scholarly journals Cold-adapted bacterial extracts as a source of anti-infective and antimicrobial compounds against Staphylococcus aureus

2019 ◽  
Vol 14 (16) ◽  
pp. 1369-1382 ◽  
Author(s):  
Marco Artini ◽  
Rosanna Papa ◽  
Gianluca Vrenna ◽  
Concetta Lauro ◽  
Annarita Ricciardelli ◽  
...  

Aim: The dramatic emergence of antibiotic resistance has directed the interest of research toward the discovery of novel antimicrobial molecules. In this context, cold-adapted marine bacteria living in polar regions represent an untapped reservoir of biodiversity endowed with an interesting chemical repertoire. The aim of this work was to identify new antimicrobials and/or antibiofilm molecules produced by cold-adapted bacteria. Materials & methods: Organic extracts obtained from polar marine bacteria were tested against Staphylococcus aureus. Most promising samples were subjected to suitable purification strategies. Results: Results obtained led to the identification of a novel lipopeptide able to effectively inhibit the biofilm formation of S. aureus. Conclusion: New lipopeptide may be potentially useful in a wide variety of biotechnological and medical applications.

2012 ◽  
Vol 60 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Osman Tel ◽  
Özkan Aslantaş ◽  
Oktay Keskin ◽  
Ebru Yilmaz ◽  
Cemil Demir

In this study,Staphylococcus aureusstrains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilmforming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried theblaZ and 8 (7.2%) theermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried theicaA andicaD genes but none of them harboured thebapgene. The results demonstrated thatS. aureusisolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of theS. aureusisolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.


2021 ◽  
Vol 50 (3) ◽  
pp. 433-441
Author(s):  
D. Aksoy

AbstractIn this study, microbiological quality of 93 ready-to-eat food products was determined by enumeration of total aerobic bacteria and members of Enterobacteriaceae. Presence of Staphylococcus aureus and Listeria monocytogenes in the products were also investigated. Aerobic colony counts were between 1.9 × 102–3.4 × 108 CFU g−1 for 84.9% and Enterobacteriaceae counts were between 2 × 102 and 6.7 × 106 CFU g−1 for 43% of the samples. S. aureus was detected in 7.5% of the samples, but L. monocytogenes was not detected in any sample. 72.9% of the Enterobacteriaceae isolates showed resistance to at least one antibiotic tested, and 5 among the S. aureus isolates were found to be resistant to penicillin G and 2 against methicillin. Four S. aureus isolates produced only Staphylococcal enterotoxin A and 1 isolate produced both Staphylococcal enterotoxin A and B. Biofilm experiments revealed biofilm formation on polystyrene for 95.8%, 87.5%, and 91.6% of Enterobacteriaceae isolates at 4 °C, 22 °C, and 37 °C, respectively, whereas all S. aureus isolates formed biofilm at all temperatures.


2014 ◽  
Vol 8 (12) ◽  
pp. 1511-1517 ◽  
Author(s):  
Solmaz Ohadian Moghadam ◽  
Mohammad Reza Pourmand ◽  
Farzaneh Aminharati

Introduction: Burns are the most serious forms of trauma and a major cause of mortality worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common pathogens of burn wound infections; treatment has faced serious problems due to antibiotic resistance in these strains. Biofilm formation, which increases antibiotic resistance capabilities and is considered to be a virulence factor, also causes treatment failure and recurrent staphylococcal infections in burn patients. Methodology: A total of 135 pus/wound swabs were collected; S. aureus was identified by confirmatory tests. The icaA/D and mecA genes were detected in DNA extracts by polymerase chain reaction assay separately. To determine the prevalence of biofilm formation, a modified Congo red agar and the microtiter plate method were used. Investigation of antibiotic resistance was performed using the disk diffusion method. Results: S. aureus (48.87%) was identified in 65 (48.87%) samples, of which 40 (61.53%) were confirmed to be MRSA. Among MRSA and methicillin-sensitive S. aureus (MSSA) isolates, 97.5% and 60% produced biofilm, respectively. Resistance of MRSA isolates to amikacin, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, mupirocin, rifampin, tetracycline, and tobramycin was 64.1%, 76.92%, 51.28%, 87.18%, 71.8%, 10.26%, 5.13%, 89.74%, and 61.54%, respectively. All MRSA and MSSA isolates were susceptible to fusidic acid, linezolid, teicoplanin, tigecycline, and vancomycin. Conclusions: The high prevalence of biofilm-producing, drug-resistant S. aureus isolates in our study suggests that epidemiological studies on the characteristics of common strains found in burn centers and a definition of their antibiotic resistance pattern would be helpful for therapeutic decisions.


Sign in / Sign up

Export Citation Format

Share Document