scholarly journals Transferrins Reduce Replication of Chlamydia suis in McCoy Cells

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 858
Author(s):  
Leentje De Puysseleyr ◽  
Kristien De Puysseleyr ◽  
Joanna Rybarczyk ◽  
Paulien Vander Donck ◽  
Winnok De Vos ◽  
...  
Keyword(s):  
Culture Medium ◽  
Inclusion Size ◽  
Bovine Lactoferrin ◽  
Intestinal Infections ◽  
Chlamydia Suis ◽  
Resistant Strains ◽  
Boar Semen ◽  
Bacterial Replication ◽  
Egg Components ◽  
Venereal Transmission

Chlamydia suis (C. suis) resides in the intestines of pigs and tetracycline-resistant strains are emerging worldwide. Intestinal infections are often subclinical. However, the gut is regarded as a C. suis reservoir and clinical infections have been associated with enteritis, conjunctivitis, pneumonia and reproductive failure. C. suis was found in boar semen and venereal transmission occurred. We studied the anti-Chlamydia suis activity of ovotransferrin (ovoTF) and bovine lactoferrin (bLF). Pre-incubation of C. suis with bLF or ovoTF had no significant effect on overall chlamydia replication (mean fluorescence area) in McCoy cells. The addition of ovoTF to the culture medium had no effect on bacterial replication, but the addition of 0.5 or 5 mg/mL of bLF significantly reduced the inclusion size by 17% and 15% respectively. Egg components are used for cryopreservation of boar semen. When inoculating an ovoTF-containing and Chlamydia suis-spiked semen sample in McCoy cells, a significant reduction in inclusion number (by 7%) and overall replication (by 11%) was observed. Thus, we showed that transferrins possess anti-chlamydial activity. Moreover, ovoTF addition to semen extenders might reduce C. suis venereal transmission. Further research is needed to unravel the mechanisms behind the observations and to enhance the effect of transferrins on C. suis.

scholarly journals Using Isothiazolone Biocides to Control Microbial and Fungal Contaminants in Plant Tissue Cultures

1998 ◽  
Vol 8 (4) ◽  
pp. 598-601 ◽  
Author(s):  
Randall P. Niedz
Keyword(s):  
Tissue Culture ◽  
Plant Growth ◽  
Plant Tissue ◽  
Culture Medium ◽  
Tissue Cultures ◽  
Fungal Contamination ◽  
Plant Tissue Cultures ◽  
Resistant Strains ◽  
Microbial Contaminants ◽  
Fungal Contaminants

Controlling bacterial and fungal contamination in plant tissue cultures is a serious problem. Antibiotics are currently used but are not always effective, can alter plant growth, and are costly, and resistant strains can result with extensive use. Plant preservative mixture (PPM) contains a mixture of two isothiazolones—methylchloroisothiazolinone and methylisothiazolinone, which are a class of broad-spectrum, widely used industrial biocides. The isothiazolones used in PPM are reported by the manufacturer to be nonphytotoxic at concentrations suitable for the prophylactic control of microbial contaminants in plant tissue cultures. Our results indicate that PPM can be routinely added to tissue culture medium to control air- and waterborne bacterial and fungal contaminants effectively.

scholarly journals Bovine Lactoferrin Pre-Treatment Induces Intracellular Killing of AIEC LF82 and Reduces Bacteria-Induced DNA Damage in Differentiated Human Enterocytes

2019 ◽  
Vol 20 (22) ◽  
pp. 5666 ◽  
Author(s):  
Maria Stefania Lepanto ◽  
Luigi Rosa ◽  
Antimo Cutone ◽  
Mellani Jinnett Scotti ◽  
Antonietta Lucia Conte ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cellular Localization ◽  
Culture Medium ◽  
Intracellular Survival ◽  
Bovine Lactoferrin ◽  
Natural Immunity ◽  
Cell Surface Molecule ◽  
Dna Damages ◽  
Pre Treatment ◽  
The Moment

