scholarly journals Strains of the Harmful Cyanobacterium Microcystis aeruginosa Differ in Gene Expression and Activity of Inorganic Carbon Uptake Systems at Elevated CO2Levels

2015 ◽  
Vol 81 (22) ◽  
pp. 7730-7739 ◽  
Author(s):  
Giovanni Sandrini ◽  
Dennis Jakupovic ◽  
Hans C. P. Matthijs ◽  
Jef Huisman
Keyword(s):  
Gene Expression ◽  
Inorganic Carbon ◽  
Constitutive Expression ◽  
Cyanobacterial Blooms ◽  
Uptake System ◽  
Carbonic Anhydrases ◽  
Content Type ◽  
High Affinity ◽  
Activity Measurements ◽  
Bicarbonate Uptake

ABSTRACTCyanobacteria are generally assumed to be effective competitors at low CO2levels because of their efficient CO2-concentrating mechanism (CCM), and yet how bloom-forming cyanobacteria respond to rising CO2concentrations is less clear. Here, we investigate changes in CCM gene expression at ambient CO2(400 ppm) and elevated CO2(1,100 ppm) in six strains of the harmful cyanobacteriumMicrocystis. All strains downregulatedcmpAencoding the high-affinity bicarbonate uptake system BCT1, whereas both the low- and high-affinity CO2uptake genes were expressed constitutively. Four strains downregulated the bicarbonate uptake genesbicAand/orsbtA, whereas two strains showed constitutive expression of thebicA-sbtAoperon. In one of the latter strains, a transposon insert inbicAcaused lowbicAandsbtAtranscript levels, which made this strain solely dependent on BCT1 for bicarbonate uptake. Activity measurements of the inorganic carbon (Ci) uptake systems confirmed the CCM gene expression results. Interestingly, genes encoding the RuBisCO enzyme, structural carboxysome components, and carbonic anhydrases were not regulated. Hence,Microcystismainly regulates the initial uptake of inorganic carbon, which might be an effective strategy for a species experiencing strongly fluctuating Ciconcentrations. Our results show that CCM gene regulation ofMicrocystisvaries among strains. The observed genetic and phenotypic variation in CCM responses may offer an important template for natural selection, leading to major changes in the genetic composition of harmful cyanobacterial blooms at elevated CO2.

scholarly journals Spot 42 Small RNA Regulates Arabinose-Inducible araBAD Promoter Activity by Repressing Synthesis of the High-Affinity Low-Capacity Arabinose Transporter

2016 ◽  
Vol 199 (3) ◽  
Author(s):  
Jiandong Chen ◽  
Susan Gottesman
Keyword(s):  
Gene Expression ◽  
Promoter Activity ◽  
Transcriptional Control ◽  
Bacterial Species ◽  
High Capacity ◽  
Constitutive Expression ◽  
Receptor Protein ◽  
Control Of Gene Expression ◽  
Content Type ◽  
High Affinity

ABSTRACT The l-arabinose-inducible araBAD promoter (PBAD) enables tightly controlled and tunable expression of genes of interest in a broad range of bacterial species. It has been used successfully to study bacterial sRNA regulation, where PBAD drives expression of target mRNA translational fusions. Here we report that in Escherichia coli, Spot 42 sRNA regulates PBAD promoter activity by affecting arabinose uptake. We demonstrate that Spot 42 sRNA represses araF, a gene encoding the AraF subunit of the high-affinity low-capacity arabinose transporter AraFGH, through direct base-pairing interactions. We further show that endogenous Spot 42 sRNA is sufficient to repress araF expression under various growth conditions. Finally, we demonstrate this posttranscriptional repression has a biological consequence, decreasing the induction of PBAD at low levels of arabinose. This problem can be circumvented using strategies reported previously for avoiding all-or-none induction behavior, such as through constitutive expression of the low-affinity high-capacity arabinose transporter AraE or induction with a higher concentration of inducers. This work adds araF to the set of Spot 42-regulated genes, in agreement with previous studies suggesting that Spot 42, itself negatively regulated by the cyclic AMP (cAMP) receptor protein-cAMP complex, reinforces the catabolite repression network. IMPORTANCE The bacterial arabinose-inducible system is widely used for titratable control of gene expression. We demonstrate here that a posttranscriptional mechanism mediated by Spot 42 sRNA contributes to the functionality of the PBAD system at subsaturating inducer concentrations by affecting inducer uptake. Our finding extends the inputs into the known transcriptional control for the PBAD system and has implications for improving its usage for tunable gene expression.

