scholarly journals Characterization of Spacesuit Associated Microbial Communities and Their Implications for NASA Missions

2021 ◽  
Vol 12 ◽  
Author(s):  
David Danko ◽  
Ganesh Babu Malli Mohan ◽  
Maria A. Sierra ◽  
Michelle Rucker ◽  
Nitin K. Singh ◽  
...  
Keyword(s):  
Microbial Population ◽  
Life Support ◽  
Wrist Joint ◽  
Bacterial Species ◽  
Planetary Science ◽  
Microbial Colonization ◽  
Planetary Protection ◽  
Microbial Distribution ◽  
Microbiological Methods ◽  
Cutibacterium Acnes

BackgroundCrewed National Aeronautics and Space Administration (NASA) missions to other solar system bodies are currently being planned. One high-profile scientific focus during such expeditions would be life detection, specifically the discovery of past or present microbial life, if they exist. However, both humans and associated objects typically carry a high microbial burden. Thus, it is essential to distinguish between microbes brought with the expedition and those present on the exploring planets. Modern spacesuits are unique, customized spacecraft which provide protection, mobility and life support to crew during spacewalks, yet they vent, and the mobility of microbes through spacesuits has not been studied.ResultsTo evaluate the microbial colonization of spacesuits, NASA used an Extravehicular Activity swab kit to examine viable microbial populations of 48 samples from spacesuits using both traditional microbiological methods and molecular sequencing methods. The cultivable microbial population ranged from below the detection limit to 9 × 102 colony forming units per 25 cm2 of sample and also significantly varied by the location. The cultivable microbial diversity was dominated by members of Bacillus, Arthrobacter, and Ascomycota. However, 16S rRNA-based viable bacterial burden ranged from 105 to 106 copies per 25 cm2 of sample. Shotgun metagenome sequencing revealed the presence of a diverse microbial population on the spacesuit surfaces, including Curtobacterium and Methylobacterium from across all sets of spacesuits in high abundance. Among bacterial species identified, higher abundance of Cutibacterium acnes, Methylobacterium oryzae, and M. phyllosphaerae reads were documented.ConclusionThe results of this study provide evidence that identical microbial strains may live on the wrist joint, inner gauntlet, and outer gauntlet of spacesuits. This raises the possibility, but does not confirm that microbial contaminants on the outside of the suits could contaminate planetary science operations unless additional measures are taken. Overall, these data provide the first estimate of microbial distribution associated with spacesuit surfaces, which will help future mission planners develop effective planetary protection strategies.

scholarly journals Characterization of Spacesuit Associated Microbial Communities and Their Implications for NASA Missions

2020 ◽  
Author(s):  
David Danko ◽  
Ganesh Babu Malli Mohan ◽  
Maria A Sierra ◽  
Michelle Rucker ◽  
Nitin Singh ◽  
...  
Keyword(s):  
Microbial Population ◽  
Life Support ◽  
Wrist Joint ◽  
Bacterial Species ◽  
Microbial Colonization ◽  
Planetary Protection ◽  
Microbiological Methods ◽  
Cutibacterium Acnes ◽  
Solar System Bodies ◽  
Metagenome Sequencing

Abstract Background. Crewed NASA missions to other solar system bodies are currently being planned. One high-profile scientific focus during such expeditions would be life detection, specifically the discovery of past or present microbial life, if they exist. However, both humans and associated objects typically carry a high microbial burden. Thus, it is essential to distinguish between microbes brought with the expedition and those present on the exploring planets. Modern spacesuits are unique, customized spacecraft which provide protection, mobility and life support to crew during spacewalks, yet they vent continuously, and the mobility of microbes through spacesuits has not been studied. Results. To evaluate the microbial colonization of spacesuits, NASA used an Extravehicular Activity swab kit to examine viable microbial populations of 48 samples from spacesuits using both traditional microbiological methods and molecular sequencing methods. The cultivable microbial population ranged from below the detection limit to 9 x 102 colony forming units per 25 cm2 of sample and also significantly varied by the location. The cultivable microbial diversity was dominated by members of Bacillus, Arthrobcter, and Ascomycota. However, 16S rRNA-based viable bacterial burden ranged from 105 to 106 copies per 25 cm2 of sample. Shotgun metagenome sequencing revealed the presence of a diverse microbial population on the spacesuit surfaces, including Curtobacterium and Methylobacterium from across all sets of spacesuits in high abundance. Among bacterial species identified, higher abundance of Cutibacterium acnes, Methylobacterium oryzae, and M. phyllosphaerae reads were documented. Conclusion. The results of this study provide evidence that identical microbial strains may live on the wrist joint, inner gauntlet, and outer gauntlet of spacesuits. This raises the possibility, but does not confirm, that viable microbes are able to migrate between the interior and exterior of spacesuits. Overall, these data provide the first estimate of microbial dispersion from internal to external spacesuit surfaces, which will help future mission planners develop effective planetary protection strategies.

