scholarly journals Bovine abortion associated with Staphylococcus aureus infection - characterization of S. aureus strain isolated from fetal tissues

2020 ◽  
Vol 50 (6) ◽  
Author(s):  
Luan Cleber Henker ◽  
Marina Paula Lorenzett ◽  
Camila Imperico Riboldi ◽  
Franciele Maboni Siqueira ◽  
David Driemeier ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Fetal Loss ◽  
Multidrug Resistant ◽  
Aureus Strain ◽  
Alpha Hemolysin ◽  
Aureus Infection ◽  
Bronchiolar Epithelium ◽  
Toxic Shock Syndrome Toxin ◽  
Bovine Abortion

ABSTRACT: Staphylococcus aureus is a gram-positive bacterium, commonly found colonizing the skin and mucous membranes of humans and animals. This report describes a case of fetal loss associated with S. aureus infection in a cow. A six-month old, crossbred male bovine fetus from a beef farm was submitted for necropsy. At gross examination fibrinous pleuropneumonia was observed. Histologically, lesions were restricted to the lungs and consisted of marked multifocal to coalescing areas of inflammatory infiltrate of neutrophils, abundant fibrin exudation, necrosis of bronchiolar epithelium and numerous aggregates of coccoid bacteria. Lung and abomasal fluid bacterial culture yielded pure culture of S. aureus, which was characterized as a multidrug resistant strain. Molecular analysis indicated that the studied strain presented several genes of virulence factors including toxic shock syndrome toxin-1 (tst), staphylococcal enterotoxin type A (sea), Panton-Valentine leukocidin (pvl), alpha-hemolysin (hla) and delta-hemolysin (hld). This report documents an infrequent case of fetal loss in cattle due to infection with a highly virulent S. aureus strain.

Membrane mutations and production of enterotoxin B and alpha hemolysin in Staphylococcus aureus

1975 ◽  
Vol 21 (3) ◽  
pp. 275-280 ◽  
Author(s):  
Robert A. Altenbern
Keyword(s):  
Staphylococcus Aureus ◽  
Aureus Strain ◽  
Type B ◽  
Alpha Hemolysin ◽  
Osmotic Stability ◽  
Enterotoxin B

Staphylococcus aureus strain S-6, which produces enterotoxin type B (SEB), and strain 10-275, a high toxin-producing mutant derived from S-6, display pronounced differences in dye sensitivity, osmotic stability, and bacitracin sensitivity. Such characteristics are consistent with the concept that strain 10-275 is a membrane mutant of strain S-6. Some membrane mutants of S. aureus strain 14458 exhibit about two- to three-fold increases in SEB production whereas other membrane mutants show about twofold increases in α-hemolysin production. It is suggested that specific and independent membrane mutations control the secretory processes resulting in the extracellular elaboration of these exoproteins.

scholarly journals Characterization of a Catalase-Negative Methicillin-Resistant Staphylococcus aureus Strain

2007 ◽  
Vol 45 (8) ◽  
pp. 2684-2685 ◽  
Author(s):  
B. M. Gruner ◽  
S.-R. Han ◽  
H.-G. Meyer ◽  
U. Wulf ◽  
S. Bhakdi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Aureus Strain ◽  
Methicillin Resistant

scholarly journals JD419, a Staphylococcus aureus Phage With a Unique Morphology and Broad Host Range

2021 ◽  
Vol 12 ◽  
Author(s):  
Tingting Feng ◽  
Sebastian Leptihn ◽  
Ke Dong ◽  
Belinda Loh ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Host Range ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Complete Characterization ◽  
Resistant Bacteria ◽  
Broad Host Range ◽  
Gene Engineering ◽  
Mrsa Strains