scholarly journals Antibacterial Mechanism of 405-Nanometer Light-Emitting Diode against Salmonella at Refrigeration Temperature

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Min-Jeong Kim ◽  
Hyun-Gyun Yuk
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Light Emitting Diode ◽  
Dna Oxidation ◽  
Uptake System ◽  
Antibacterial Mechanism ◽  
Content Type ◽  
Light Emitting ◽  
Expression Levels ◽  
Gene Expression Levels

ABSTRACT The aim of this study was to elucidate the antibacterial mechanism of 405 ± 5-nm light-emitting diode (LED) illumination against Salmonella at 4°C in phosphate-buffered saline (PBS) by determining endogenous coproporphyrin content, DNA oxidation, damage to membrane function, and morphological change. Gene expression levels, including of oxyR, recA, rpoS, sodA, and soxR, were also examined to understand the response of Salmonella to LED illumination. The results showed that Salmonella strains responded differently to LED illumination, revealing that S. enterica serovar Enteritidis (ATCC 13076) and S. enterica subsp. enterica serovar Saintpaul (ATCC 9712) were more susceptible and resistant, respectively, than the 16 other strains tested. There was no difference in the amounts of endogenous coproporphyrin in the two strains. Compared with that in nonilluminated cells, the DNA oxidation levels in illuminated cells increased. In illuminated cells, we observed a loss of efflux pump activity, damage to the glucose uptake system, and changes in membrane potential and integrity. Transmission electron microscopy revealed a disorganization of chromosomes and ribosomes due to LED illumination. The levels of the five genes measured in the nonilluminated and illuminated S. Saintpaul cells were upregulated in PBS at a set temperature of 4°C, indicating that increased gene expression levels might be due to a temperature shift and nutrient deficiency rather than to LED illumination. In contrast, only oxyR in S. Enteritidis cells was upregulated. Thus, different sensitivities of the two strains to LED illumination were attributed to differences in gene regulation. IMPORTANCE Bacterial inactivation using visible light has recently received attention as a safe and environmentally friendly technology, in contrast with UV light, which has detrimental effects on human health and the environment. This study was designed to understand how 405 ± 5-nm light-emitting diode (LED) illumination kills Salmonella strains at refrigeration temperature. The data clearly demonstrated that the effectiveness of LED illumination on Salmonella strains depended highly on the serotype and strain. Our findings also revealed that its antibacterial mechanism was mainly attributed to DNA oxidation and a loss of membrane functions rather than membrane lipid peroxidation, which has been proposed by other researchers who studied the antibacterial effect of LED illumination by adding exogenous photosensitizers, such as chlorophyllin and hypericin. Therefore, this study suggests that the detailed antibacterial mechanisms of 405-nm LED illumination without additional photosensitizers may differ from that by exogenous photosensitizers. Furthermore, a change in stress-related gene regulation may alter the susceptibility of Salmonella cells to LED illumination at refrigeration temperature. Thus, our study provides new insights into the antibacterial mechanism of 405 ± 5-nm LED illumination on Salmonella cells.

scholarly journals Two Ways To Convert a Low-Affinity Potassium Channel to High Affinity: Control of Bacillus subtilis KtrCD by Glutamate

2020 ◽  
Vol 202 (12) ◽  
Author(s):  
Larissa Krüger ◽  
Christina Herzberg ◽  
Robert Warneke ◽  
Anja Poehlein ◽  
Janina Stautz ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Potassium Channel ◽  
Living Cell ◽  
Potassium Uptake ◽  
Selectivity Filter ◽  
Uptake System ◽  
Content Type ◽  
Apparent Affinity ◽  
High Affinity ◽  
External Potassium

