Isolation and identification of nitrifying bacteria from tilapia (Oreochromis sp.) pond in Sleman Yogyakarta Indonesia

This research aims to isolate and identify autochtonous nitrifying bacteria from tilapia pond in Sleman Yogyakarta Indonesia for future application in aquaculture practices in the region. Bacteria were isolated using a nitrification medium. Bacterial characterization was carried out by non-pathogenic test to tilapia (Oreochromis sp.), and nitrification activity test in a single bacterial fermentation medium for 9 days. Bacterial identification was carried out based on the colony and cell morphologies, biochemical tests, and molecular analysis using the 16S rRNA and gyrB genes. A total of 15 isolates of nitrifying bacteria were obtained. Four non-pathogenic isolates obtained the highest nitrification activity on the sixth day of incubation, with nitrate production of 17.26-21.54 ppm. Two selected bacteria, isolates A2 and A3, have colony morphology that is milky white, smooth surface, circular shape, entire edge, and convex elevation. Both bacteria are short rods, Gram-negative, non-motile, produce catalase, fermenting glucose, sucrose, and lactose, and do not produce oxidase, ornithine decarboxylase, indole, and H2S. Molecular analysis showed that the two isolates had the highest similarity (99.28% and 99.34%) to Klebsiella spp.

Bacterias multirresistentes en Centros de Cuidado de niños

Purpose:To describe the antibiotic resistance of isolated bacteria on the surfaces of child care centers. Methods:Swabs were used to sample the surfaces in 266 child care centers in Bogotá (Colombia). Bacterial characterization and susceptibility patterns were verified using a computerized system. Results:A total of 151 different bacteria were obtained, primarily in the kitchens (36%). Staphylococcuswas a frequent find, especially: S. hominis, S. saprophyticusand S. epidermidis;2.7% were resistant to methicillin. Klebsiella oxytocawas the most isolated bacteria in kitchens, with high resistance to antibiotics. Conclusion:This investigation shows the importance of identifying the bacteria present in different environments to which children are exposed to continuously supervise hygiene habits in child day care centers.

Bacterial Pneumonia Co-Infection in COVID-19 Patients

The objective of this study was to highlight the emergence of COVID-19 bacteria pneumonia co-infections in patients infected with SARS-Cov-2 and risk factors related to its incidence and outcomes. We reported two cases of elderly patients with multiple comorbidities infected with SARS-Cov-2 and developed COVID-19 bacterial pneumonia requiring admission to intensive care unit (ICU) with one mortality preceded by septicemic shock and multi-organ failures. Observing the potential risk factors for being infected with SARS-Cov-2 and developing COVID-19 bacterial pneumonia we strongly advocate for rapid detection of COVID-19 bacterial pneumonia in SARS-Cov-2 infected patients and rapidly characterized the bacterial involved for a better outcome and importantly for efficient antimicrobial stewardship. COVID-19 bacterial pneumonia is an emerging disease requiring rapid detection and bacterial characterization with the ongoing management for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 Keywords: COVID-19, bacterial pneumonia, acute respiratory syndrome

Systematic review of descriptions of novel bacterial species: evaluation of the twenty-first century taxonomy through text mining

Although described bacterial species increased in the twenty-first century, they correspond to a tiny fraction of the actual number of species living on our planet. The volume of textual data of these descriptions constitutes valuable information for revealing trends that in turn could support strategies for improvement of bacterial taxonomy. In this study, a text mining approach was used to generate bibliometric data to verify the state-of-art of bacterial taxonomy. Around 9700 abstracts of bacterial classification containing the expression ‘sp. nov.’ and published between 2001 and 2018 were downloaded from PubMed and analysed. Most articles were from PR China and the Republic of Korea, and published in the International Journal of Systematic and Evolutionary Microbiology. From about 10 800 species names detected, 93.33 % were considered valid according to the rules of the Bacterial Code, and they corresponded to 82.98 % of the total number of species validated between 2001 and 2018. Streptomyces , Bacillus and Paenibacillus each had more than 200 species described in the period. However, almost 40 % of all species were from the phylum Proteobacteria . Most bacteria were Gram-stain-negative, bacilli and isolated from soil. Thirteen species and one genus homonyms were found. With respect to methodologies of bacterial characterization, the use of terms related to 16S rRNA and polar lipids increased along these years, and terms related to genome metrics only began to appear from 2009 onward, although at a relatively lower frequency. Bacterial taxonomy is known as a conservative discipline, but it gradually changed in terms of players and practices. With the advent of the mandatory use of genomic analyses for species description, we are probably witnessing a turning point in the evolution of bacterial taxonomy.

A CURE for physiological characterization of bacterioplankton in liquid culture

ABSTRACTBacterial characterization is an important aspect of microbiology that includes experimentally determining growth rates, environmental conditions conducive to growth, and the types of energy sources microorganisms can use. Researchers use this information to help understand and predict an organism’s ecological distribution and environmental functions. Microbiology students generally conduct bacterial characterization experiments in their coursework; however they are frequently restricted to model organisms without ecological relevance and for which the results have been known for decades. We present a course-based undergraduate research experience (CURE) curriculum to involve students in characterization of previously untested, ecologically relevant bacterioplankton cultures to identify the carbon substrates used for growth, as well as the temperature and salinity ranges conducive to growth. Students use these results to connect their organism’s physiology to the isolation environment. This curriculum also exposes students to advanced microbiology methods such as flow cytometry for measuring cell concentrations, teaches them to use the programming language R for data plotting, and emphasizes scientific communication through writing, speaking, poster creation/presentation, and social media. This CURE is an attractive introduction to scientific research and was successfully tested with 147 students during the fall semester of 2018.

Treatment of Low Biodegradability Leachates in a Serial System of Aged Refuse-Filled Bioreactors

This paper presents a technology based on the use of aged refuse that has proven to be highly effective in the treatment of low biodegradability leachates. The tests were developed using two filled bioreactors arranged in series and operated at steady state. The aged refuse used as filling material was extracted from a city located in the southeast of Mexico and characterized by particle size, humidity, volatile solids, and volumetric weight. On the other hand, bacterial characterization made it possible to identify the presence of species related to the degradation and mineralization of organic compounds, as well as to processes of nitrification or reduction of phosphates and Cr (VI). The bioreactor system was operated under four hydraulic loads (10, 20, 35, and 50 L/m3·d). Maximum removal efficiencies of 85, 86.1, 87.9, 98.6, 97.8, and 97.4% were achieved in COD, BOD5, Color, TP, TN, and N-NH3, respectively, complying with Mexican regulations (NOM-001-SEMARNAT-1996). The system also proved to be stable against shock loads, such as organic load fluctuations in the influent or pH variations. The results of this study show that, in countries such as Mexico, aged refuse extracted from landfills represents a promising option as a sustainable alternative for leachate treatment.