Characterization of Serratia species and qualitative detection of Serratia marcescens in raw and pasteurized milk by an analytical method based on polymerase chain reaction

2021 ◽  
Vol 67 (2) ◽  
pp. 3453-3464
Author(s):  
Evelin Korcz ◽  
László Varga ◽  
Zoltán Kerényi
Keyword(s):  
Serratia Marcescens ◽  
Bacterial Species ◽  
Relevant Literature ◽  
Inhibitory Effect ◽  
Test Methods ◽  
In Vitro Assays ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Microbiological Methods

Serratia species are opportunistic pathogenic microorganisms primarily known as nosocomial infectious agents, which can also cause food quality problems. The appearance of the extracellular pigment-producing Serratia marcescens in cow’s milk causes its red discoloration, posing a challenge to the dairy industry and food certification laboratories. The detection of the bacterium by conventional procedures based on microbiological methods is time-consuming and labor-intensive, and in many cases does not lead to satisfactory results due to the competitive inhibitory effect of the accompanying microflora. Following the analysis of the relevant literature, the published endpoint PCR methods and the primers used for the detection of S. marcescens were evaluated in in silico and in vitro assays, and then the procedure was tested on farm milk samples. Using the method, a total of 60 raw and pasteurized milk samples were analyzed, more than half of which (i.e., 32) were identified as S. marcescens positive. The significance of our work is mainly represented by the application of the published test methods in food industry practice. Our results highlight to the importance of detecting this bacterial species.

scholarly journals Microcolony Cultivation on a Soil Substrate Membrane System Selects for Previously Uncultured Soil Bacteria

2005 ◽  
Vol 71 (12) ◽  
pp. 8714-8720 ◽  
Author(s):  
Belinda C. Ferrari ◽  
Svend J. Binnerup ◽  
Michael Gillings
Keyword(s):  
Soil Bacteria ◽  
Bacterial Species ◽  
Membrane System ◽  
Soil Extract ◽  
Growth Strategy ◽  
Soil Slurry ◽  
Polycarbonate Membrane ◽  
Microbiological Methods ◽  
Candidate Division ◽  
Excessive Nutrients

ABSTRACT Traditional microbiological methods of cultivation recover less than 1% of the total bacterial species, and the culturable portion of bacteria is not representative of the total phylogenetic diversity. Classical cultivation strategies are now known to supply excessive nutrients to a system and therefore select for fast-growing bacteria that are capable of colony or biofilm formation. New approaches to the cultivation of bacteria which rely on growth in dilute nutrient media or simulated environments are beginning to address this problem of selection. Here we describe a novel microcultivation method for soil bacteria that mimics natural conditions. Our soil slurry membrane system combines a polycarbonate membrane as a growth support and soil extract as the substrate. The result is abundant growth of uncharacterized bacteria as microcolonies. By combining microcultivation with fluorescent in situ hybridization, previously “unculturable” organisms belonging to cultivated and noncultivated divisions, including candidate division TM7, can be identified by fluorescence microscopy. Successful growth of soil bacteria as microcolonies confirmed that the missing culturable majority may have a growth strategy that is not observed when traditional cultivation indicators are used.

scholarly journals Trends in Antibiotic Resistance of Major Uropathogens

2020 ◽  
Author(s):  
Falah Hasan Obayes AL-Khikani
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Antimicrobial Susceptibility ◽  
Bacterial Species ◽  
High Rate ◽  
Control Group ◽  
Microbiological Methods ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