LF82, a prototype of adherent-invasive E. coli (AIEC), is able to adhere to, invade, survive and replicate into intestinal epithelial cells. LF82 is able to enhance either its adhesion and invasion by up-regulating carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM-6), the main cell surface molecule for bacterial adhesion, and its intracellular survival by inducing host DNA damage, thus blocking the cellular cycle. Lactoferrin (Lf) is a multifunctional cationic glycoprotein of natural immunity, exerting an anti-invasive activity against LF82 when added to Caco-2 cells at the moment of infection. Here, the infection of 12 h Lf pre-treated Caco-2 cells was carried out at a time of 0 or 3 or 10 h after Lf removal from culture medium. The effect of Lf pre-treatment on LF82 invasiveness, survival, cell DNA damage, CEACAM-6 expression, apoptosis induction, as well as on Lf subcellular localization, has been evaluated. Lf, even if removed from culture medium, reduced LF82 invasion and survival as well as bacteria-induced DNA damage in Caco-2 cells independently from induction of apoptosis, modulation of CEACAM-6 expression and Lf sub-cellular localization. At our knowledge, this is the first study showing that the sole Lf pre-treatment can activate protective intracellular pathways, reducing LF82 invasiveness, intracellular survival and cell–DNA damages.

Effect of bovine lactoferrin on the minimum inhibitory concentrations of ampicillin and trimethoprim–sulfamethoxazole for clinical Shigella spp. strains1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal’s usual peer review process.

2012 ◽  
Vol 90 (3) ◽  
pp. 412-416 ◽  
Author(s):  
Susan Mosquito ◽  
Gianina Zegarra ◽  
Claudia Villanueva ◽  
Joaquin Ruiz ◽  
Theresa J. Ochoa
Keyword(s):  
Peer Review Process ◽  
Shigella Flexneri ◽  
Shigella Dysenteriae ◽  
In Vivo Studies ◽  
Bovine Lactoferrin ◽  
Shigella Boydii ◽  
Microdilution Method ◽  
Shigella Spp ◽  
Resistant Strains

Here, we determined the effect of bovine lactoferrin (bLF) on the minimum inhibitory concentration (MIC) of ampicillin and trimethoprim–sulfamethoxazole in Shigella . Using a microdilution method, the MIC was determined in the presence or absence of bovine lactoferrin (10 mg/mL) on 88 Shigella strains (56 Shigella flexneri , 15 Shigella boydii , 13 Shigella sonnei , and 4 Shigella dysenteriae ) previously isolated from peruvian children <2 years old. A fold change of 2 or more in MIC values was considered significant. For ampicillin, 67 (76%) strains were highly resistant; one-third of the strains (32%) showed a decrease in ampicillin MIC in the presence of LF. This was more typical of MIC values in less resistant strains. For 7 (8%) ampicillin-resistant strains, the decrease in the MIC resulted in the strains reaching the cutoff for susceptible in the presence of bLF. For trimethoprim–sulfamethoxazole, 93% of the isolates (n = 82) were highly resistant and only 4 isolates (5%) decreased their MIC in the presence of bLF. None of the trimethoprim–sulfamethoxazole resistant strains became susceptible in the presence of LF. The decrease in the MIC in the presence of bLF seems to depend on the mechanisms of action of each antibiotic. In vivo studies are needed to further evaluate bLF as a coadjuvant to antibiotic treatment of resistant Shigella.

scholarly journals Mode of origin of sulphonamide-resistant strains inB. dysenteriaeFlexner

1947 ◽  
Vol 45 (1) ◽  
pp. 28-32 ◽  
Author(s):  
F. H. Stewart
Keyword(s):  
Resistant Strain ◽  
Culture Medium ◽  
Coliform Bacteria ◽  
Chemical Stimulus ◽  
Resistant Strains ◽  
Free Media

