Detection Of Bacterial Species Research Articles

Lectin-Modified Bacterial Cellulose Nanocrystals Decorated with Au Nanoparticles for Selective Detection of Bacteria Using Surface-Enhanced Raman Scattering Coupled with Machine Learning

Bacterial cellulose nanocrystals (BCNCs) are tunable and biocompatible cellulose nanomaterials that can be easily bioconjugated and used for biosensing applications. We report the application of concanavalin A (con A) lectin-modified BCNCs (con A + BCNCs) for bacterial isolation and label-free surface-enhanced Raman spectroscopy (SERS) detection of bacterial species using Au nanoparticles (AuNPs). The aggregated AuNP + bacteria + (con A + BCNC) conjugates generated SERS hot spots that enabled the SERS detection of the strain Escherichia coli 8739 at the 103 CFU/mL level. The optimized detection assay was then used to differentiate 19 common bacterial strains. The large SERS spectral dataset for the 19 bacterial strains was analyzed using the support vector machine (SVM), an optimization-based machine-learning technique that worked as a binary classifier. The SVM classifier showed a high overall accuracy of 87.7% in correctly discriminating bacterial strains. This study illustrates the potential of combining low-cost nanocellulose-based SERS biosensors with machine-learning techniques for the analysis of large spectral datasets.

Evaluation of 16S rRNA Hypervariable Regions for Bioweapon Species Detection by Massively Parallel Sequencing.

Molecular detection and classification of the bacterial groups in a sample are relevant in several areas, including medical research and forensics. Sanger sequencing of the 16S rRNA gene is considered the gold standard for microbial phylogenetic analysis. However, the development of massively parallel sequencing (MPS) offers enhanced sensitivity and specificity for microbiological analyses. In addition, 16S rRNA target amplification followed by MPS facilitates the combined use of multiple markers/regions, better discrimination of sample background, and higher sample throughput. We designed a novel set of 16S rRNA gene primers for detection of bacterial species associated with clinical, bioweapon, and biohazards microorganisms via alignment of 364 sequences representing 19 bacterial species and strains relevant to medical and forensics applications. In silico results indicated that the hypervariable regions (V1V2), (V4V5), and (V6V7V8) support the resolution of a selected group of bacteria. Interspecies and intraspecies comparisons showed 74.23%–85.51% and 94.48%–99.98% sequencing variation among species and strains, respectively. Sequence reads from a simulated scenario of bacterial species mapped to each of the three hypervariable regions of the respective species with different affinities. The minimum limit of detection was achieved using two different MPS platforms. This protocol can be used to detect or monitor as low as 2,000 genome equivalents of bacterial species associated with clinical, bioweapon, and biohazard microorganisms and potentially can distinguish natural outbreaks of pathogenic microorganisms from those occurring by intentional release.

Detection of bacterial species in the Sequestra of Bisphosphonate-Related Osteonecrosis of the Jaws

Detection of bacterial species in the Sequestra of Bisphosphonate-Related Osteonecrosis of the Jaws

Intrauterine Bacterial Colonization and Endometrial MicroRNA-17-5p Levels in Association to Endometriosis: A Study in an Egyptian Population

ABSTRACT We aimed to study the relation between both bacterial colonization of the uterine endometrium & endometrial miR-17-5p levels and endometriosis, and then to evaluate endometrial miR-17-5p as a biomarker of endometriosis. A comparative observational study was carried over 51 endometriosis patients and 51 controls admitted into Obstetrics and Gynecology department, Mansoura Faculty of Medicine. Endometrial tissue samples were collected and aimed for bacterial culture and identification of resulting organisms besides estimation of tissue levels of microRNA-17-5p by quantitative real time PCR. G. vaginalis, S. agalactiae, S. aureus, Mobiluncus and E. coli were associated with endometriosis. MicroRNA-17-5p was up-regulated in endometriosis patients (P value was <0.0001*). Its sensitivity and specificity were 90% and 76.5%. MiR-17-5p showed higher results in culture positive than negative cases. On studying the relation between the positivity of endometrial tissue culture and miR-17-5p and so endometriosis, P value was <0.0001*. We concluded that G. vaginalis, S. agalactiae, S. aureus, Mobiluncus and E. coli were associated with development of endometriosis. Endometrial miR-17-5p was elevated in association to positive detection of bacterial species. MiR-17-5p might be a bio- marker of endometriosis. Abbreviations CFU/ml: Colony Forming Unit per Milliliter; miR-17-5p: MicroRNA-17-5p; qRT PCR: Quantitative Real Time Polymerase Chain Reaction.

