Large Variety Of Microorganisms Research Articles

Establishment of a Single Temperature Incubation Approach for Environmental Monitoring Samples with Focus on Mold Recoveries.

A robust environmental monitoring program is essential to properly estimate and identify microorganisms in cleanrooms, ensuring that microbial contamination remains acceptably low, and a good state of control is maintained in the manufacturing areas. The incubation conditions are important to support optimal microbial recoveries, considering that there is no single culture medium, temperature and incubation time that can recover all microorganisms. Particularly molds are quite sensitive microorganisms, and some species may have very specific nutritional and environmental needs. In this study, a two-phase approach was used to identify a single incubation-temperature approach that could recover most of the cleanroom microbial flora with focus on molds. Phase 1 included a growth promotion study performed in the laboratory using pharmacopeial and in-house strains, comparing different media (SDA and TSA) at single or dual incubation-temperature approaches for 5 or 6 days. Phase 2 was based on an in situ study where sampling was performed in different areas of a pharmaceutical facility, comparing the recoveries at different incubation conditions. In addition, extension studies of phase 1 and phase 2 were performed to get a better understanding of growth requirements for in-house molds. The results show that an incubation on Tryptone Soy Agar (TSA) at 25-30° for 3-4 days was able to recover most tested microorganisms in phase 1 and a large variety of microorganisms in phase 2, indicating that the single incubation-temperature is an optimal approach for the recovery of microorganisms in cleanrooms. Exceptions were noted for one strain of the species Cutibacterium acnes, a microaerophilic bacterium for which anaerobiosis and higher temperatures were needed, and two mold strains (Sistotrema brinkmannii and Stereum hirsutum), indicating that those molds required a specific media (Sabouraud Dextrose Agar, SDA) for their proliferation. The results showed that TSA incubated at single or dual incubation-temperature approach cannot compensate for the absence of SDA for some environmental molds that may be atypical in cleanrooms. Therefore, in addition to TSA, certain monitoring with SDA at e.g., cleanroom entrance points may be beneficial to recover molds with very specific nutritional requirements.

Isolation, identification and conservation of bacteria of biotechnological interest

Introduction. The evaluation of microbial biodiversity is an important step in the process of its conservation, and the identification of bacterial strains of biotechnological interest allows their application as support for the development of sustainable agriculture technologies.
 Material and methods. From the lakes of the "La Izvor" park, 213 types of bacteria, 148 of them pathogenic, were isolated. From the non-pathogenic ones, those of biotechnological interest were determined the enzymatic properties, antimicrobial activity and were identified by molecular biological methods after that preserved by the lyophilization method with the determination of viability before and after lyophilization.
 Results. The microbial biodiversity of the "La Izvor" lakes was studied, 213 types of bacterial colonies were isolated in pure culture, which of 148 proved to be enteropathogenic belonging to the genera Escherichia, Salmonella, Shigella, Enterobacter and Klebsiella as and other strains from the Enterobacteriaceae family. The purpose of the research consisted in the isolation and identification of non-pathogenic bacteria of biotechnological interest with different properties that could serve to elaborate and improve the development of sustainable agriculture technologies. Nineteen strains with enzymatic properties and high antifungal activity against phytopathogenic fungi, were selected for molecular identification, passported, submitted to the NCNM and preserved by the lyophilization method for determination valuable properties for a long time.
 Conclusions. In the lakes of "La Izvor" park there is a very large variety of microorganisms, especially bacteria, some of which are enteropathogenic bacteria that can cause diseases in the population. Selected non-pathogenic strains stored in the NCNM can be applied against phytopathogens that cause dangerous disease and damage in agriculture major crops. As a result of lyophilization, we found that all strains showed the osmotic and thermal shocks tolerance and have a viability over 75%.
 Key words: microbial biodiversity, isolation, identification, conservation.