The change by which a strain ofB. dysenteriaeFlexner becomes resistant to sulphonamides is similar in character to the change inB. coli mutabilefrom white (non-lactose-fermenting) to red (lactosefermenting).The highest proportion of variants are found in papillae, while no variants are found in the growing margin of colonies.Reversion does not take place during growth on sulphonamide-free media.The variation is a direct and heritable response to a chemical stimulus and in adaptation to this part of the environment.The variation described by Reiner Müller ofB. typhosuson rhamnose and of certain coliform bacteria on arabinose may also be of the same nature.Strains ofB. dysenteriaeFlexner resistant to sulphanilamide or sulphaguanidine 1/10,000 are only partially resistant to sulphathiazole 1/100,000 and to sodium sulphapyridine 1/10,000.Technique. The size of (uncrowded) colonies on a plate containing 1/10,000 sulphanilamide or sodium sulphacetamide is a useful criterion of resistance or non-resistance, but a resistant strain must be able to grow on 1/5000 Sa and will not grow on 1/5000 Ssac.The best culture medium for these tests is Lab. Lemco bouillon with agar, but without peptone.In concluding I wish to express my thanks for their help to Prof. H. R. Dean, Prof. C. H. Browning, Drs E. T. C. Spooner, A. MacDonald, J. E. McCartney and R. D. Stuart. The sulphonamides I received through the kindness of the British Pharmacopoeial Commission and of Messrs May and Baker.

scholarly journals Symbiotic effectiveness and ecological characterization of indigenous Rhizobium loti populations in Uruguay

1999 ◽  
Vol 34 (6) ◽  
pp. 1010-1017 ◽  
Author(s):  
Amalia Baraibar ◽  
Llillian Frioni ◽  
Maria Elena Guedes ◽  
Hans Ljunggren
Keyword(s):  
Culture Medium ◽  
Indigenous Populations ◽  
Symbiotic Effectiveness ◽  
Symbiotic Efficiency ◽  
Rhizobium Loti ◽  
Acid Tolerant ◽  
Resistant Strains ◽  
Lotus Pedunculatus ◽  
Tolerance Factors

The objectives of this work were to describe the distribution, density and seasonal variation of the indigenous populations of Rhizobium loti in different Uruguayan soils and to determine the symbiotic effectiveness and stress tolerance factors of different isolates, both with the aim of obtaining selected strains to re-introduce as inoculants in Lotus pastures. R. loti was present in ten soils studied and their densities varied from year to year and within each soil. All the isolates nodulated Lotus corniculatus effectively. The nodules in Lotus pedunculatus and Lotus subbiflorus were small, red on the surface and ineffective in nitrogen fixation. The study of 50 isolates from the ten soils showed high variability in their symbiotic efficiency and tolerance to pH. The indigenous population was acid tolerant in culture medium (pH 4.5), 83% of them could grow at pH 4.5 in 3 days. This work showed that there was a great diversity between the strains of R. loti isolated from Uruguayan soils and supports the importance of selecting among them the most efficient and resistant strains to be included in the inoculants.

Inactivation of Listeria monocytogenes by Lactoferricin, a Potent Antimicrobial Peptide Derived from Cow's Milk

1992 ◽  
Vol 55 (4) ◽  
pp. 238-240 ◽  
Author(s):  
HIROYUKI WAKABAYASHI ◽  
WAYNE BELLAMY ◽  
MITSUNORI TAKASE ◽  
MAMORU TOMITA
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Peptide ◽  
Culture Medium ◽  
Complete Inhibition ◽  
Cow’S Milk ◽  
Bovine Lactoferrin ◽  
Rapid Loss ◽  
Cow's Milk ◽  
Low Concentrations ◽  
Ph Range

The susceptibility of Listeria monocytogenes to inhibition and inactivation by lactoferricin, a newly isolated antimicrobial peptide derived from bovine lactoferrin present in cow's milk, was studied in laboratory media. Lactoferricin showed an effectiveness similar to that of many clinically useful antibiotics, causing complete inhibition of four strains of L. monocytogenes (serotypes 1b, 2, 3, and 4a) at low concentrations varying within the range of 0.3 to 9 μg/ml depending on the strain and the culture medium used. The effectiveness of lactoferricin against L. monocytogenes was not strongly affected by the presence of various carbohydrates or proteins but was somewhat diminished in the presence of various salts. The peptide showed potent activity over the pH range of 5.5 to 7.5. The effect of lactoferricin was lethal, causing a rapid loss of colony-forming ability with all four strains tested.

scholarly journals Intestinal Lesions Caused by a Strain of Chlamydia Suis in Weanling Pigs Infected at 21 Days of Age