Around the world, there is no population clear from urinary tract infection (UTI), particularly among women. UTI is considered the most predominant bacterial infection. This study aimed to detect the incidence of the most common major uropathogens in patients severe from urinary tract infection with antibiotic sensitivity tests that assist urologist doctors for appropriate antimicrobial empirical therapy.Methods: This study was carried in a private laboratory in Babil city, Iraq from May 2019 to May 2020. Totally 70 individuals suffering from clear symptoms of UTI, as well as, 20 healthy persons participated in this study as a control group. Then, the standard microbiological methods carried out to isolate and identify bacterial species. Antimicrobial susceptibility tests were performed using different antimicrobial discs by applying the Kirby–Bauer disc diffusion method.Results: Totally, 90 specimens were obtained from them 20 control group, 19 with no growth, and 51 patients with bacterial growth distributed as 43 (83%) females and 8 (17%) males. E. coli were the most common predominant organisms. All isolates were showed a high rate of resistance to evaluated cephalosporins 100% and 82% to cefotaxime and ceftriaxone respectively, while very low resistance recorded in Aminoglycosides 20% and 13% to Gentamicin and amikacin respectively. Most age group infected with UTI was 21-40 years old.Conclusion: The current study showed an increasing burden of urinary tract infection caused by various bacteria implicated in UTI that causes changeable sensitivity to various antimicrobial agents. Therefore, in clinical use appropriate medications should be selected based on the data obtained from antimicrobial susceptibility tests.

scholarly journals Colonization of central venous catheter in the intensive care units at the Institute of Cardiovascular Disease "Dedinje": One year study

2005 ◽  
Vol 52 (3) ◽  
pp. 33-37
Author(s):  
Ivana Cirkovic ◽  
Vera Mijac ◽  
Milena Svabic-Vlahovic ◽  
S. Dukic ◽  
I. Ilic ◽  
...  
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Antimicrobial Agents ◽  
Microbial Colonization ◽  
Central Venous ◽  
Candida Spp ◽  
Icu Patients ◽  
Gram Negative ◽  
Microbiological Methods ◽  
Increased Risk

Objectives: The application of Central Venous Catheters (CVC) is associated with increased risk of microbial colonization and infection. The aim of present study was to assess the frequency of pathogens colonizing CVC and to determine their susceptibility pattern to various antimicrobial agents. Materials and methods: A total of 253 samples of CVC from intensive care units (ICU) patients were received for culture during 2003. All microorganisms were identified by standard microbiological methods and the susceptibility to antimicrobial agents was determined according to NCCLS recommendations. Results: A total of 184 (72.7%) cultures were positive and 223 pathogens were isolated. Coagulase negative staphylococci (CNS) were the dominant isolates (24.7%), followed by Enterobacter spp. (12.1%), Pseudomonas spp. (11.7%), Enterococcus spp. (9.9%), Klebsiella spp. (8.6%), Candida spp. (7.6%), Acinetobacter spp. (7.6%), other Gram negative nonfermentative bacilli (5.8%), Serratia spp. (4.5%), Staphylococcus aureus (2.6%), Proteus mirabilis (2.2%), E. coli (1.8%) and Citrobacter spp. (0.9%). Meropenem (84.5%) and vancomycin (100%) remain the most effective antimicrobial agents against Gram negative and Gram positive bacteria, respectively. Conclusion: Gram negative bacilli and CNS are the commonest microorganisms colonizing CVC from ICU patients. The increasing resistance of the bacteria to antimicrobial agents is the major problem in spite of restricted policy of using antimicrobial agents in ICU.