Detection of bacterial species from clinical mastitis in dairy cows at Nilphamari district and their antibiogram studies

The present study was conducted on the rural dairy cows to detect the bacterial species from clinical mastitis in dairy cows with their antibiogram studies during the period from January 2015 to June 2015. For this purpose two upazilla were selected under the Nilphamari district. On the basis of morphology, staining, cultural and biochemical characteristics, the isolated organisms were classified as, Staphylococcus spp., Streptococcus spp., E. coli, and Bacillus spp. .For this study, a total of 48 samples were collected from affected mastitis cows. Out of 48 milk samples, 17 were positive for Staphylococcus spp. (35.42%), 9 were positive for Streptococcus spp. (18.75%), 7 were positive for E. coli (14.58%), 5 were positive for Bacillus spp.(10.41%),5 were positive for mixed organisms (10.41%) and 5 were unidentified organisms (10.41%). Antibiogram studies revealed that all of the isolates of Staphylococcus spp. were sensitive to gentamicin and were resistant to streptomycin. Gentamicin was sensitive to all of the isolates of Streptococcus spp. and was resistant to streptomycin. The isolates of Bacillus spp. were sensitive to ciprofloxacin and Bacillus spp. was resistant to streptomycin. All of the isolates of E. coli were sensitive to ciprofloxacin the isolates were resistant to ampicillin and amoxicillin. Over all sensitivity revealed that ciprofloxacin, gentamicin and enrofloxacin were most efficacious. Thus, it may be recommended that ciprofloxacin, gentamicin and enrofloxacin in optimum doses would resolve most cases of clinical mastitis in dairy cows.Asian J. Med. Biol. Res. December 2016, 2(4): 656-663

Detection of Bacterial Species in Chronic Periodontitis Tissues at Different Stages of Disease Severity

The goal of this research was to determine the relationship between the stage of chronic periodontitis and the presence of six bacterial pathogens (Aggregatibacter actinomycetemcomitans: AA, Fusobacterium nucleatum: FN, Porphyromonas gingivalis: PG, Prevotella intermedia: PI, Enterococcus faecalis: EF, and Parvimonas micra: PM). Forty-six chronic periodontitis patients visiting a dental hospital were included in this investigation. They were classified into four chronic periodontitis stages based on the sulcus bleeding index value and the probing depth. The tissue samples from the periodontal surgery were used for a direct PCR detection assay. A total of 49 samples from 46 patients were collected and classified into four chronic periodontitis groups (N: 6, P1: 13, P2: 18, P3: 12). The PCR assay showed that FN, PI, and PM were involved from the beginning of chronic periodontitis (P1), while AA and PG existed regardless of the disease stages. EF was strongly linked to the P3 stage of the disease. In order to assess the effect of dental treatments on patients with chronic periodontitis, EF should be a critical marker for P3 patients, while FN, PI, and PM would be good indicators for chronic periodontitis.

Assessment of Association between Schizophrenia and Chlamydiaceae Using Hill Criteria

Schizophrenia is a complex chronic neuropsychiatric disorder of the central nervous system with worldwide prevalence. The disease is thought to have multiple etiologies, including infections, genetic predisposition, and other environmental factors. There is increasing evidence pointing to a close association between chlamydial infections and schizophrenia. Here, we review the data available in the literature on the detection of bacterial species in the family Chlamydiaceae in schizophrenia and critically analyze the association and causal relationship between Chlamydiaceae and schizophrenia following the established criteria of Hill. This analysis demonstrates a probable causal relationship between Chlamydiaceae and schizophrenia. The identification of microbial agents associated with the etiopathogenesis of schizophrenia may provide new insight into the diagnosis, treatment and prevention of the disorder.