Advances in pathogen diagnosis of respiratory infection diseases in 2021

Respiratory tract infections (RTI) are a common and highly prevalent disease in the population, which can develop into acute respiratory distress syndrome (ARDS) in severe cases.A large variety of microorganisms can cause RTI, including bacteria, respiratory viruses, and fungi. The timely and accurate detection of these pathogens is the prerequisites of effective treatment of RTI. However, more than 50% of RTI patients failed to diagnosis of causative agents due to unavailability of qualified samples, antimicrobial treatment prior to sample collection, high variety of respiratory pathogens, and influence of the normal flora in respiratory tract. In recent years, progress on molecular diagnosis, especially the novel approaches such as clinical metagenomics and CRSIPR (Clustered regularly interspaced short palindromic repeats), has not only improved our capacity for RTI pathogen detection but also brought new challenges. In this review, we summed up the advances in RTI pathogen diagnosis in 2021 and discussed the clinical benefits and challenges from novel approaches, which provided a clinical perspective on the development and application of these diagnostic tools in the real world.

Microflora of autopsy material from HIV-infected patients

According to literature, lungs are affected in 25 – 60% of HIV-infected individuals. The most common opportunistic disease in this group of patients is pneumonia of various etiology. HIV-positive patients show a wide microbiological landscape of pneumonia pathogens.The aim of the study was to determine the structure of the microflora of autopsy material obtained from the lungs of HIV-infected patients.Methods. 83 samples of autopsy material from patients with HIV infection and 27 samples from HIV-negative patients were analyzed. The deceased were treated in the pulmonary departments of Samara with a diagnosis of community-acquired pneumonia. Due to the large variety of microorganisms recovered from the autopsy material, the microorganisms were divided into several groups: Enterobacteria, non-fermentative gram-negative bacteria, Enterococci, Staphylococci, Sterptococci, and Corynebacteria. The fungi were divided into two subgroups. The first included Candida spp., the second included other types of fungi. The tests for pneumocystis infection, Mycobacterium tuberculosis, and non-tuberculosis mycobacteria were not performed.Results. Enterobacteria were found in 39.2%, non-fermentative gram-negative bacteria – in 27.3% and Enterococci – in 19.6% of the HIV-infected patients. Staphylococcus spp. were found in 4.2%, and Corynebacteria and Streptococci in 0.7% of those patients. Candida spp. accounted for 6.3%, other fungi were found in 2.0% of cases. Enterobacteria and non-fermentative gram-negative bacteria were found in 26.2% of HIV-negative patients. Enterococcus spp. – 21.4%, Staphylococci – 7.1%, Streptococci – 2.4% of those patients. Candida spp. 16.7% were found in 16.7% of HIV-negative patients. Enterobacteria were found significantly more often in the autopsy material from HIV-infected patients. The study shows the high importance of gram-negative flora as a causative agent of infectious lesions of the lung tissue. At the same time, we statistically confirmed an increase in prevalence of Enterobacteria in HIV-positive patients. Although these pathogens are not always detected in the sputum from HIV-infected patients with bronchopulmonary disorders, they are detected only by autopsy examination of the lung tissue.Conclusion. Diagnosis and treatment of pneumonia in HIV-infected patients with severe immunodeficiency have a few specific features, such as increasing the frequency of sputum culture, reducing the number of errors at the preanalytical stage of collecting the biomaterial, ensuring proper conditions for its transportation to a bacteriological laboratory, improving the quality of analysis. The physicians should be aware of the possible detection of gram-negative flora as a causative agent of lung infections and the possible change of the causative agent.

Pneumonia.

Pneumonia is a common acute respiratory infection that affects the alveoli and distal airways; it is a major health problem and associated with high morbidity and short-term and long-term mortality in all age groups worldwide. Pneumonia is broadly divided into community-acquired pneumonia or hospital-acquired pneumonia. A large variety of microorganisms can cause pneumonia, including bacteria, respiratory viruses and fungi, and there are great geographical variations in their prevalence. Pneumonia occurs more commonly in susceptible individuals, including children of <5 years of age and older adults with prior chronic conditions. Development of the disease largely depends on the host immune response, with pathogen characteristics having a less prominent role. Individuals with pneumonia often present with respiratory and systemic symptoms, and diagnosis is based on both clinical presentation and radiological findings. It is crucial to identify the causative pathogens, as delayed and inadequate antimicrobial therapy can lead to poor outcomes. New antibiotic and non-antibiotic therapies, in addition to rapid and accurate diagnostic tests that can detect pathogens and antibiotic resistance will improve the management of pneumonia.

