Virulence Factor Genes in Staphylococcus aureus Isolated From Diabetic Foot Soft Tissue and Bone Infections

2018 ◽  
Vol 17 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Gerardo Víquez-Molina ◽  
Javier Aragón-Sánchez ◽  
Cristian Pérez-Corrales ◽  
Christian Murillo-Vargas ◽  
María Eugenia López-Valverde ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Virulence Factors ◽  
Diabetic Foot ◽  
Meca Gene ◽  
Cross Sectional Study ◽  
Beta Lactam ◽  
Cross Sectional ◽  
Bone Infections ◽  
Genes Encoding

The aim of this study is to describe the presence of genes encoding for 4 virulence factors (pvl, eta, etb, and tsst), as well as the mecA gene conferring resistance to beta-lactam antibiotics, in patients with diabetes and a staphylococcal foot infection. We have also analyzed whether isolates of Staphylococcus aureus from bone infections have a different profile for these genes compared with those from exclusively soft tissue infections. In this cross-sectional study of a prospectively recruited series of patients admitted to the Diabetic Foot Unit, San Juan de Dios Hospital, San José, Costa Rica with a moderate or severe diabetic foot infection (DFI), we collected samples from infected soft tissue and from bone during debridement. During the study period (June 1, 2014 to May 31, 2016), we treated 379 patients for a DFI. S aureus was isolated from 101 wound samples, of which 43 were polymicrobial infections; we only included the 58 infections that were monomicrobial S aureus for this study. Infections were exclusively soft tissue in 17 patients (29.3%) while 41 (70.7%) had bone involvement (osteomyelitis). The mecA gene was detected in 35 cases (60.3%), pvl gene in 4 cases (6.9%), and tsst gene in 3 (5.2%). We did not detect etA and etB in any of the cases. There were no differences in the profile of S aureus genes encoding for virulence factors (pvl, etA, etB, and tsst) recovered from DFIs between those with just soft tissue compared to those with osteomyelitis. However, we found a significantly higher prevalence of pvl+ strains of S aureus associated with soft tissue compared with bone infections. Furthermore, we observed a significantly longer time to healing among patients infected with mecA+ (methicillin-resistant) S aureus (MRSA).

scholarly journals Toxin production and drug resistance profiles of pediatric methicillin-resistant Staphylococcus aureus isolates in Tehran

2017 ◽  
Vol 11 (10) ◽  
pp. 759-765 ◽  
Author(s):  
Mozhgan Esmaeili Benvidi ◽  
Hamidreza Houri ◽  
Zohreh Ghalavand ◽  
Bahram Nikmanesh ◽  
Hadi Azimi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Toxin Production ◽  
Cross Sectional Study ◽  
Biochemical Tests ◽  
Cross Sectional ◽  
Methicillin Resistant ◽  
Present Cross Sectional Study ◽  
Invasive Diseases

Introduction: Staphylococcus aureus is known to be a major cause of skin and soft tissue infections, pneumonia and invasive diseases. In this study, attempts were made to examine the prevalence of tsst-1, eta, etb, and luk-PV genes among methicillin-resistant S. aureus (MRSA) isolated from children in Tehran. Methodology: In the present cross-sectional study, a total of 100 MRSA were isolated from children who were referred to a pediatric hospital during 11-month period of September 2014 to August 2015. Isolates were identified using biochemical tests and then, using PCR, the isolates were tested for the presence of mecA, tsst-1, eta, etb, and luk-PV genes. Susceptibility of isolates to cefoxitin, penicillin, erythromycin, clindamycin, gentamicin, rifampin, minocycline, co-trimoxazole, linezolid, and vancomycin were evaluated using standard methods. Results: It was found that the MRSA isolates had the greatest resistance to clindamycin (72%) and erythromycin (59%), while the lowest rates of resistance were observed to be related to minocycline (6%) and rifampin (12%). All of isolates were sensitive to vancomycin and linezolid. The mecA gene was detected in all the isolates. Moreover, luk-PV and tsst-1 were detected in 18% and 17% of the isolates, respectively. None of the isolates harbored eta and etb genes. Conclusions: Our data provide specifications about the toxin production status of S. aureus isolates from pediatric children. The current study showed increased resistance to different antibiotics in S. aureus isolates. Therefore, to prevent multi-resistance to other antibiotic classes, it is essential to withhold prescriptions and stop unessential use of available antibiotics.