ABSTRACT Potassium and glutamate are the major cation and anion, respectively, in every living cell. Due to the high concentrations of both ions, the cytoplasm of all cells can be regarded as a potassium glutamate solution. This implies that the concentrations of both ions need to be balanced. While the control of potassium uptake by glutamate is well established for eukaryotic cells, much less is known about the mechanisms that link potassium homeostasis to glutamate availability in bacteria. Here, we have discovered that the availability of glutamate strongly decreases the minimal external potassium concentration required for the highly abundant Bacillus subtilis potassium channel KtrCD to accumulate potassium. In contrast, the inducible KtrAB and KimA potassium uptake systems have high apparent affinities for potassium even in the absence of glutamate. Experiments with mutant strains revealed that the KtrD subunit responds to the presence of glutamate. For full activity, KtrD synergistically requires the presence of the regulatory subunit KtrC and of glutamate. The analysis of suppressor mutants of a strain that has KtrCD as the only potassium uptake system and that experiences severe potassium starvation identified a mutation in the ion selectivity filter of KtrD (Gly282 to Val) that similarly results in a strongly glutamate-independent increase of the apparent affinity for potassium. Thus, this work has identified two conditions that increase the apparent affinity of KtrCD for potassium, i.e., external glutamate and the acquisition of a single point mutation in KtrD. IMPORTANCE In each living cell, potassium is required for maintaining the intracellular pH and for the activity of essential enzymes. Like most other bacteria, Bacillus subtilis possesses multiple low- and high-affinity potassium uptake systems. Their activity is regulated by the second messenger cyclic di-AMP. Moreover, the pools of the most abundant ions potassium and glutamate must be balanced. We report two conditions under which the low-affinity potassium channel KtrCD is able to mediate potassium uptake at low external potassium concentrations: physiologically, the presence of glutamate results in a severely increased potassium uptake. Moreover, this is achieved by a mutation affecting the selectivity filter of the KtrD channel. These results highlight the integration between potassium and glutamate homeostasis in bacteria.

scholarly journals A Capsular Polysaccharide-Specific Antibody Alters Streptococcus pneumoniae Gene Expression during Nasopharyngeal Colonization of Mice

2018 ◽  
Vol 86 (7) ◽  
Author(s):  
Christopher R. Doyle ◽  
Jee-Young Moon ◽  
Johanna P. Daily ◽  
Tao Wang ◽  
Liise-anne Pirofski
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Streptococcus Pneumoniae ◽  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Lavage Fluid ◽  
Uptake System ◽  
Content Type

ABSTRACT Pneumococcal conjugate vaccines (PCV) elicit opsonophagocytic (opsonic) antibodies to pneumococcal capsular polysaccharides (PPS) and reduce nasopharyngeal (NP) colonization by vaccine-included Streptococcus pneumoniae serotypes. However, nonopsonic antibodies may also be important for protection against pneumococcal disease. For example, 1E2, a mouse IgG1 monoclonal antibody (MAb) to the serotype 3 (ST3) PPS (PPS3), reduced ST3 NP colonization in mice and altered ST3 gene expression in vitro . Here, we determined whether 1E2 affects ST3 gene expression in vivo during colonization of mice by performing RNA sequencing on NP lavage fluid from ST3-infected mice treated with 1E2, a control MAb, or phosphate-buffered saline. Compared to the results for the controls, 1E2 significantly altered the expression of over 50 genes. It increased the expression of the piuBCDA operon, which encodes an iron uptake system, and decreased the expression of dpr , which encodes a protein critical for resistance to oxidative stress. 1E2-mediated effects on ST3 in vivo required divalent binding, as Fab fragments did not reduce NP colonization or alter ST3 gene expression. In vitro , 1E2 induced dose-dependent ST3 growth arrest and altered piuB and dpr expression, whereas an opsonic PPS3 MAb, 5F6, did not. 1E2-treated bacteria were more sensitive to hydrogen peroxide and the iron-requiring antibiotic streptonigrin, suggesting that 1E2 may increase iron import and enhance sensitivity to oxidative stress. Finally, 1E2 also induced rapid capsule shedding in vitro , suggesting that this may initiate 1E2-induced changes in sensitivity to oxidative stress and gene expression. Our data reveal a novel mechanism of direct, antibody-mediated antibacterial activity that could inform new directions in antipneumococcal therapy and vaccine development.