넙치(Paralichthys olivaceus) 성어의 viral hemorrhagic septicemia (VHS) 진단사례

We examined the cause of a disease outbreak in adult olive flounder Paralichthys olivaceus, which occurred at a Korean aquaculture farm in Korea in 2011. The principal signs included an expanded abdomen and congested liver, with persistent mortality (a little over two months). At the beginning of the outbreak, farm administrators misjudged the disease as bacterial in origin, because of the aforementioned signs, persistent mortality, and the detection of bacterial species, including Vibrio spp. and Streptococcus spp. Moreover, the detection of viral hemorrhagic septicemia virus (VHSV) by reverse trasnscription-PCR analysis was complicated by use of the VHS-VN primer set, which has been in general use recently, because it produced weak bands in some samples. Therefore, we recommend the use of at least two different primer sets in the diagnosis of VHSV. Our histopathological findings indicate that necrotizing myocarditis could be considered a pathogenic sign of VHSV infection.

Spoilage-related microbiota associated with chilled beef stored in air or vacuum pack

In order to study the spoilage-related microbiota of beef at species level, a combination of culture-independent and culture-dependent methods was used to analyse nine different beef samples stored at 4 °C in air or in vacuum pack. Plate counts on selective agars after 0, 7 and 20 days of storage showed that vacuum packaging reduced the viable counts of Brochothrix thermosphacta, Pseudomonas spp. and Enterobacteriaceae, whereas the growth of lactic acid bacteria (LAB) was unaffected. Storage in vacuum pack mainly affected viable counts and not necessarily the species diversity of microbial populations on meat. Such populations were studied by PCR-DGGE of DNA directly extracted from meat and from bulk cells from culture media, followed by sequencing of DGGE fragments. Pseudomonas spp., Carnobacterium divergens, B. thermosphacta, Rahnella spp. and Serratia grimesii, or close relatives were detected in the meat at time zero. The use of the culture-independent method highlighted the occurrence of species that were not detected by plating. Photobacterium spp. occurred in most meat samples stored in air or in vacuum pack, which indicates this organism probably has a role in spoilage. In contrast, culture-dependent analysis allowed detection of bacterial species that were not found in DNA extracted directly from meat. This was the case for several species of Serratia or Rhanella among the enterobacteria, and Leuconostoc spp. among the LAB. Besides advancing our knowledge of the species involved in the spoilage of vacuum-packaged meat, this study shows the benefits of combining culture-based and direct approaches to enhance understanding of populations of spoilage bacteria.

Detection of Helicobacter pylori, Enterococcus faecalis, and Pseudomonas aeruginosa in the subgingival biofilm of HIV-infected subjects undergoing HAART with chronic periodontitis

This study compared the frequency of Helicobacter pylori, Enterococcus faecalis, and Pseudomonas aeruginosa in the subgingival microbiota of HIV-seropositive and HIV-seronegative subjects with periodontitis or clinically healthy periodontal tissues. Fifty-four subjects were distributed into two HIV-seropositive groups (chronic periodontitis [HCP = 13] and periodontal health [HH = 10]) and two HIV-seronegative groups (chronic periodontitis [CP = 17] and periodontal health [H = 14]). The detection of bacterial species was carried out by polymerase chain reaction (PCR). CP patients showed significantly more periodontal destruction, inflammation, and supragingival plaque than HCP patients (P < 0.05). All species were detected at a higher prevalence in CP and HCP than H individuals (P < 0.01). In the HIV groups, H. pylori was significantly more prevalent in periodontitis compared to healthy patients (P < 0.01). A higher frequency of E. faecalis and P. aeruginosa was observed in the subgingival biofilm of HH than H subjects (P < 0.01). Moreover, E. faecalis was detected significantly more often in HIV-seropositive compared to HIV-seronegative patients, regardless of periodontal status (P < 0.01). These data indicate that H. pylori is frequently detected in the subgingival microbiota of periodontitis subjects. In contrast, HIV-seropositive patients with either periodontitis or periodontal health present a high prevalence of E. faecalis.

P1548 Rapid molecular detection of bacterial species and resistance determination in paediatric blood cultures

P1548 Rapid molecular detection of bacterial species and resistance determination in paediatric blood cultures