scholarly journals Antibacterial effects of vancomycin in combination with methicillin against methicillin-resistant and methicillinsensitive Staphylococcus aureus

2019 ◽  
Vol 21 (2) ◽  
pp. 57-63 ◽  
Author(s):  
Ali Abdolahi ◽  
Alireza Khodavandi
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Mechanisms ◽  
Meca Gene ◽  
Antibacterial Activities ◽  
Cross Sectional Study ◽  
Clinical Samples ◽  
Synergistic Activity ◽  
Cross Sectional ◽  
Methicillin Resistant

Background and aims: Staphylococcus aureus is considered as a frequent cause of infections. Therefore, antibacterial agents including β-lactam are normally used to treat these infections while the emergence of antibiotic resistance is one of the major clinical problems in this respect. Accordingly, combination antibacterial therapy is one way to alleviate this problem. As a result, the present study aimed to investigate the combined effects of vancomycin and methicillin on clinical isolates of methicillin-resistant S. aureus (MRSA) and methicillinsensitive S. aureus (MSSA). In addition, a series of follow-up studies were performed to evaluate the antibacterial activity. Methods: The current cross-sectional study was conducted on 40 hospitalized patients from various clinical samples such as pus/wound swabs, blood, urine and sputum during a 6-month period in 2017. To this end, the antibacterial activities of vancomycin and methicillin, alone and in combination were investigated against MRSA and MSSA. Eventually, the inhibitory effects of vancomycin and methicillin alone and in combination were studied on the growth profile of MRSA and MSSA, as well as the expression of mecA gene. Results: Based on the results, the significant synergistic and partial synergistic activity with fractional inhibitory concentration (FIC) and fractional bactericidal concentration (FBC) indexes ranged from 0.27-0.938 and 0.313-0.844, respectively, in the combination of vancomycin and methicillin in MRSA and MSSA isolates. Further, the obtained data indicated that the combination of vancomycin and methicillin had a synergistic effect against MRSA isolates (P<0.01). The expression levels of the mecA gene were down-regulated by 5.25- fold in the combination of vancomycin and methicillin in MRSA isolate (P<0.001). Conclusion: In general, these events may reflect the potential uses of vancomycin and methicillin combination against MRSA. However, a greater understanding of the underlying molecular mechanisms of vancomycin and methicillin in combination could contribute to the development of therapeutic strategies.

scholarly journals Ready-to-eat foods: A potential vehicle for spread of coagulase-positive staphylococci and antibiotic-resistant Staphylococcus aureus in Buea municipality, South West Cameroon

2021 ◽  
Author(s):  
Seraphine Nkie Esemu ◽  
Sally Tabe Njoh ◽  
Lucy M. Ndip ◽  
Nene Kaah Keneh ◽  
Jerome Achah Kfusi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Meca Gene ◽  
Microbiological Quality ◽  
Cross Sectional Study ◽  
Food Samples ◽  
Cross Sectional ◽  
Antibiotic Resistant ◽  
Enterotoxin Genes ◽  
Susceptibility Profiles ◽  
Coagulase Positive Staphylococci

Background The consumption of ready-to-eat (RTE) foods contaminated with coagulase-positive staphylococci (CoPS) and especially Staphylococcus aureus puts consumers at potential risk of foodborne disease or colonization and subsequent infection. This cross-sectional study determined the levels of CoPS and the presence of S. aureus in RTE foods sold in Buea municipality. Method A total of 420 RTE food samples comprising 70 each of cake, bread, fruit salad, meat-hot-pot, suya and boiled rice were randomly purchased from February to August 2020. The CoPS counts were determined by culturing on Baird-Parker agar and S. aureus identified by amplification of the nuc gene using polymerase chain reaction. All S. aureus isolates were screened for the presence of classical staphylococcal enterotoxin genes and each isolate challenged with 11 antibiotics to determine their antibiotic susceptibility profiles. Oxacillin-resistant S. aureus were analyzed for the presence of mecA gene. Result Overall, 161 (38.3%) samples had detectable levels of coagulase-positive staphylococci ranging from 2.0-5.81 log10CFU/g. Based on CoPS levels, 37 (8.81%) of the 420 RTE food samples, only fruit salad and meat-hot-pot, had unsatisfactory microbiological quality. A total of 72 S. aureus isolates, comprising 52.78% from fruit salad, 16.67% from meat-hot-pot, 12.5% from boiled rice, 9.72% from suya, 5.56% from bread and 4.17% from cake were recovered. None of the S. aureus isolates possessed any of the classical enterotoxin genes. All the isolates were sensitive to vancomycin and ofloxacin while 68 (94.44%) and 66 (91.67%) were sensitive to oxacillin and ciprofloxacin, respectively. Resistance to penicillin (93.06%) was highest followed by amoxicillin (91.67%) and erythromycin (79.17%). Four isolates were identified as methicillin-resistant S. aureus all of which carried the mecA gene. A total of 24 antibiotypes were identified. Conclusion Our findings showed that RTE foods sold in the Buea municipality are likely vehicles for transmission of CoPS and antibiotic-resistant S. aureus.

