification with the four Arcobacter primer sets revealed the presence of Arcobacter spp. in 85.7% of the retail chicken samples analyzed. A. butzleri was the only species present in 50% of the samples, and 35.7% of the samples were positive for both A. butzleri and A. cryaerophilus. A. skirrowii and A. cibarius were not detected in any of the chicken samples analyzed. The enrichment PCR assay developed is a specific and rapid alternative for the survey of Arcobacter contamination in meat.


Parasitology ◽  
2018 ◽  
Vol 145 (9) ◽  
pp. 1147-1150 ◽  
Author(s):  
Hamza Avcioglu ◽  
Esin Guven ◽  
Ibrahim Balkaya ◽  
Ridvan Kirman

AbstractEchinococcus multilocularis is the causative agent of alveolar echinococcosis (AE), one of the most threatening zoonoses in Eurasia. Human AE is widespread in the Erzurum region of Turkey, but the situation of the disease in intermediate and definitive hosts is unknown. A Eurasian lynx (Lynx lynx) was killed in a traffic accident in the north of Erzurum, and was taken to our laboratory. Sedimentation and counting technique (SCT), DNA isolation and polymerase chain reaction (PCR) analysis were performed. The SCT results showed that the lynx was infected with E. multilocularis with a medium (745 worms) worm burden. The DNA of adult worms obtained from the lynx was analyzed with a species-specific PCR, and the worms were confirmed to be E. multilocularis by 12S rRNA gene sequence analysis. This is the first report of E. multilocularis from Eurasian lynx in Turkey.


Author(s):  
Hagit Dafni ◽  
Lea Greenfeld ◽  
Roni Oren ◽  
Alon Harmelin

The precise identification of rodent Pasteurellaceae is known to be highly challenging. An unknown strain of Pasteurellaceae appeared and rapidly spread throughout our animal facilities. Standard microbiology, combined with biochemical analysis, suggested that the bacteria strain was Rodentibacter pneumotropicus or R. heylii. We submitted samples of the unknown bacteria and known isolates of R. pneumotropicus, R. heylii, and Muribacter muris, to 2 service laboratories that provide animal health monitoring. Results of microbiology tests performed by both laboratories, species-specific PCR analysis performed by one laboratory, and independent 16S rRNA gene sequencing yielded identical identification of the unknown bacteria as Pasteurellaceae (Pasteurella spp.) and not R. pneumotropicus or R. heylii. In contrast, the similarly intended PCR assay performed by the other laboratory identified the bacteria as R. heylii. Careful evaluation of all of the results led us to conclude that the correct identification of the bacteria is Pasteurellaceae. From our experience, we recommend that a combination of several methods should be used to achieve correct identification of rodent Pasteurellaceae. Specifically, we advise that all primer sets used should be disclosed when reporting PCR test results, including in health reports provided by service laboratories and animal vendors. Careful, correct, and informative health monitoring reports are most beneficial to animal researchers and caretakers who might encounter the presence and effects of rodent Pasteurellaceae.


2003 ◽  
Vol 69 (11) ◽  
pp. 6380-6385 ◽  
Author(s):  
R. Temmerman ◽  
L. Masco ◽  
T. Vanhoutte ◽  
G. Huys ◽  
J. Swings

ABSTRACT The taxonomic characterization of a bacterial community is difficult to combine with the monitoring of its temporal changes. None of the currently available identification techniques are able to visualize a “complete” community, whereas techniques designed for analyzing bacterial ecosystems generally display limited or labor-intensive identification potential. This paper describes the optimization and validation of a nested-PCR-denaturing gradient gel electrophoresis (DGGE) approach for the species-specific analysis of bifidobacterial communities from any ecosystem. The method comprises a Bifidobacterium-specific PCR step, followed by purification of the amplicons that serve as template DNA in a second PCR step that amplifies the V3 and V6-V8 regions of the 16S rRNA gene. A mix of both amplicons is analyzed on a DGGE gel, after which the band positions are compared with a previously constructed database of reference strains. The method was validated through the analysis of four artificial mixtures, mimicking the possible bifidobacterial microbiota of the human and chicken intestine, a rumen, and the environment, and of two fecal samples. Except for the species Bifidobacterium coryneforme and B. indicum, all currently known bifidobacteria originating from various ecosystems can be identified in a highly reproducible manner. Because no further cloning and sequencing of the DGGE bands is necessary, this nested-PCR-DGGE technique can be completed within a 24-h span, allowing the species-specific monitoring of temporal changes in the bifidobacterial community.


2015 ◽  
Vol 65 (Pt_12) ◽  
pp. 4424-4433 ◽  
Author(s):  
Jakeline Renata Marçon Delamuta ◽  
Renan Augusto Ribeiro ◽  
Ernesto Ormeño-Orrillo ◽  
Marcia Maria Parma ◽  
Itamar Soares Melo ◽  
...  

