جستجوی مقالات مرتبط با کلیدواژه « coagulase » در نشریات گروه « پزشکی »

Staphylococcus aureus causes problems in hospitals and it has emerged as a serious agent acquired from the environment in recent years. One of the capabilities of S. aureus is the formation of biofilms, in which bacteria can exchange antibiotic-resistance genes among themselves and increase the virulence of other strains of this species (S. aureus). A surface protein attached to the cell wall in S. aureus clumping factor A is a virulence factor in various staphylococcal infections.

In this study, after the Urea Analysis (UA) test, the urea culture test was applied to the blood agar and Baird-Parker Agar culture media from the infectious urine samples in Imam Hospital, Tehran, to identify S. aureus isolates. Finally, a molecular method was used for the confirmation of identified isolates. The microliter plate method was performed to determine the biofilm formation ability. The disk diffusion method was also used for profiling the antibiotic resistance of the isolates.

In the results of this study, 45 out of 160 urinary clinical samples were positive for S. aureus, among which 42 isolates expressed the clfA gene. Moreover, 39 isolates had the ability to form biofilms in vitro. Among these 42 isolates, the highest (88%) and the lowest (16%) rates of antibiotic resistance were observed against penicillin and cefoxitin, respectively. Data analysis with SPSS software and chi-square indicated a significant relationship between gene expression and biofilm production with antibiotic resistance (P < 0.05).

The resistance of S. aureus bacteria is increasing strongly due to the repeated use of antibiotics such as beta-lactams, especially in respiratory infections and pharyngitis. Moreover, biofilm formation and virulence factors, such as clfA and clfB, cause concerns to the World Health Organization for treatment, especially for people with sepsis or toxemia.

Coagulase-negative staphylococci (CoNS) are rolled in severe infections in animals and nosocomial infections in humans. Given that staphylococci other than Staphylococcus aureus are often reported only as CoNS in medical diagnosis laboratories, this study aimed to determine the exact species of this type of staphylococci in clinical samples.

This study also aimed to evaluate antibiotic resistance, the ability to carry cfr, qacA/B, mecA, and vanA genes, and the diversity of staphylococcal cassette chromosome mec (SCCmec) elements in mecA-carrying isolates.

Staphylococcus spp. strains were isolated from the blood samples of children admitted to Imam Reza Hospital in Bojnurd, Northeastern Iran, between 2013 - 2019. All CoNS isolates were evaluated for resistance to vancomycin and oxacillin using agar screening and other routine anti-CoNS antibiotics using the Kirby-Bauer disk diffusion method, based on the latest Clinical and Laboratory Standards Institute guidelines. The CoNS strains were isolated based on conventional methods and polymerase chain reaction (PCR)-restriction fragment length polymorphism. The PCR was applied to determine the diversity of SCCmec elements in the CoNS isolates.

In this study, 203 isolates were confirmed as CoNS belonging to nine staphylococci spp. S. capitis and S. epidermidis were the top two common CoNS. Type III was the dominant SCCmec type in mecA+ isolates.

The findings of this study showed that CoNS isolated from blood cultures have a relatively high diversity and antibiotic resistance. Therefore, further attention should be paid to the isolation of these strains in laboratories, and they should not be easily considered as contamination.

Staphylococcus aureus is considered a major cause of food poisoning in the world. We aimed to investigate the prevalence of S. aureus isolated from hamburgers in Kashan city.

In this study, 71 hamburger samples were collected from supermarkets in Kashan from March to July 2017. The samples were examined after dilution in the Baird–Parker Agar Base medium of inoculation for the bacterial growth of S. aureus. Gram staining, catalase tests, mannitol fermentation, coagulase, DNase, and sensitivity to novobiocin were used to detect the bacteria.

The collected hamburgers were about eight types of products. Of the total samples, 15 (21.13%) were Gram‑positive bacteria contaminated, including seven cocci and eight bacilli. Seven samples (9.86%) of hamburgers were contaminated with S. aureus. The average counts of S. aureus in positive samples were 1.94 × 103 colony‑forming unit (CFU)/g.

The outbreak of S. aureus isolates in meat products, particularly hamburger, is of serious threat to public health. To prevent the outbreak of this pathogen in hamburgers, permanent control and monitoring should be performed in food industries.