scholarly journals Distribution of Genes Encoding Virulence Factors of Shigella Strains Isolated from Children with Diarrhea in Southwest Iran.

2020 ◽  
Author(s):  
maryam Afzali ◽  
nabi jomehzadeh ◽  
khadijeh ahmadi
Keyword(s):  
Virulence Factors ◽  
Virulence Genes ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Chain Reaction ◽  
Cross Sectional ◽  
Genes Encoding ◽  
Baseline Information ◽  
Polymerase Chain ◽  
Southwest Iran

Abstract Background: This study aimed to investigate the distribution of virulence factor genes in Shigella strains isolated from children with diarrhea in the southwest, Iran.Methods: In this cross-sectional study, a total of 91 Shigella spp. were isolated from diarrhea specimens of 1 530 children aged under 15 years in Ahvaz and Abadan, southwest Iran. The Shigella strains were identified by biochemical methods. Subsequently, Shigella spp. were identified by polymerase chain reaction (PCR).All Shigella spp evaluated by PCR for the presence of 9 virulence genes (ipaH, ial, virF, invE, sat, sigA, pic, pet, and sepA).Results: A total of 91 isolates including 47 S. flexneri, 36 S. sonnei, and 8 S. boydii were identified. All isolates were positive for the ipaH gene. The other genes include ial, virF, invE, sigA, sat, sepA, pic and pet found in 84.6%, 72.5%,68.1%, 62.6%, 51.6%, 39.5%, 37.3% and 28.5% of the isolates, respectively.Conclusion: Our results showed a high distribution of virulence genes among Shigella strains in our region. It seems that for different Shigella spp. different virulence factors contribute to pathogenesis. The current study provided insights into some baseline information about the distribution of some virulence genes of Shigella isolates in Southwest Iran.

scholarly journals Panton Valentine Gene in both Community-acquired and Healthcare-acquired Methicillin Resistant Staphylococcus aureus Isolates from Ain Shams University Hospitals

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
R A Mohamed ◽  
L F Fathi ◽  
N N Salaheldeen
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Meca Gene ◽  
Cross Sectional Study ◽  
P Value ◽  
University Hospitals ◽  
Cross Sectional ◽  
Mannitol Salt Agar ◽  
Methicillin Resistant

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen that is associated with both hospital and community infections. Panton Valentine leukocidin (PVL) is an important virulence factor of S. aureus that is considered by many authors a marker of community acquired MRSA (CA-MRSA). Aim of the Work This study aimed to determine the prevalence of PVL genes among healthcare acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) and CA-MRSA isolates, and to test the hypothesis that PVL is a reliable marker of CA-MRSA isolates. Material and Methods This comparative cross-sectional study was done on fifteen community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) and fifteen hospital acquired methicillin resistant Staphylococcus aureus (HA-MRSA), obtained from patients attending outpatient clinics, presenting with community-acquired pyogenic infections and patients with healthcare acquired pyogenic infections in Intensive Care Units (ICUs), during the period from May 2017 till February 2018. Clinical specimens included pus and different body fluids. Staphylococcus aureus was isolated and identified using conventional microbiological methods3. Isolates were then tested for methicillin resistance by culture on mannitol salt agar (MSA) with cefoxitin4. The presence of mecA and pvl genes in all MRSA isolates was subsequently detected by PCR5,6. Results Among 15 HA-MRSA isolates, mecA gene was positive in 40% (6/15) of isolates, while pvl gene was positive in 53.3% (8/15) of isolates. Among 15 CA-MRSA isolates, mecA gene was positive in 46.7% (7/15) of isolates, while pvl gene was positive in 26.7% (4/15) of isolates. Conclusion We conclude that pvl gene is not a sole genetic marker for diagnosis CA-MRSA, as there was no significant correlation between mecA that encodes for methicillin resistance and pvl genes among fifteen CA-MRSA isolates (P value =1).

