scholarly journals THE CONFIGURATION OF GLUTAMIC AND ASPARTIC ACIDS FROM PATHOGENIC BACTERIA (PHYTOMONAS TUMEFACIENS AND CORYNEBACTERIUM DIPHTHERIÆ)

1939 ◽  
Vol 130 (1) ◽  
pp. 29-33
Author(s):  
Erwin Chargaff
Keyword(s):  
Pathogenic Bacteria ◽  
Corynebacterium Diphtheriae

scholarly journals Induction and Resuscitation of Viable but Nonculturable Corynebacterium diphtheriae

2021 ◽  
Vol 9 (5) ◽  
pp. 927
Author(s):  
Takashi Hamabata ◽  
Mitsutoshi Senoh ◽  
Masaaki Iwaki ◽  
Ayae Nishiyama ◽  
Akihiko Yamamoto ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Diphtheria Toxin ◽  
Pathogenic Bacteria ◽  
Corynebacterium Diphtheriae ◽  
Human Pathogen ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Environmental Survival ◽  
Reverse Transcription Quantitative Pcr ◽  
Morphological Differences

Many pathogenic bacteria, including Escherichia coli and Vibrio cholerae, can become viable but nonculturable (VBNC) following exposure to specific stress conditions. Corynebacterium diphtheriae, a known human pathogen causing diphtheria, has not previously been shown to enter the VBNC state. Here, we report that C. diphtheriae can become VBNC when exposed to low temperatures. Morphological differences in culturable and VBNC C. diphtheriae were examined using scanning electron microscopy. Culturable cells presented with a typical rod-shape, whereas VBNC cells showed a distorted shape with an expanded center. Cells could be transitioned from VBNC to culturable following treatment with catalase. This was further evaluated via RNA sequence-based transcriptomic analysis and reverse-transcription quantitative PCR of culturable, VBNC, and resuscitated VBNC cells following catalase treatment. As expected, many genes showed different behavior by resuscitation. The expression of both the diphtheria toxin and the repressor of diphtheria toxin genes remained largely unchanged under all four conditions (culturable, VBNC, VBNC after the addition of catalase, and resuscitated cells). This is the first study to demonstrate that C. diphtheriae can enter a VBNC state and that it can be rescued from this state via the addition of catalase. This study helps to expand our general understanding of VBNC, the pathogenicity of VBNC C. diphtheriae, and its environmental survival strategy.

Analysis of the Manganese and MntR Regulon in Corynebacterium diphtheriae

2021 ◽  
Author(s):  
Eric D. Peng ◽  
Lindsey R. Lyman ◽  
Michael P. Schmitt
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Pathogenic Bacteria ◽  
Expression Profiles ◽  
Cadmium Toxicity ◽  
Corynebacterium Diphtheriae ◽  
Uptake System ◽  
Dependent Manner ◽  
Wild Type ◽  
Binding Studies

Corynebacterium diphtheriae is the causative agent of a severe respiratory disease in humans. The bacterial systems required for infection are poorly understood, but the acquisition of metals such as manganese (Mn) is likely critical for host colonization. MntR is a Mn-dependent transcriptional regulator in C. diphtheriae that represses the expression of the mntABCD genes, which encode a putative ABC metal transporter. However, other targets of Mn and MntR regulation in C. diphtheriae have not been identified. In this study, we use comparisons between the gene expression profiles of wild-type C. diphtheriae strain 1737 grown without or with Mn supplementation and comparisons of gene expression between wild-type and an mntR deletion mutant to characterize the C. diphtheriae Mn and MntR regulon. MntR was observed to both repress and induce various target genes in a Mn-dependent manner. Genes induced by MntR include the Mn-superoxide dismutase, sodA , and the putative ABC transporter locus, iutABCD . DNA binding studies showed that MntR interacts with the promoter regions for several genes identified in the expression study, and a 17-bp consensus MntR DNA binding site was identified. We found that an mntR mutant displayed increased sensitivity to Mn and cadmium that could be alleviated by the additional deletion of the mntABCD transport locus, providing evidence that the MntABCD transporter functions as a Mn uptake system in C. diphtheriae . The findings in this study further our understanding of metal uptake systems and global metal regulatory networks in this important human pathogen. Importance Mechanisms for metal scavenging are critical to the survival and success of bacterial pathogens, including Corynebacterium diphtheriae . Metal import systems in pathogenic bacteria have been studied as possible vaccine components due to high conservation, critical functionality, and surface localization. In this study, we expand our understanding of the genes controlled by the global manganese regulator, MntR. We determined a role for the MntABCD transporter in manganese import using evidence from manganese and cadmium toxicity assays. Understanding the nutritional requirements of C. diphtheriae and the tools used to acquire essential metals will aid in the development of future vaccines.