2000 ◽  
Vol 12 (3) ◽  
pp. 233-239 ◽  
Author(s):  
Douglas G. Rogers ◽  
Arthur A. Andersen
Keyword(s):  
Weanling Pigs ◽  
Intestinal Lesions ◽  
Intestinal Infections ◽  
Intestinal Pathogen ◽  
Chlamydia Suis ◽  
Group 2 ◽  
Gnotobiotic Piglets ◽  
Distal Jejunum ◽  
Chlamydial Antigen ◽  
Group 1

The objective of this study was to determine whether a strain of Chlamydia suis shown previously to be an intestinal pathogen in gnotobiotic piglets could cause diarrhea and intestinal lesions in young weanling pigs. Pigs from 2 sows were randomly assigned to 2 groups. Group 1 included 13 pigs that were weaned at 24 hours of age and then housed in isolator units and fed milk replacer and unmedicated starter ration. Group 2 included 8 pigs that nursed their respective sows, consumed unmedicated starter ration, and were weaned at 21 days of age. Ten pigs in group 1 and 6 pigs in group 2 were inoculated orally with 4 × 108 inclusion-forming units of C. suis strain R27 at 21 days of age. Control pigs were inoculated with sham inoculum. The pigs were necropsied 5–14 days postinoculation (DPI). None of the Chlamydia-infected pigs developed diarrhea. Villus atrophy was seen histologically in sections of ileum from Chlamydia-infected pigs in both groups 5 and 7 days DPI. Lymphangitis and multiple lymphohistiocytic and neutrophilic aggregates were seen in the submucosa, tunica muscularis, and serosa of the distal jejunum, ileum, and colon from Chlamydia-infected pigs in both groups 5–14 DPI. Immunostaining of sections of distal jejunum, ileum, and colon from infected pigs revealed chlamydial antigen in intestinal epithelium and in foci of lymphangitis/inflammation. The results indicated that C. suis strain R27 can cause intestinal lesions in young weanling pigs, and the lesions are similar to those seen in gnotobiotic piglets. The results also indicated that strain R27 causes asymptomatic intestinal infections in young weanling pigs, at least under the conditions of this study.

scholarly journals Inhibition of Hyphal Growth of Azole-Resistant Strains of Candida albicans by Triazole Antifungal Agents in the Presence of Lactoferrin-Related Compounds

1998 ◽  
Vol 42 (7) ◽  
pp. 1587-1591 ◽  
Author(s):  
Hiroyuki Wakabayashi ◽  
Shigeru Abe ◽  
Susumu Teraguchi ◽  
Hirotoshi Hayasawa ◽  
Hideyo Yamaguchi
Keyword(s):  
Candida Albicans ◽  
Resistant Strain ◽  
Antifungal Agents ◽  
Inhibitory Concentration ◽  
Staining Method ◽  
Hyphal Growth ◽  
Bovine Lactoferrin ◽  
Resistant Strains ◽  
Related Compounds ◽  
Important Form

ABSTRACT The effects of bovine lactoferrin (LF) or the LF-derived antimicrobial peptide lactoferricin B (LFcin B) on the growth ofCandida albicans hyphae, including those of three azole-resistant strains, were investigated by a crystal violet staining method. The hyphae of two highly azole-resistant strains were more susceptible to inhibition by LF or LFcin B than the azole-susceptible strains tested. One moderately azole-resistant strain was defective in the formation of hyphae and showed a susceptibility to LF greater than that of the susceptible strains but a susceptibility to LFcin B similar to that of the susceptible strains. The highly azole-resistant strain TIMM3317 showed trailing growth in the presence of fluconazole or itraconazole, while the extent of growth was reduced by the addition of LF or LFcin B at a sub-MIC. Thus, the addition of LF or LFcin B at a sub-MIC resulted in a substantial decrease in the MICs of fluconazole and itraconazole for two highly azole-resistant strains; e.g., the MIC of fluconazole for TIMM3317 was shifted from >256 to 0.25 μg/ml by LF, but the MICs were not decreased for the susceptible strains. The combination effects observed with triazoles and LF-related compounds in the case of the two highly azole-resistant strains were confirmed to be synergistic by the fractional inhibitory concentration index. These results demonstrate that for some azole-resistant C. albicans strains, LF-related compounds combined with triazoles can inhibit the growth of hyphae, an important form of this organism in pathogenesis.