scholarly journals Agrobacterium tumefaciens Zur Regulates the High-Affinity Zinc Uptake System TroCBA and the Putative Metal Chaperone YciC, along with ZinT and ZnuABC, for Survival under Zinc-Limiting Conditions

2016 ◽  
Vol 82 (12) ◽  
pp. 3503-3514 ◽  
Author(s):  
Paweena Chaoprasid ◽  
Thanittra Dokpikul ◽  
Jaruwan Johnrod ◽  
Sirin Sirirakphaisarn ◽  
Sumontha Nookabkaew ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Metal Binding ◽  
Zinc Uptake ◽  
Growth Defect ◽  
Pcr Analysis ◽  
Uptake System ◽  
Bacterial Survival ◽  
Content Type ◽  
High Affinity ◽  
Wide Range

ABSTRACTAgrobacterium tumefacienshas a cluster of genes (Atu3178, Atu3179, and Atu3180) encoding an ABC-type transporter, here namedtroA,troB, andtroC, respectively, which is shown here to be a zinc-specific uptake system. Reverse transcription (RT)-PCR analysis confirmed thattroA,troB, andtroCare cotranscribed, withtroCas the first gene of the operon. TheyciC(Atu3181) gene is transcribed in the opposite orientation to that of thetroCBAoperon and belongs to a metal-binding GTPase family. Expression oftroCBAandyciCwas inducible under zinc-limiting conditions and was controlled by the zinc uptake regulator, Zur. Compared to the wild type, the mutant strain lackingtroCwas hypersensitive to a metal chelator, EDTA, and the phenotype could be rescued by the addition of zinc, while the strain with a singleyciCmutation showed no phenotype. However,yciCwas important for survival under zinc limitation when eithertroCorzinTwas inactivated. The periplasmic zinc-binding protein, ZinT, could not function when TroC was inactivated, suggesting that ZinT may interact with TroCBA in zinc uptake. Unlike many other bacteria, the ABC-type transporter ZnuABC was not the major zinc uptake system inA. tumefaciens. However, the important role ofA. tumefaciensZnuABC was revealed when TroCBA was impaired. The strain containing double mutations in theznuAandtroCgenes exhibited a growth defect in minimal medium.A. tumefaciensrequires cooperation of zinc uptake systems and zinc chaperones, including TroCBA, ZnuABC, ZinT, and YciC, for survival under a wide range of zinc-limiting conditions.IMPORTANCEBoth host and pathogen battle over access to essential metals, including zinc. In low-zinc environments, physiological responses that make it possible to acquire enough zinc are important for bacterial survival and could determine the outcome of host-pathogen interactions.A. tumefacienswas found to operate a novel pathway for zinc uptake in which ZinT functions in concert with the high-affinity zinc importer TroCBA.

scholarly journals Role of Ferric Reductases in Iron Acquisition and Virulence in the Fungal Pathogen Cryptococcus neoformans

2013 ◽  
Vol 82 (2) ◽  
pp. 839-850 ◽  
Author(s):  
Sanjay Saikia ◽  
Debora Oliveira ◽  
Guanggan Hu ◽  
James Kronstad
Keyword(s):  
Cryptococcus Neoformans ◽  
Iron Acquisition ◽  
Antifungal Drugs ◽  
Growth Defect ◽  
Uptake System ◽  
Ferric Reductase ◽  
Pathogenic Yeast ◽  
Content Type ◽  
High Affinity ◽  
Cryptococcal Disease

ABSTRACTIron acquisition is critical for the ability of the pathogenic yeastCryptococcus neoformansto cause disease in vertebrate hosts. In particular, iron overload exacerbates cryptococcal disease in an animal model, defects in iron acquisition attenuate virulence, and iron availability influences the expression of major virulence factors.C. neoformansacquires iron by multiple mechanisms, including a ferroxidase-permease high-affinity system, siderophore uptake, and utilization of both heme and transferrin. In this study, we examined the expression of eight candidate ferric reductase genes and their contributions to iron acquisition as well as to ferric and cupric reductase activities. We found that loss of theFRE4gene resulted in a defect in production of the virulence factor melanin and increased susceptibility to azole antifungal drugs. In addition, theFRE2gene was important for growth on the iron sources heme and transferrin, which are relevant for proliferation in the host. Fre2 may participate with the ferroxidase Cfo1 of the high-affinity uptake system for growth on heme, because a mutant lacking both genes showed a more pronounced growth defect than thefre2single mutant. A role for Fre2 in iron acquisition is consistent with the attenuation of virulence observed for thefre2mutant. This mutant also was defective in accumulation in the brains of infected mice, a phenotype previously observed for mutants with defects in high-affinity iron uptake (e.g., thecfo1mutant). Overall, this study provides a more detailed view of the iron acquisition components required forC. neoformansto cause cryptococcosis.