Characterizing the Microbiome of the Contracted Breast Capsule Using Next Generation Sequencing

2020 ◽  
Author(s):  
Jonathan Cook ◽  
Casey J Holmes ◽  
Roger Wixtrom ◽  
Martin I Newman ◽  
Jason N Pozner
Keyword(s):  
Next Generation Sequencing ◽  
Capsular Contracture ◽  
Bacterial Species ◽  
Fungal Species ◽  
Augmentation Mammoplasty ◽  
Next Generation ◽  
Level Of Evidence ◽  
Cutibacterium Acnes ◽  
Microbial Dna ◽  
Generation Sequencing

Abstract Background Recent work suggests that bacterial biofilms play a role in capsular contracture (CC). However, traditional culture techniques provide only a limited understanding of the bacterial communities present within the contracted breast. Next generation sequencing (NGS) represents an evolution of polymerase chain reaction technology that can sequence all DNA present in a given sample. Objectives The aim of this study was to utilize NGS to characterize the bacterial microbiome of the capsule in patients with CC following cosmetic breast augmentation. Methods We evaluated 32 consecutive patients with Baker grade III or IV CC following augmentation mammoplasty. Specimens were obtained from all contracted breasts (n = 53) during capsulectomy. Tissue specimens from contracted capsules as well as intraoperative swabs of the breast capsule and implant surfaces were obtained. Samples were sent to MicroGenDX Laboratories (Lubbock, TX) for NGS. Results Specimens collected from 18 of 32 patients (56%) revealed the presence of microbial DNA. The total number of positive samples was 22 of 53 (42%). Sequencing identified a total of 120 unique bacterial species and 6 unique fungal species. Specimens with microbial DNA yielded a mean [standard deviation] of 8.27 [4.8] microbial species per patient. The most frequently isolated species were Escherichia coli (25% of all isolates), Diaphorobacter nitroreducens (12%), Cutibacterium acnes (12%), Staphylococcus epidermidis (11%), fungal species (7%), and Staphylococcus aureus (6%). Conclusions NGS enables characterization of the bacterial ecosystem surrounding breast implants in unprecedented detail. This is a critical step towards understanding the role this microbiome plays in the development of CC. Level of Evidence: 4

scholarly journals Assessment of a Multiplex Serological Test for the Diagnosis of Prosthetic Joint Infection: a Prospective Multicentre Study

2020 ◽  
Vol 5 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Pascale Bémer ◽  
Céline Bourigault ◽  
Anne Jolivet-Gougeon ◽  
Chloé Plouzeau-Jayle ◽  
Carole Lemarie ◽  
...  
Keyword(s):  
Negative Predictive Value ◽  
Predictive Value ◽  
Serological Test ◽  
Bacterial Species ◽  
Joint Infection ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Prosthetic Joint ◽  
Prosthetic Joint Infections ◽  
Cutibacterium Acnes

Abstract. Introduction: The diagnosis of prosthetic joint infections (PJIs) can be difficult in the chronic stage and is based on clinical and paraclinical evidence. A minimally invasive serological test against the main pathogens encountered during PJI would distinguish PJI from mechanical loosening.Methods: We performed a prospective, multicentre, cross-sectional study to assess the contribution of serology in the diagnosis of PJI. Over a 2-year period, all patients undergoing prosthesis revision were included in the study. A C-reactive protein assay and a serological test specifically designed against 5 bacterial species (Staphylococcus aureus, S. epidermidis, S. lugdunensis, Streptococcus agalactiae, Cutibacterium acnes) were performed preoperatively. Five samples per patient were taken intraoperatively during surgery. The diagnosis of PJI was based on clinical and bacteriological criteria according to guidelines.Results: Between November 2015 and November 2017, 115 patients were included, 49 for a chronic PJI and 66 for a mechanical problem. Among patients with PJI, a sinus tract was observed in 32.6% and a C-reactive protein level ≥10 mg/L in 74.5%. The PJI was monomicrobial in 43 cases (targeted staphylococci, 24; S. agalactiae, 1; C. acnes, 2; others, 16), and polymicrobial in 6 cases (12.2%). Sensitivity, specificity, positive predictive value and negative predictive value were 75.0%, 82.1%, 58.3% and 90.8%, respectively, for targeted staphylococci. Specificity/negative predictive value was 97.3%/100% for S. agalactiae and 83.8% /96.9% for C. acnes.Conclusions: The serological tests are insufficient to affirm the diagnosis of PJI for the targeted bacteria. Nevertheless, the excellent NPV may help clinicians to exclude PJI.