Features of Biological Effects on Polymer Composite Materials in the Climatic Conditions of Yakutia

A large variety of microorganisms was isolated. It has been established that the soil cover and atmospheric air in the area of polygon climatic tests in the city of Yakutsk contain various types of microorganisms, including pathogenic species of mold fungi of the genus Aspergillus, which are highly likely to have biological agents of experimental samples. in contact with soil and atmospheric air in the landfill. What is confirmed by the results of microbiological studies.

Monitoring the Physiological State in the Dark Fermentation of Maize/Grass Silage Using Flow Cytometry and Electrooptic Polarizability Measurements

Dark fermentation (DF), a key biohydrogen-producing process, is generally operated as a black-box, by monitoring different operative macroscopic process parameters without evaluating or tracking the physiology of the biotic phase. The biotic phase in DF is constituted by a large variety of microorganisms, mainly fermentative bacteria. The present study uses two (electro)optical techniques, flow cytometry (FC) and frequency-dependent polarizability anisotropy (FDPA) measurements, to gain insights into the physiology of open mixed consortia throughout the DF process. The mixed consortia for DF were obtained from a methanogenic sludge, selecting spore-forming bacteria by means of an acid treatment. Then, DF systems with and without pH control were studied, using as substrate a mixture of maize and grass silage (9:1 w/w). Over the course of fermentation, the butyric pathway was dominant in both systems, and relevant titers of acetate, formate, and ethanol were detected; while hydrogen yields amounted to 20.80 ± 0.05 and 17.08 ± 0.05 NmL/gVS under pH-regulated and non-regulated conditions, respectively. The cytometric pattern analysis of the culture together with microscopic observations made it possible, over the course of fermentation, to identify and track the predominant morphologies in play (i.e., free spore, rod-shaped, and endospore, which are typical of Clostridium spp.). Furthermore, the use of the fluorescent dye DiBAC4(3) in FC and FDPA measurements provided similar information regarding the physiological state (PS) of the mixed consortia during the different phases of the culture.Graphical

Swarm Hunting and Cluster Ejections in Chemically Communicating Active Mixtures

A large variety of microorganisms produce molecules to communicate via complex signaling mechanisms such as quorum sensing and chemotaxis. The biological diversity is enormous, but synthetic inanimate colloidal microswimmers mimic microbiological communication (synthetic chemotaxis) and may be used to explore collective behaviour beyond the one-species limit in simpler setups. In this work we combine particle based and continuum simulations as well as linear stability analyses, and study a physical minimal model of two chemotactic species. We observed a rich phase diagram comprising a “hunting swarm phase”, where both species self-segregate and form swarms, pursuing, or hunting each other, and a “core-shell-cluster phase”, where one species forms a dense cluster, which is surrounded by a (fluctuating) corona of particles from the other species. Once formed, these clusters can dynamically eject their core such that the clusters almost turn inside out. These results exemplify a physical route to collective behaviours in microorganisms and active colloids, which are so-far known to occur only for comparatively large and complex animals like insects or crustaceans.

Metabolomics Study of Subsurface Wastewater Infiltration System Under Fluctuation of Organic Load.

Subsurface Wastewater Infiltration System (SWIS) is a sewage ecological treatment technology with low investment, energy consumption, and operating cost. SWIS soil contains a large variety of microorganisms. The metabolic process and production of microorganisms are an important basis for qualitatively describing the process of pollutant removal. In order to discover the microbial decontamination pathways in SWIS, the metabolic profiles of soil microorganisms in SWIS were analyzed by UPLC-MS. Partial least squares-discriminant analysis (PLS-DA)and principal component analysis (PCA) pattern recognition methods were used to classify the samples. According to the model's variable importance factor (VIP value), potential biomarkers were screened and biological information contained in the metabolites was also analyzed. The correlation between metabolites and environmental factors was explored by RDA analysis. In total, 230 differential metabolites with VIP value greater than 1.5 were screened out when the influent organic load fluctuated at 250mgL-1, 400mgL-1, and 500mgL-1. After identifying and screening, 35 differential metabolites were identified and used to further analyze the metabolic pathway. It turns out that microbial metabolites in SWIS were mainly glycosides, fatty acids, amino acids, pigments, diterpenoids, and some polymers under medium and high organic loading conditions. At low organic load, the microbial metabolites in SWIS were mainly ketones, alcohols, and esters.