scholarly journals Characterizing the Type 6 Secretion System (T6SS) and its role in the virulence of avian pathogenic Escherichia coli strain APECO18

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12631
Author(s):  
Aline L. de Oliveira ◽  
Nicolle L. Barbieri ◽  
Darby M. Newman ◽  
Meaghan M. Young ◽  
Lisa K. Nolan ◽  
...  
Keyword(s):  
Culture Media ◽  
Coli Strain ◽  
Infection Process ◽  
Host Cells ◽  
Economic Losses ◽  
Poultry Production ◽  
E Coli ◽  
Intestinal Infections ◽  
Animal Pathogens ◽  
Bacterial Replication

Avian pathogenic E. coli is the causative agent of extra-intestinal infections in birds known as colibacillosis, which can manifest as localized or systemic infections. The disease affects all stages of poultry production, resulting in economic losses that occur due to morbidity, carcass condemnation and increased mortality of the birds. APEC strains have a diverse virulence trait repertoire, which includes virulence factors involved in adherence to and invasion of the host cells, serum resistance factors, and toxins. However, the pathogenesis of APEC infections remains to be fully elucidated. The Type 6 secretion (T6SS) system has recently gained attention due to its role in the infection process and protection of bacteria from host defenses in human and animal pathogens. Previous work has shown that T6SS components are involved in the adherence to and invasion of host cells, as well as in the formation of biofilm, and intramacrophage bacterial replication. Here, we analyzed the frequency of T6SS genes hcp, impK, evpB, vasK and icmF in a collection of APEC strains and their potential role in virulence-associated phenotypes of APECO18. The T6SS genes were found to be significantly more prevalent in APEC than in fecal E. coli isolates from healthy birds. Expression of T6SS genes was analyzed in culture media and upon contact with host cells. Mutants were generated for hcp, impK, evpB, and icmF and characterized for their impact on virulence-associated phenotypes, including adherence to and invasion of host model cells, and resistance to predation by Dictyostelium discoideum. Deletion of the aforementioned genes did not significantly affect adherence and invasion capabilities of APECO18. Deletion of hcp reduced resistance of APECO18 to predation by D. discoideum, suggesting that T6SS is involved in the virulence of APECO18.

scholarly journals Sensitization of Microcin J25-Resistant Strains by a Membrane-Permeabilizing Peptide

2010 ◽  
Vol 76 (20) ◽  
pp. 6837-6842 ◽  
Author(s):  
Mar�a Fernanda Pomares ◽  
M�nica A. Delgado ◽  
Natalia S. Corbal�n ◽  
Ricardo N. Far�as ◽  
Paula A. Vincent
Keyword(s):  
Therapeutic Agent ◽  
Gram Negative Bacteria ◽  
Outer Membrane Receptor ◽  
Independent Manner ◽  
E Coli ◽  
Serovar Typhimurium ◽  
Resistant Strains ◽  
Bacterial Replication ◽  
Microcin J25

ABSTRACT Microcin J25 (MccJ25) is a plasmid-encoded, 21-amino-acid, antibacterial peptide produced by Escherichia coli. MccJ25 inhibits RNA polymerase and the membrane respiratory chain. MccJ25 uptake into E. coli-sensitive strains is mediated by the outer membrane receptor FhuA and the inner membrane proteins TonB, ExbB, ExbD, and SbmA. This peptide is active on some E. coli, Salmonella, and Shigella species strains, while other Gram-negative bacteria, such as clinical isolates of Enterobacter cloacae, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Moraxella catarrhalis, and Salmonella enterica serovar Typhimurium, are completely resistant. In the present work, we demonstrated that the membrane-permeabilizing peptide (KFF)3K made some resistant strains sensitive to MccJ25, among them S. Typhimurium, where the antibiotic inhibits in vitro cell growth and bacterial replication within macrophages. The results demonstrate that the membrane permeabilization induced by (KFF)3K allows MccJ25 penetration in an FhuA and SbmA-independent manner and suggest that the combination of both peptides could be considered as a therapeutic agent against pathogenic Salmonella strains.

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