scholarly journals Supplementation of live yeast based feed additive in early life promotes rumen microbial colonization and fibrolytic potential in lambs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Frédérique Chaucheyras-Durand ◽  
Aurélie Ameilbonne ◽  
Pauline Auffret ◽  
Mickaël Bernard ◽  
Marie-Madeleine Mialon ◽  
...  
Keyword(s):  
Positive Impact ◽  
Bacterial Species ◽  
Animal Health ◽  
Microbial Colonization ◽  
Feed Additive ◽  
Gut Development ◽  
Host Animal ◽  
Microbial Composition ◽  
Rumen Microbiota ◽  
Live Yeast

AbstractRumen microbiota is of paramount importance for ruminant digestion efficiency as the microbial fermentations supply the host animal with essential sources of energy and nitrogen. Early separation of newborns from the dam and distribution of artificial milk (Artificial Milking System or AMS) could impair rumen microbial colonization, which would not only affect rumen function but also have possible negative effects on hindgut homeostasis, and impact animal health and performance. In this study, we monitored microbial communities in the rumen and the feces of 16 lambs separated from their dams from 12 h of age and artificially fed with milk replacer and starter feed from d8, in absence or presence of a combination of the live yeast Saccharomyces cerevisiae CNCM I-1077 and selected yeast metabolites. Microbial groups and targeted bacterial species were quantified by qPCR and microbial diversity and composition were assessed by 16S rDNA amplicon sequencing in samples collected from birth to 2 months of age. The fibrolytic potential of the rumen microbiota was analyzed with a DNA microarray targeting genes coding for 8 glycoside hydrolase (GH) families. In Control lambs, poor establishment of fibrolytic communities was observed. Microbial composition shifted as the lambs aged. The live yeast supplement induced significant changes in relative abundances of a few bacterial OTUs across time in the rumen samples, among which some involved in crucial rumen function, and favored establishment of Trichostomatia and Neocallimastigaceae eukaryotic families. The supplemented lambs also harbored greater abundances in Fibrobacter succinogenes after weaning. Microarray data indicated that key cellulase and hemicellulase encoding-genes were present from early age in the rumen and that in the Supplemented lambs, a greater proportion of hemicellulase genes was present. Moreover, a higher proportion of GH genes from ciliate protozoa and fungi was found in the rumen of those animals. This yeast combination improved microbial colonization in the maturing rumen, with a potentially more specialized ecosystem towards efficient fiber degradation, which suggests a possible positive impact on lamb gut development and digestive efficiency.

scholarly journals Growth of bifidobacteria in mammalian milk

2013 ◽  
Vol 58 (No. 3) ◽  
pp. 99-105 ◽  
Author(s):  
Š. Ročková ◽  
V. Rada ◽  
J. Havlík ◽  
R. Švejstil ◽  
E. Vlková ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Human Milk ◽  
Bacterial Species ◽  
Intestinal Bacteria ◽  
Bifidobacterium Bifidum ◽  
Microbial Colonization ◽  
Animal Origin ◽  
Good Growth ◽  
Animal Milk ◽  
Species Specific

Microbial colonization of the mammalian intestine begins at birth, when from a sterile state a newborn infant is exposed to an external environment rich in various bacterial species. An important group of intestinal bacteria comprises bifidobacteria. Bifidobacteria represent major intestinal microbiota during the breast-feeding period. Animal milk contains all crucial nutrients for babies’ intestinal microflora. The aim of our work was to test the influence of different mammalian milk on the growth of bifidobacteria. The growth of seven strains of bifidobacteria in human milk, the colostrum of swine, cow’s milk, sheep’s milk, and rabbit’s milk was tested. Good growth accompanied by the production of lactic acid was observed not only in human milk, but also in the other kinds of milk in all three strains of Bifidobacterium bifidum of different origin. Human milk selectively supported the production of lactic acid of human bifidobacterial isolates, especially the Bifidobacterium bifidum species. The promotion of bifidobacteria by milk is species-specific. Human milk contains a key factor for the growth of specific species or strains of human-origin bifidobacteria compared to other kinds of milk. In contrast, some components (maybe lysozyme) of human milk inhibited the growth of Bifidobacterium animalis. Animal-origin strains of bifidobacteria were not able to significantly grow even in milk of animal origin, with the exception of B. animalis subsp. lactis 1,2, which slightly grew in sheep’s milk.

Sign in / Sign up

Export Citation Format

Share Document