Antimicrobial activities and in vitro properties of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes of high latitude water areas in Xinjiang, China

BackgroundThere are still a large variety of microorganisms among aquatic animals, especially probiotic lactic acid bacteria in cold water fishes at high latitudes have not been fully developed. Hence, the present study aims to evaluate the probiotic potential of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes (Xinjiang) and select candidates to be used as new food preservative agents and/or probiotic additives in feeding of aquaculture.ResultsA total of 43 Lactobacillus spp. were isolated from 16 kinds of intestinal tract of cold-water fishes. They were characterized by phenotypic methods, identified using Rep-PCR and 16S rRNA gene sequencing as four species: Lactobacillus sakei (22 isolates), Lactobacillus plantarum (16 isolates), Lactobacillus casei (4 isolates) and Lactobacillus paracasei (1 isolate). The in vitro tests included survival in low pH and bile, antimicrobial activity (against Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica, Listeria monocytogenes, and Listeria innocua), resistance to 15 antibiotics and hemolytic tests. Among all 43 lactobacilli isolates, the 22 isolates showed a wide range of antimicrobial activity against 6 different pathogenic strains. There were twenty isolates growing at optimal temperature ranging 16~20 °C, which were initially considered to be cold-adapted strains. Two (2) Lb. sakei strains and 2 Lb. plantarum strains demonstrated the highest survivability after 4 h of exposure at pH 2.0. Most of the tested strains cannot be cultured after exposed into 0.5% bile solution for 4 h, while 2 Lb. plantarum strains (E-HLM-3, CQ-CGC-2) and 1 Lb. sakei strain M-DGM-2 survived even at 2% bile concentration. In addition, the safety assessment showed that 22 strains without any detectable hemolytic activity and resistant to glycopeptides (vancomycin, teicoplanin), levofloxacin, aztreonam, amikacin and oxacillin, while all the studied lactobacilli showed sensitivity to or semi-tolerant to other antibiotics.ConclusionsBased on all the experiments, 3 strains, including E-HLM-3, CQ-CGC-2, and M-DGM-2 might be a candidate of choice for using in the food preservative agents and/or probiotic additives in feeding of aquaculture.

Chitosan-Stabilized Ag Nanoparticles with Superior Biocompatibility and Their Synergistic Antibacterial Effect in Mixtures with Essential Oils

Silver nanoparticles (AgNPs) are considered a promising alternative to the use of antibiotics in fighting multidrug-resistant pathogens. However, their use in medical application is hindered by the public concern regarding the toxicity of metallic nanoparticles. In this study, rationally designed AgNP were produced, in order to balance the antibacterial activity and toxicity. A facile, environmentally friendly synthesis was used for the electrochemical fabrication of AgNPs. Chitosan was employed as the capping agent, both for the stabilization and to improve the biocompatibility. Size, morphology, composition, capping layer, and stability of the synthesized nanoparticles were characterized. The in vitro biocompatibility and antimicrobial activities of AgNPs against common Gram-negative and Gram-positive bacteria were evaluated. The results revealed that chitosan-stabilized AgNPs were nontoxic to normal fibroblasts, even at high concentrations, compared to bare nanoparticles, while significant antibacterial activity was recorded. The silver colloidal dispersion was further mixed with essential oils (EO) to increase the biological activity. Synergistic effects at some AgNP–EO ratios were observed, as demonstrated by the fractionary inhibitory concentration values. Our results reveal that the synergistic action of both polymer-stabilized AgNPs and essential oils could provide a significant efficiency against a large variety of microorganisms, with minimal side effects.