scholarly journals A Carbonic Anhydrase Pseudogene Sensitizes Select Brucella Lineages to Low CO2 Tension

2019 ◽  
Vol 201 (22) ◽  
Author(s):  
Lydia M. Varesio ◽  
Jonathan W. Willett ◽  
Aretha Fiebig ◽  
Sean Crosson
Keyword(s):  
Gene Expression ◽  
Carbonic Anhydrase ◽  
Transcriptional Activation ◽  
Carbonic Anhydrases ◽  
Loss Of Function ◽  
Content Type ◽  
Reading Frame ◽  
Animal Host ◽  
Standard Atmosphere ◽  
Carbonic Anhydrase Gene

ABSTRACT Brucella spp. are intracellular pathogens that cause a disease known as brucellosis. Though the genus is highly monomorphic at the genetic level, species have animal host preferences and some defining physiologic characteristics. Of note is the requirement for CO2 supplementation to cultivate particular species, which confounded early efforts to isolate B. abortus from diseased cattle. Differences in the capacity of Brucella species to assimilate CO2 are determined by mutations in the carbonic anhydrase gene, bcaA. Ancestral single-nucleotide insertions in bcaA have resulted in frameshifted pseudogenes in B. abortus and B. ovis lineages, which underlie their inability to grow under the low CO2 tension of a standard atmosphere. Incubation of wild-type B. ovis in air selects for mutations that “rescue” a functional bcaA reading frame, which enables growth under low CO2 and enhances the growth rate under high CO2. Accordingly, we show that heterologous expression of functional Escherichia coli carbonic anhydrases enables B. ovis growth in air. Growth of B. ovis is acutely sensitive to a reduction in CO2 tension, while frame-rescued B. ovis mutants are insensitive to CO2 shifts. B. ovis initiates a gene expression program upon CO2 downshift that resembles the stringent response and results in transcriptional activation of its type IV secretion system. Our study provides evidence that loss-of-function insertion mutations in bcaA sensitize the response of B. ovis and B. abortus to reduced CO2 tension relative to that of other Brucella lineages. CO2-dependent starvation and virulence gene expression programs in these species may influence persistence or transmission in natural hosts. IMPORTANCE Brucella spp. are highly related, but they exhibit differences in animal host preference that must be determined by genome sequence differences. B. ovis and the majority of B. abortus strains require high CO2 tension to be cultivated in vitro and harbor conserved insertional mutations in the carbonic anhydrase gene, bcaA, which underlie this trait. Mutants that grow in a standard atmosphere, first reported nearly a century ago, are easily selected in the laboratory. These mutants harbor varied indel polymorphisms in bcaA that restore its consensus reading frame and rescue its function. Loss of bcaA function has evolved independently in the B. ovis and B. abortus lineages and results in a dramatically increased sensitivity to CO2 limitation.

scholarly journals Role of Spermidine in Overwintering of Cyanobacteria

2015 ◽  
Vol 197 (14) ◽  
pp. 2325-2334 ◽  
Author(s):  
Xiangzhi Zhu ◽  
Qiong Li ◽  
Chuntao Yin ◽  
Xiantao Fang ◽  
Xudong Xu
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Light Stress ◽  
Protein Carbonylation ◽  
Cyanobacterial Blooms ◽  
Α Subunit ◽  
Content Type ◽  
Pcc 6803

