Applied Microbiology: Theory ＆ Technology

Historical Perspectives of SARS-CoV-2 Viral Subversion of Host Cell: Biochemical and Pathological Aspects

Riham Abdel Hamid Haroun — 2023-12-21

The pandemic of coronavirus disease-19 (COVID-19) was a worldwide health crisis affecting many more people than 221 countries causing life-threatening complications and indirectly affecting even more individuals through disruption of daily living. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is a member of beta-coronavirus having RNA as a genetic material sharing 79% similarity with the bat SARS-CoV genome. The SARS-CoV-2 enters the host cells by binding specifically to the angiotensin-converting enzyme-2 (ACE-2) which is expressed on the surface of epithelial cells in the respiratory tract, intestine, kidneys, and others causing severe acute respiratory failure and other complications. In addition to respiratory symptoms, uncontrolled SARS-CoV-2 infection can induce a cytokine storm, whereby pro-inflammatory cytokines and chemokines such as IL-6, TNF-α, and IL-1β are increased, which in turn leads to multiorgan damage. Herein, we described the history and classification of coronaviruses, geographical distribution of COVID-19, SARS-CoV-2 structure and genomic organization, life cycle, immunopathological responses, symptoms, and finally pulmonary and extra-pulmonary complications of SARS-CoV-2 infection.

Total Laboratory Automation in Clinical Microbiology: A Note on Needs, Challenges, and Applications in a Pandemic Scenario

Priyadarshi Soumyaranjan Sahu — 2024-04-01

Recently, an increasing number of publications on automation in diagnostic laboratories, especially in microbiology, has illustrated its potential impact on modern medicine by enhancing the overall quality of culture-based microbiology testing. In the context of clinical microbiology, total laboratory automation (TLA) is now defined as automating the testing workflow, which comprises all phases from sample inoculation to outcome analysis. Hence, there is a need to design or implement proper laboratory automation management processes to enhance workflow, reduce analysis time, and deliver high-quality results without delay in treatment initiation. This review-cum-perspective article highlights the need and current advancements in diagnostic microbiology automation that could revolutionize laboratory operations in healthcare settings. Automation of the workflow is a crucial advancement in the recent history of laboratory diagnostics that unites many diagnostic specializations into a single track to increase the effectiveness, administration, standardization, reliability, and safety of lab tests. While clinical chemistry laboratories adopted and deployed laboratory automation decades earlier, the process of implementing them into routine clinical microbiological practices has several bottlenecks and is still a lengthy process and fraught with technical and regulatory challenges. Moreover, due to outbreaks including the COVID-19 pandemic of recent times, testing volumes are increasing, and automation could probably be a great solution for small and mid-sized laboratories. This article lists the TLA remedies and the specimen-processing tools that are presently available. The need and challenges to implementing automation in microbiological laboratories are discussed with a note on applications in pandemic scenarios.

Significant Role of Plant Growth Promoting Rhizobacteria in Agriculture Field

Suraj Kumar Gupta — 2023-12-19

Rapid population growth in the modern era has been associated with serious problems in the worldwide agro-ecosystems, which have resulted in lower production and a degradation of sustainable agro-ecosystems. Phytomicrobiome is one of the most effective methods, a superior option for agricultural sustainability and resolving both the issues of sustainability in the environment and worldwide food security. Plant growth-promoting rhizobacteria (PGPR) are free-living soil bacteria that may have both direct and indirect impacts on the growth of plants. The metabolism of plants can be significantly affected by bacteria that support the growth of plants and utilize their own metabolic pathway to dissolve phosphates, fix nitrogen, and develop hormones. Plant-beneficial rhizobacteria may reduce the world’s dependency on dangerous chemicals for agriculture that disrupt agroecosystems. PGPR provides farmers with a great alternative to lowering their use of artificial pesticides and fertilizers without having a negative impact on the environment or reducing crop yields. The use of PGPR as formulations or bioinoculants is a very efficient technique to increase agricultural productivity in a sustainable manner. This review enhances the perception of the PGPR, relevant outlooks on the various mechanisms of rhizobacteria-mediated promotion of plant growth have been explained in detail with recent research.

Efficient Screening and Enhanced Exopolysaccharide Production by Functional Lactic Acid Bacteria (LAB) in Lactose Supplemented Media

Ana I. E. Pintado — 2024-01-17

Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) can be considered as natural biological thickeners that have attracted considerable attention in the food industry. This study aimed to evaluate and select potentially EPS-producing strains LAB and to assess the influence of carbon source and aeration on EPS production. Nine LAB strains were assessed as potential EPS producers, and Rahnella aquatilis ATCC 55046 was employed as the positive control strain for EPS. The compaction test and the observation of viscous colonies in a solid medium did not yield sufficient evidence for the presence of EPS. The assessment of capsules through staining provided evidence of EPS presence only for Rahnella aquatilis ATCC 55046. The EPS yield was subsequently assessed in De-Man Rogosa and Sharpe (MRS) broth medium supplemented with 2% (w/w) fructose (MRS-f) or lactose (MRS-l), as well as in whey (Whey) and whey supplemented with 2% (w/w) lactose (Whey-l). The EPS production in the various culture media under study ranged from 194 to 1,187 mg of EPS/g of polymer dry mass (PDM). These results suggest that the culture medium and carbon sources had an impact on the EPS production of the different strains. Bifidobacterium animalisBb12 achieved the highest EPS production in MRS-f. In the case of MRS-l, the control strain recorded the highest EPS value, along with Lactobacillus acidophilus LAC-1. Regarding Whey, Lentilactobacillus Kefir NCFB 2753 exhibited the highest EPS production, while in Whey-l, Lacticaseibacillus paracasei LCS-1 emerged as the top performer in terms of EPS production. This suggests that certain strains exhibit potential for use in the production of novel fermented EPS products, whether dairy or non-dairy.

Characteristics of Enterococcus Faecalis in Periodontitis and Secondary Root Canal Infections in Northern Jordanians-A Pilot Study

Rola Al Habashneh — 2024-03-07

Background: Enterococcus faecalis has been found to be related to periodontitis and secondary endodontic infections. In this study, we aimed to study samples of E. faecalis to determine their incidence and virulence in Jordanian patients. Methods: A total of 167 samples were collected from patients with periodontitis and secondary endodontic infections. The Kirby-Bauer method was used to determine the antimicrobial susceptibility. Biofilm formation was studied using the microtiter plate assay and congo red agar assay. Polymerase chain reaction (PCR) was used to detect the presence of E. faecalis virulence genes, namely; asa1, gelE, cylA, esp, hyl, efaA, and ace. Gelatinase and cytolysin activity were also tested using phenotypic methods. Results: Twenty-three (13.8%) samples were positive for E. faecalis. The highest resistance rates were observed against ampicillin (87%), followed by penicillin (82.6%), and erythromycin (60.9%). The highest susceptibility was for levofloxacin (100%), followed by gentamycin and chloramphenicol, each with 95.7%. Most isolates were able to produce biofilm (78.3%). Gelatinase and cytolysin activity were detected in 21.7% and 56.5% of isolates, respectively. efaA was significantly associated with asa1 and gelE (P < 0.05), and esp was significantly associated with cylA, gelE, ace, efaA and asa1 ( P < 0.05). In addition, the gelE. gene was significantly associated with gelatinase production (P < 0.01). Conclusion: In conclusion, we have shown that E. faecalis is involved with periodontal disease and secondary root canal infection with several virulence genes detected. Clinical Relevance: Around 13% of the periodontitis and secondary root canal infection patients were positive for E. faecalis and isolates were resistant to commonly used antibiotics.