Actividad esporicida de la solución electrolizada con ph neutro en hongos de importancia postcosecha

El agua electrolizada con pH neutro (7.0) es un novedoso agente antimicrobiano, que tiene efecto en una gran variedad de microorganismos, seguro para los seres humanos y el medio ambiente. Se determinó la eficacia del agua electrolizada de súper oxidación con pH neutro (SES) en la reducción de la germinación de esporas y desarrollo del tubo germinativo en hongos de importancia postcosecha. Una suspensión de 8X107esporas·mL-1 de los hongos Botrytis cinerea aislado de zarzamora, Colletotrichum gloeosporioides aislado de mango, guayaba y lichi, Fusarium solani aislado de chile y estevia, Monilinia fructicola aislado de durazno, Penicillium digitatum aislado de limón mexicano y limón persa, Penicillium sp. aislado de papaya y Rhizopus stolonifer aislado de yaca y guanábana, estuvieron en contacto con la SES por 5 minutos a concentraciones de 3, 5, 6, 8, 18, 24, 27, 29, 36 y 43 ppm de cloro libre, y agua destilada estéril (testigo). Las esporas se sembraron en medio de cultivo papa dextrosa agar (Bioxon®); las evaluaciones se realizaron a las 24 y 48 horas posteriores a la siembra. La inhibición del 100 % en la germinación de esporas y longitud del tubo germinativo de Botrytis se observó en el rango de concentración de 18-43 ppm, Colletotrichum (6-43 ppm), Fusarium (6-43 ppm), Monilinia (8 y 24-43 ppm), Penicillium (18-43 ppm), Rhizopus aislado de guanábana (5-24 y 29-43 ppm) y Rhizopus de yaca (18-43 ppm). Los resultados sugieren que la SES podría ser utilizada como alternativa de control de hongos postcosecha.&#x0D; &#x0D;

Oral ofloxacin and clindamycin as an alternative to the classic rifampicin–clindamycin in hidradenitis suppurativa: retrospective analysis of 65 patients

Rifampicin/Clindamycin (RC) combination is recommended as first line therapy in moderate to severe Hidradenitis Suppurativa (HS) by European S1 guidelines (1–3), notably because a large variety of microorganisms have been isolated from HS lesions: most represented bacteria appear to be Staphylococcus aureus, Coagulase negative staphylococci (CoNS) and anaerobic bacteria from normal skin flora. It has been hypothesized that these bacteria could play a central role in the initiation and maybe in the maintenance of HS lesions, possibly by being a source of antigens in a dysregulated immune response. This article is protected by copyright. All rights reserved.

Quorum-sensing in yeast and its potential in wine making

This mini-review synthesises the present knowledge of microbial quorum-sensing, with a specific focus on quorum-sensing in yeast, and especially in wine yeast. In vine and wine ecosystems, yeast co-interact with a large variety of microorganisms, thereby affecting the fermentation process and, consequently, the flavour of the wine. The precise connections between microbial interactions and quorum-sensing remain unclear, but we describe here how and when some species start to produce quorum-sensing molecules to synchronously adapt their collective behaviour to new conditions. In Saccharomyces cerevisiae, the quorum-sensing molecules were identified as 2-phenylethanol and tryptophol. However, it was recently shown that also a quorum-sensing molecule formerly identified only in Candida albicans, tyrosol, appears to be regulated in S. cerevisiae according to cell density. This review describes the methods for detection and quantification of those quorum-sensing molecules, their underlying mechanisms of action, and their genetic background. It also examines the external stimuli that evoke the quorum-sensing mechanism in the wine-processing environment. The review closes with insight into the biotechnological applications that are already making use of the advantages of quorum-sensing systems and indicates the important questions that still need to be addressed in future research into quorum-sensing.

Characterization and pharmacological potential of Lactobacillus sakei 1I1 isolated from fresh water fish Zacco koreanus.