ABSTRACTPolyamines are found in all groups of cyanobacteria, but their role in environmental adaptation has been barely investigated. InSynechocystissp. strain PCC 6803, inactivation of spermidine synthesis genes significantly reduced the survivability under chill (5°C)-light stress, and the survivability could be restored by addition of spermidine. To analyze the effects of spermidine on gene expression at 5°C,lacZwas expressed from the promoter of carboxy(nor)spermidine decarboxylase gene (CASDC) inSynechocystis.Synechocystis6803::PCASDC-lacZpretreated at 15°C showed a high level of LacZ activity for a long period of time at 5°C; without the pretreatment or with protein synthesis inhibited at 5°C, the enzyme activity gradually decreased. In a spermidine-minus mutant harboring PCASDC-lacZ,lacZshowed an expression pattern as if protein synthesis were inhibited at 5°C, even though the stability of its mRNA increased. Four other genes, includingrpoAthat encodes the α subunit of RNA polymerase, showed similar expression patterns. The chill-light stress led to a rapid increase of protein carbonylation inSynechocystis. The protein carbonylation then quickly returned to the background level in the wild type but continued to slowly increase in the spermidine-minus mutant. Our results indicate that spermidine promotes gene expression and replacement of damaged proteins in cyanobacteria under the chill-light stress in winter.IMPORTANCEOutbreak of cyanobacterial blooms in freshwater lakes is a worldwide environmental problem. In the annual cycle of bloom-forming cyanobacteria, overwintering is the least understood stage. Survival ofSynechocystissp. strain PCC 6803 under long-term chill (5°C)-light stress has been established as a model for molecular studies on overwintering of cyanobacteria. Here, we show that spermidine, the most common polyamine in cyanobacteria, promotes the survivability ofSynechocystisunder long-term chill-light stress and that the physiological function is based on its effects on gene expression and recovery from protein damage. This is the first report on the role of polyamines in survival of overwintering cyanobacteria. We also analyzed spermidine synthesis pathways in cyanobacteria on the basis of bioinformatic and experimental data.

scholarly journals A Modular, Tn7-Based System for Making Bioluminescent or Fluorescent Salmonella and Escherichia coli Strains

2016 ◽  
Vol 82 (16) ◽  
pp. 4931-4943 ◽  
Author(s):  
Dylan J. Shivak ◽  
Keith D. MacKenzie ◽  
Nikole L. Watson ◽  
J. Alex Pasternak ◽  
Brian D. Jones ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
High Throughput ◽  
Constitutive Expression ◽  
Bacterial Strains ◽  
Efficient System ◽  
Transposase Gene ◽  
Content Type ◽  
E Coli

ABSTRACTOur goal was to develop a robust tagging method that can be used to track bacterial strainsin vivo. To address this challenge, we adapted two existing systems: a modular plasmid-based reporter system (pCS26) that has been used for high-throughput gene expression studies inSalmonellaandEscherichia coliand Tn7transposition. We generated kanamycin- and chloramphenicol-resistant versions of pCS26 with bacterial luciferase, green fluorescent protein (GFP), and mCherry reporters under the control of σ70-dependent promoters to provide three different levels of constitutive expression. We improved upon the existing Tn7system by modifying the delivery vector to accept pCS26 constructs and moving the transposase genes from a nonreplicating helper plasmid into a temperature-sensitive plasmid that can be conditionally maintained. This resulted in a 10- to 30-fold boost in transposase gene expression and transposition efficiencies of 10−8to 10−10inSalmonella entericaserovar Typhimurium andE. coliAPEC O1, whereas the existing Tn7system yielded no successful transposition events. The new reporter strains displayed reproducible signaling in microwell plate assays, confocal microscopy, andin vivoanimal infections. We have combined two flexible and complementary tools that can be used for a multitude of molecular biology applications within theEnterobacteriaceae. This system can accommodate new promoter-reporter combinations as they become available and can help to bridge the gap between modern, high-throughput technologies and classical molecular genetics.IMPORTANCEThis article describes a flexible and efficient system for tagging bacterial strains. Using our modular plasmid system, a researcher can easily change the reporter type or the promoter driving expression and test the parameters of these new constructsin vitro. Selected constructs can then be stably integrated into the chromosomes of desired strains in two simple steps. We demonstrate the use of this system inSalmonellaandE. coli, and we predict that it will be widely applicable to other bacterial strains within theEnterobacteriaceae. This technology will allow for improvedin vivoanalysis of bacterial pathogens.

Sign in / Sign up

Export Citation Format

Share Document