Suppurative Infections in Hospitalized Patients – An Ongoing MRSA Threat

2020 ◽  
Author(s):  
Sadaf Razzak
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Science ◽  
Great Influence ◽  
Antibiotic Sensitivity ◽  
Skin Lesions ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Inducible Clindamycin Resistance ◽  
Empiric Antibiotic ◽  
Medical Wards

Background: Penicillin resistance among Staphylococcus aureus commonly encountered in the hospital admitted patients. Detection of antibiotic sensitivity in hospital acquired methicillin resistant Staphylococcus aureus infections is important as it has great influence on empiric antibiotic prescription, successful control of infection, prevention of spread of disease and successful patient management. This study aimed to detect the frequency of HA-MRSA from pus samples in a hospital setup with assessment of their antibiotic susceptibility patterns. Method: A cross-sectional study was conducted in the Microbiology department of Basic Medical Science Institute, JPMC, Karachi from January 2015 until December 2015. Pus samples from surgical site wounds, skin lesions, abscesses from surgical and medical wards and ICUs were collected. According to the standards given by CLSI 2014, MRSA testing of the samples was done and susceptibility testing for antibiotics was performed. Inducible clindamycin resistance was detected by D-Test; E Test. determined MIC (minimum inhibitory concentration) for vancomycin. The data was analyzed by SPSS version 16. Result: Out of the 149 MRSA identified from the pus samples, 106 (71.14%) samples were HA-MRSA. The number of male patients was more than the female patients (67.66%). Out of the 106 HA-MRSA, 91(85.8%) were sensitive to TMP/SMX, 98(92.5%) to rifampicin, 12(11.6%) to gentamicin, 85(80.2%) to tetracycline, 11(10.4%) to erythromycin, 37(34.9%) to clindamycin, 20(18.9%) to ciprofloxacin, 106 (100%) to both vancomycin and linezolid. Conclusion: HA-MRSA showed sensitivity to TMP/SMX and vancomycin making them effective drugs to use in combination in superficial infections. The drug linezolid also showed 100% sensitivity.

Clinical Utility of the Ankle-Brachial Index and Toe Brachial Index in Patients with Diabetic Foot Ulcers

2020 ◽  
Vol 16 (3) ◽  
pp. 270-277 ◽  
Author(s):  
Mutasem Ababneh ◽  
Mousab Y. Al Ayed ◽  
Asirvatham A. Robert ◽  
Mohamed A. Al Dawish
Keyword(s):  
Diabetic Foot ◽  
Statistical Significance ◽  
Ankle Brachial Index ◽  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Arterial Disease ◽  
Cross Sectional Study ◽  
Screening Tests ◽  
Cross Sectional ◽  
Toe Brachial Index

Background: This cross sectional study investigated the clinical use of the ankle-brachial index (ABI) and toe brachial index (TBI) in 91 type 2 diabetic foot ulcer patients who visited the diabetic foot clinic, Prince Sultan Military Medical City, Saudi Arabia during July 2017 and January 2018. Materials and Methods: The ABI and TBI facilitated the detection of peripheral arterial disease (PAD) and the patients’ medical records were used to collect the clinical and demographic variables. The variables of duration (p = 0.047) and treatment (p = 0.046) of the ABI showed significant differences. Age (p = 0.034) and duration (p = 0.001) were the factors related to the diagnosis of TBI by the “χ2” test. Results: From the TBI, 26.4% of the patients were found to have PAD, while the ABI showed that 21.8% of patients had the condition. However, no statistical significance was noted. From the regression analysis, the variable duration of diabetes (≥ 20 years of age) was recognized as an independent risk factor for TBI. Conclusion: In conclusion, it is recommended both the ABI and TBI to be used as screening tests for PAD in diabetic foot ulcer patients.

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