BackgroundThere are still a large variety of microorganisms among aquatic animals which have not been explored for their pharmacological potential. Hence, present study was aimed to isolate and characterize a potent lactic acid bacterium from fresh water fish sample Zacco koreanus, and to confirm its pharmacological potential.MethodsIsolation of lactic acid bacteria (LAB) from fresh water fish samples was done using serial dilution method. Biochemical identification and molecular characterization of selected LAB isolate 1I1, based on its potent antimicrobial efficacy, was accomplished using API kit and 16S rRNA gene sequencing analysis. Further, 1I1 was assessed for α-glucosidase and tyrosinase inhibitory potential as well as antiviral efficacy against highly pathogenic human influenza virus H1N1 using MDCK cell line in terms of its pharmacological potential.ResultsHere, we first time report isolation as well as biochemical and molecular characterization of a lactic acid bacterium Lactobacillus sakei 1I1 isolated from the intestine of a fresh water fish Z. koreanus. As a result, L. sakei 1I1 exhibited potent antimicrobial effect in vitro, and diameter of zones of inhibition of 1I1 against the tested pathogens was found in the range of 13.32 ± 0.51 to 23.16 ± 0.32 mm. Also L. sakei 1I1 at 100 mg/ml exhibited significant (p < 0.05) α–glucosidase and tyrosinase inhibitory activities by 60.69 and 72.59 %, in terms of its anti-diabetic and anti-melanogenic potential, respectively. Moreover, L. sakei 1I1 displayed profound anti-cytopathic effect on MDCK cell line when treated with its ethanol extract (100 mg/ml), confirming its potent anti-viral efficacy against H1N1 influenza virus.ConclusionsThese findings reinforce the suggestions that L. sakei 1I1 isolated from the intestine of fresh water fish Z. koreanus might be a candidate of choice for using in pharmacological preparations as an effective drug.

Mycetoma: epidemiology, treatment challenges, and progress

Mycetoma is a chronic infectious disease of the subcutaneous tissue with a high morbidity. This disease is most commonly seen in countries between 30°N and 15°S of the equa- tor, but cases have also been seen in Europe and the USA. Due to the lack of proper prevalence data, currently the true burden of this disease is not known. Mycetoma can be caused by a large variety of microorganisms, both bacteria and fungi. Treatment of the disease depends on the etiology of the causative agent. Actinomycetoma is usually treated with antibiotics only and has a decent cure rate; eumycetoma is treated with a combination of antibiotics and surgery. Unfortunately, for eumycetoma, recurrent infections are common and amputations are still needed in a large proportion of the patients.

A Comprehensive Review of Aliphatic Hydrocarbon Biodegradation by Bacteria.

Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants. However, these compounds are slowly degraded by a large variety of microorganisms. Bacteria are able to degrade aliphatic saturated and unsaturated hydrocarbons via both aerobic and anaerobic pathways. Branched hydrocarbons and cyclic hydrocarbons are also degraded by bacteria. The aerobic bacteria use different types of oxygenases, including monooxygenase, cytochrome-dependent oxygenase and dioxygenase, to insert one or two atoms of oxygen into their targets. Anaerobic bacteria, on the other hand, employ a variety of simple organic and inorganic molecules, including sulphate, nitrate, carbonate and metals, for hydrocarbon oxidation.

Role of antimicrobial peptides in periodontal innate defense mechanism

The periodontal epithelium neighboring the tooth is precise to form a seal and attachment around the tooth. This exclusive function imparts unique challenges to the tissue and leads to certain vulnerabilities allied with periodontal disease, particularly in view of the continual exposure to the bacterial biofilm (dental plaque) that form that is formed on the tooth surface at the junction of the soft tissue. It is obvious that oral epithelial cells can counter unbroken microbial challenges from dental plaque by the production of antimicrobial peptides (AMPs), chemokines and cytokines that boost inflammation and immune response in periodontal tissues. AMPs are early responders of the innate immune system that search and destroy invading pathogens. The large variety of AMPs presumably allows for an effective response to the large variety of microorganisms that invade the mouth and airways. The present paper portrays the association between altered expression of AMPs and some types of periodontitis along with AMPs and their clinical significance in other oral diseases.