Biological nitrogen fixation is a key process for agricultural production and environmental sustainability, but there are comparatively few studies of symbionts of tropical pasture legumes, as well as few described species of the genus Bradyrhizobium, although it is the predominant rhizobial genus in the tropics. A detailed polyphasic study was conducted with two strains of the genus Bradyrhizobium used in commercial inoculants for tropical pastures in Brazil, CNPSo 1112T, isolated from perennial soybean (Neonotonia wightii), and CNPSo 2833T, from desmodium (Desmodium heterocarpon). Based on 16S-rRNA gene phylogeny, both strains were grouped in the Bradyrhizobium elkanii superclade, but were not clearly clustered with any known species. Multilocus sequence analysis of three (glnII, gyrB and recA) and five (plus atpD and dnaK) housekeeping genes confirmed that the strains are positioned in two distinct clades. Comparison with intergenic transcribed spacer sequences of type strains of described species of the genus Bradyrhizobium showed similarity lower than 93.1 %, and differences were confirmed by BOX-PCR analysis. Nucleotide identity of three housekeeping genes with type strains of described species ranged from 88.1 to 96.2 %. Average nucleotide identity of genome sequences showed values below the threshold for distinct species of the genus Bradyrhizobium ( < 90.6 %), and the value between the two strains was also below this threshold (91.2 %). Analysis of nifH and nodC gene sequences positioned the two strains in a clade distinct from other species of the genus Bradyrhizobium. Morphophysiological, genotypic and genomic data supported the description of two novel species in the genus Bradyrhizobium, Bradyrhizobium tropiciagri sp. nov. (type strain CNPSo 1112T = SMS 303T = BR 1009T = SEMIA 6148T = LMG 28867T) and Bradyrhizobium embrapense sp. nov. (type strain CNPSo 2833T = CIAT 2372T = BR 2212T = SEMIA 6208T = U674T = LMG 2987).


Author(s):  
Vibha Yadav ◽  
Rajesh Kumar Joshi ◽  
Namita Joshi ◽  
Amit Kumar ◽  
Satyavrat Singh

Background: Among enterobacteria E. coli and Klebsiella spp. are of great concern in health care settings, as these bacteria sometimes may contaminate the milk due to unhygienic practices and poor udder condition which have been associated with various illnesses. Therefore, this study aimed to detect the carbapenem resistant E. coli and Klebsiella spp. of bovine milk origin with regard to the risk of human transfer via the food chain in community. Methods: Total 240 samples were collected from Ayodhya and Sultanpur districts of Eastern Plain Zone of Uttar Pradesh (India). Confirmation of E. coli and Klebsiella spp. isolates was done by using species specific uidA and 16S rRNA gene, respectively. Then, carbapenemase positive E. coli and Klebsiella spp. were confirmend by DDST, MBL E-strip test and PCR analysis by targeting (bla-NDM, bla-OXA-48 and bla-KPC). Antibiogram of all carbapenemase positive isolates was performed against 20 antibiotics of 12 different classes. Result: In the present study, total 74(30.83%) isolates were identified including 55(22.92%) E. coli and 19(7.92%) Klebsiella spp. by PCR, out of which 12(16.21%) isolates were confirmed as carbapenemase producers comprising 7(12.72%) E. coli and 5(26.31%) Klebsiella spp by DDST and E-strip. All carbapenemase positive E. coli were found 100% sensitive to polymyxin-B and chloramphenicol, while all Klebsiella spp. were 100% sensitive to amikacin and polymyxin-B. Resistance against imipenem, meropenem, cefotaxime, cefpodoxime, ceftazidime, ceftriazone, aztreonam and ampicillin ranged between 80.0%-100%. All carbapenemase positive isolates were found multidrug resistant. Carbapenemase genes bla-NDM and bla-KPC were detected in E. coli while bla-OXA-48 and bla-KPC were detected in Klebsiella spp.


2005 ◽  
Vol 55 (2) ◽  
pp. 713-717 ◽  
Author(s):  
Kurt Houf ◽  
Stephen L. W. On ◽  
Tom Coenye ◽  
Jan Mast ◽  
Jan Van Hoof ◽  
...  

Twenty Gram-negative, rod-shaped, slightly curved, non-spore-forming bacteria that gave a negative result in Arcobacter species-specific PCR tests but that yielded an amplicon in an Arcobacter genus-specific PCR test were isolated from 13 unrelated broiler carcasses. Numerical analysis of the profiles obtained by SDS-PAGE of whole-cell proteins clustered all isolates in a single group distinct from the other Arcobacter species. DNA–DNA hybridization among four representative strains exhibited DNA binding values above 91 %. DNA–DNA hybridization with reference strains of the current four Arcobacter species revealed binding levels below 47 %. The G+C contents ranged between 26·8 and 27·3 mol%. Pairwise comparison of 16S rRNA gene sequences revealed the mean values for similarity to the type strain of Arcobacter cryaerophilus (97·5 %), Arcobacter butzleri (96·5 %), Arcobacter skirrowii (96·0 %) and Arcobacter nitrofigilis (95·0 %). The levels of similarity to Campylobacter and Helicobacter species were below 88 and 87 %, respectively. The isolates could be distinguished from other Arcobacter species by the following biochemical tests: catalase, oxidase and urease activities; reduction of nitrate; growth at 25 and 37 °C under aerobic conditions; growth on 2–4 % (w/v) NaCl media; and susceptibility to cephalothin. These data demonstrate that the 20 isolates represent a single novel Arcobacter species, for which the name Arcobacter cibarius sp. nov. is proposed, with LMG 21996T (=CCUG 48482T) as the type strain.