Probiotic Displaces Pathogenic Bacteria

2006 ◽  
Vol 37 (7) ◽  
pp. 48
Author(s):  
ERIK GOLDMAN
Keyword(s):  
Pathogenic Bacteria

Iron and Malaria: Absorption, Efficacy and Safety

2010 ◽  
Vol 80 (45) ◽  
pp. 279-292 ◽  
Author(s):  
Richard Hurrell
Keyword(s):  
Pathogenic Bacteria ◽  
Intestinal Barrier ◽  
Systemic Circulation ◽  
Malarial Parasite ◽  
Asymptomatic Malaria ◽  
Iron Supplements ◽  
Fortified Food ◽  
Care Giving ◽  
Single Meal ◽  
Women And Children

Febrile malaria and asymptomatic malaria parasitemia substantially decrease iron absorption in single-meal, stable isotope studies in women and children, but to date there is no evidence of decreased efficacy of iron-fortified foods in malaria-endemic regions. Without inadequate malarial surveillance or health care, giving iron supplements to children in areas of high transmission could increase morbidity and mortality. The most likely explanation is the appearance of non-transferrin-bound iron (NTBI) in the plasma. NTBI forms when the rate of iron influx into the plasma exceeds the rate of iron binding to transferrin. Two studies in women have reported substantially increased NTBI with the ingestion of iron supplements. Our studies confirm this, but found no significant increase in NTBI on consumption of iron-fortified food. It seems likely that the malarial parasite in hepatocytes can utilize NTBI, but it cannot do so in infected erythrocytes. NTBI however may increase the sequestration of parasite-infected erythrocytes in capillaries. Bacteremia is common in children with severe malaria and sequestration in villi capillaries could lead to a breaching of the intestinal barrier, allowing the passage of pathogenic bacteria into the systemic circulation. This is especially important as frequent high iron doses increase the number of pathogens in the intestine at the expense of the barrier bacteria.

Susceptibility of animal pathogenic bacteria to an ethanolic extract from jambolan (Syzygium cumini) leaves

Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
AL Magalhães ◽  
G Melo ◽  
N Gabriel ◽  
G Gabas ◽  
G Gonçalves ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Ethanolic Extract ◽  
Syzygium Cumini

Analysis of Coliform and Colifecal Total Pollution Test on Various Types of Drinking Water Using the MPN (Most Probable Number) Method

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Wanda Aulya ◽  
Fadhliani Fadhliani ◽  
Vivi Mardina
Keyword(s):  
Drinking Water ◽  
Fecal Coliform ◽  
Pathogenic Bacteria ◽  
Microbiological Quality ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Inspection Method ◽  
Sample Number ◽  
Probable Number ◽  
Fecal Coliform Bacteria

Water is the main source for life and also the most severe substance caused by pollution. The mandatory parameters for determining microbiological quality of drinking water are total non-fecal Coliform bacteria and Coliform fecal (Escherichia coli). Coliform bacteria are a group of microorganisms commonly used as indicators, where these bacteria can be a signal to determine whether a water source has been contaminated by bacteria or not, while fecal Coliform bacteria are indicator bacteria polluting pathogenic bacteria originating from human feces and warm-blooded animals (mammals) . The water inspection method in this study uses the MPN (Most Probable Number) method which consists of 3 tests, namely, the presumption test, the affirmation test, and the reinforcement test. The results showed that of 15 drinking water samples 8 samples were tested positive for Coliform bacteria with the highest total bacterial value of sample number 1, 15 (210/100 ml), while 7 other samples were negative. From 8 positive Coliform samples only 1 sample was stated to be negative fecal Coliform bacteria and 7 other samples were positive for Coliform fecal bacteria with the highest total bacterial value of sample number 1 (210/100 ml).

Sign in / Sign up

Export Citation Format

Share Document