Phage therapy represents a possible treatment option to cure infections caused by multidrug-resistant bacteria, including methicillin and vancomycin-resistant Staphylococcus aureus, to which most antibiotics have become ineffective. In the present study, we report the isolation and complete characterization of a novel phage named JD219 exhibiting a broad host range able to infect 61 of 138 clinical strains of S. aureus tested, which included MRSA strains as well. The phage JD419 exhibits a unique morphology with an elongated capsid and a flexible tail. To evaluate the potential of JD419 to be used as a therapeutic phage, we tested the ability of the phage particles to remain infectious after treatment exceeding physiological pH or temperature. The activity was retained at pH values of 6.0–8.0 and below 50°C. As phages can contain virulence genes, JD419’s complete genome was sequenced. The 45509 bp genome is predicted to contain 65 ORFs, none of which show homology to any known virulence or antibiotic resistance genes. Genome analysis indicates that JD419 is a temperate phage, despite observing rapid replication and lysis of host strains. Following the recent advances in synthetic biology, JD419 can be modified by gene engineering to remove prophage-related genes, preventing potential lysogeny, in order to be deployed as a therapeutic phage.

scholarly journals Isolation and Genetic Characterization of Vancomycin-resistant and mecC+ Methicillin-resistant Staphylococcus aureus Strains in Clinical Samples of Bojnurd, Northeastern Iran

2021 ◽  
Vol 14 (10) ◽  
Author(s):  
Parastoo Zarghami Moghaddam ◽  
Amir Azimian ◽  
Abbas Akhavan Sepahy ◽  
Alireza Iranbakhsh
Keyword(s):  
Staphylococcus Aureus ◽  
Tertiary Hospital ◽  
Clinical Samples ◽  
Spa Typing ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Alpha Hemolysin ◽  
Pcr Method ◽  
Vancomycin Resistant

Background: The emergence of antibiotic-resistant Staphylococcus aureus strains is one of the major concerns about the various staphylococcal infections. Vancomycin is one the most important effective antibiotics on staphylococcal lethal infections. To date, vancomycin-resistant strains are increasingly isolated in different parts of the world, and it is alerting. Objectives: The current study was designed to evaluate the prevalence, and antibiotic susceptibility pattern of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) isolates in the main tertiary hospital of Bojnurd, Iran. Methods: S. aureus isolates were collected from different clinical samples in Imam Reza Hospital of Bojnurd. After identification of isolates through using conventional methods, they were evaluated by agar screening, disk diffusion, and minimum inhibitory concentration (MIC) methods to determine resistance to vancomycin and methicillin. We also performed polymerase chain reaction (PCR) for the detection of mecA, mecC, vanA, and vanB genes. After confirmation of vancomycin resistance, genetic analysis was performed using SCCmec, agr, and spa typing, and multilocus sequence typing (MLST) methods on VRSA isolates. Results: We found four vancomycin-resistant isolates (1.29%). Also, 75% of isolates were resistant to cefoxitin. Using the PCR method, mecA was found in 73%, mecC in 0.64%, and vanA in 1.29% of isolates. Interestingly, we found two mecC positive isolates in MRSA isolates. The alpha-hemolysin (81.81%) and enterotoxin C (27%) had the highest and lowest toxins percentage, respectively. Among mecA positive isolates, SCCmecIV (37%), SCCmecIII (31.27%), SCCmecI (14%), SCCmecII (11%), and SCCmecV (5.7%) were the most prevalent SCCmec types, respectively. It should be noted that the two mecC positive isolates belonged to SCCmecXI. AgrI (76.29%) was the highest agr type. We recognized t037 as the dominant spa type, and ST239, ST6, ST97, and ST8 were found in VRSA isolates. Conclusions: In our study, the frequency of mecA genes in MRSA isolates was very high. It seems that the resistant isolates belonged to endemic clones of Iran.

Functional Characterization of Type III-A CRISPR-Cas in a Clinical Human Methicillin-R Staphylococcus aureus Strain

2021 ◽  
Author(s):  
Yang Li ◽  
Kasper Mikkelsen ◽  
Oleguer Lluch i Grané ◽  
Zhenyu Wang ◽  
Yuanyue Tang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Functional Characterization ◽  
Aureus Strain ◽  
Type Iii
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