2007 ◽  
Vol 5 (3) ◽  
pp. 375-383 ◽  
Author(s):  
Bram M. W. Diederen ◽  
Caroline M. A. de Jong ◽  
Ingrid Aarts ◽  
Marcel F. Peeters ◽  
Anneke van der Zee

Our aim was to investigate the occurrence and identity of Legionella spp. in Dutch tap water installations using culture, real-time PCR and sequence analysis. The PCR assays used were a 16S rRNA gene based PCR with both a Legionella species specific probe and a L. pneumophila specific probe and a L. pneumophila-specific PCR based on the sequence of the mip gene. A total of 357 water samples from 250 locations in The Netherlands was investigated. The detection rates of Legionella spp. were 2,2% (8 of 357) by culture, and 87,1% (311 of 357) by PCR. The majority of samples was found to contain Legionella species other than L. pneumophila. These comprised of Legionella Like Amoebal Pathogens (LLAPs), L. busanensis, L. worsliensis and others. Fourteen (3,9%) samples were positive for L. pneumophila by either culture, 16S rRNA based PCR and/or mip based PCR. It is apparent from this study that Legionella spp. DNA is ubiquitous in Dutch potable water samples. Our findings further suggest that LLAPs and viable but nonculturable (VBNC) Legionella represent a large proportion of the population in man-made environments.


2006 ◽  
Vol 69 (9) ◽  
pp. 2241-2247 ◽  
Author(s):  
JEONG CHUL HA ◽  
WAN TAE JUNG ◽  
YONG SUK NAM ◽  
TAE WHA MOON

To control the spread of bovine spongiform encephalopathy in cattle through contaminated animal feedstuffs, screening of feed products is essential. We designed five pairs of primers to identify specifically raw and heat-treated tissue from cattle, sheep, goat, deer, and ruminants in general. A forward common primer was designed based on a conserved DNA sequence in the mitochondrial 12S rRNA–tRNAval–16S rRNA gene, and reverse primers were designed to hybridize with a species-specific DNA sequence for each species considered. All primers were developed to create a specific PCR product small enough (less than 200 bp) to be suitable for heat-treated material. To evaluate the effect of heat treatment, a severe sterilization condition (133°C at 300 kPa for 20 min) was chosen. Species-specific amplicons were obtained from all types of heat-treated meat meals. Analysis of laboratory-contaminated vegetable meals revealed that the detection limit of the assay was 0.05% for each species analyzed. This PCR-based analysis can be used as a routine method for detecting banned animal-derived ingredients in raw and heat-treated feedstuffs.


2000 ◽  
Vol 38 (8) ◽  
pp. 2962-2965 ◽  
Author(s):  
Paul W. Whitby ◽  
Karen B. Carter ◽  
Kenneth L. Hatter ◽  
John J. LiPuma ◽  
Terrence L. Stull

Definitive identification of the species in the Burkholderia cepacia complex by routine clinical microbiology methods is difficult. Phenotypic tests to identify B. multivorans andB. vietnamiensis have been established; more recent work indicates B. stabilis may also be identified by growth characteristics and biochemical tests. However, attempts to identify genomovars I and III have, thus far, proved unsuccessful. Previously, we demonstrated the utility of two primer pairs, directed to the rRNA operon, to specifically identify the B. cepacia complex in a PCR. One of these primer pairs, G1-G2, only amplified a DNA fragment from genomovars I and III and B. stabilis in a PCR with genomic DNA isolated from prototypical strains representing the five genomovars. Sequence analysis of the rRNA operon for all the genomovars indicated that this primer pair targeted a region shared by these isolates. Further analysis revealed a region of heterogeneity between genomovar III and B. stabilis internal to the amplified product of G1-G2. Primers designed to target this region were tested with prototypical strains following an initial amplification with the G1-G2 primer pair. New primers specific for the prototypical genomovar III and B. stabilis were designated SPR3 and SPR4, respectively. Analysis of 93 isolates representing 18 genomovar I, 13B. multivorans, 36 genomovar III, 11 B. stabilis, and 15 B. vietnamiensis isolates was performed. DNA from all isolates of genomovars I and III and B. stabilis was amplified by G1-G2. Genomovar III isolates yielded a product with SPR3/G1 while B. stabilis amplified with SPR4-G1. Genomovar I isolates were amplified by either SPR3-G1 or SPR4-G1, but not both. B. multivorans yielded a product with SPR3-G1 but not G1-G2, and B. vietnamiensis isolates were negative in all PCRs. Thus using an algorithm with G1-G2, SPR3-G1, and SPR4-G1 primers in a PCR analysis, genomovar III isolates can be separated from B. stabilis and the identity of B. multivorans and B. vietnamiensis can be confirmed.


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