Immunolocalization and Correlation Frequencies of Lingual Antimicrobial Peptide and Lactoferrin in Bovine Alveolar Epithelium and Bovine Mammary Gland

Mastitis is most critical disease in dairy cows and causes huge cost in the dairy industry. To prevent and treat it, it is important to understand the mechanisms of immune function in the mammary gland. Innate immunity is non-specific acute-response immune function. Some components of innate immunity in the mammary gland are found, e.g. Lingual Antimicrobial Peptide (LAP), Lactoferrin (LF). These components are found to be localized in the alveolar epithelium of mammary gland. LAP belongs to the β-defensin family, and plays a crucial role in killing a large variety of microorganisms. LF belongs to an iron-binding glycoprotein and has antibacterial activity. It is reported that LF has been localized immunohistochemically in mammary epithelial cells of lactating cows. Our previous study revealed that secretion of LAP into milk proceeded to that of LF after lipopolysaccharide (LPS) injection into the mammary gland. From this result, it is hypothesized that immunohistochemistry probably shows positive to either LF or LAP but not both in the alveolus vs epithelium in the mammary gland. Therefore, the aim of the present study is to investigate the immunolocalization of LAP and LF in the same bovine mammary tissue. Bovine mammary tissues were collected in the slaughterhouse and were fixed with neutralized formalin immediately. Paraffin sections (2-um thickness) were processed with antigen retrieval treatment followed by blocking with casein milk. Sections were cultured with LF antibody or LAP antibody. Immunoreaction products were visualized by incubation with a DAB. LAP and LF were localized in the cytoplasm of epithelial cell of alveolus. In some cases, LAP and LF were seen clearly in the same alveoli of section. In other cases, some epithelial cells were stained only LAP, but not LF, and other epithelial cells of alveolus were stained only LF, but not LAP. These results suggest the possibility that LAP and LF are differentially synthesized in the alveolar epithelium and may support our previous findings that their secretion occurs at the different time course.

Accumulation of inorganic polyphosphate enables stress endurance and catalytic vigour in Pseudomonas putida KT2440

BackgroundAccumulation of inorganic polyphosphate (polyP), a persistent trait throughout the whole Tree of Life, is claimed to play a fundamental role in enduring environmental insults in a large variety of microorganisms. The share of polyP in the tolerance of the soil bacterium Pseudomonas putida KT2440 to a suite of physicochemical stresses has been studied on the background of its capacity as a host of oxidative biotransformations.ResultsCells lacking polyphosphate kinase (Ppk), which expectedly presented a low intracellular polyP level, were more sensitive to a number of harsh external conditions such as ultraviolet irradiation, addition of β-lactam antibiotics and heavy metals (Cd2+ and Cu2+). Other phenotypes related to a high-energy phosphate load (e.g., swimming) were substantially weakened as well. Furthermore, the ppk mutant was consistently less tolerant to solvents and its survival in stationary phase was significantly affected. In contrast, the major metabolic routes were not significantly influenced by the loss of Ppk as diagnosed from respiration patterns of the mutant in phenotypic microarrays. However, the catalytic vigour of the mutant decreased to about 50% of that in the wild-type strain as estimated from the specific growth rate of cells carrying the catabolic TOL plasmid pWW0 for m-xylene biodegradation. The catalytic phenotype of the mutant was restored by over-expressing ppk in trans. Some of these deficits could be explained by the effect of the ppk mutation on the expression profile of the rpoS gene, the stationary phase sigma factor, which was revealed by the analysis of a PrpoS → rpoS‘-’lacZ translational fusion. Still, every stress-related effect of lacking Ppk in P. putida was relatively moderate as compared to some of the conspicuous phenotypes reported for other bacteria.ConclusionsWhile polyP can be involved in a myriad of cellular functions, the polymer seems to play a relatively secondary role in the genetic and biochemical networks that ultimately enable P. putida to endure environmental stresses. Instead, the main value of polyP could be ensuring a reservoire of energy during prolonged starvation. This is perhaps one of the reasons for polyP persistence in live systems despite its apparent lack of essentiality.