Methicillin-Susceptible, Vancomycin-Resistant Staphylococcus aureus, Brazil

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Panesso , Diana; Planet , Paul J.; Diaz , Lorena; Hugonnet , Jean-Emannuel; Tran , Truc T.; Narechania , Apurva; Munita , José M.; Rincon , Sandra; Carvajal , Lina P.; Reyes , Jinnethe; Londono , Alejandra; Smith , Hannah; Sebra , Robert; Deikus , Gintaras; Weinstock , George M

2015-01-01

International audience; We report characterization of a methicillin-susceptible, vancomycin-resistant bloodstream isolate of Staphylococcus aureus recovered from a patient in Brazil. Emergence of vancomycin resistance in methicillin-susceptible S. aureus would indicate that this resistance trait might be poised to disseminate more rapidly among S. aureus and represents a major public health threat.

Modulation of the norfloxacin resistance in Staphylococcus aureus by Cordia verbenaceae DC

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Edinardo F.F Matias; Karla K. A Santos; Vivyanne S Falcão-Silva; José P Siqueira-Júnior; José G. M Costa; Henrique D.M Coutinho

2013-01-01

Background & objectives: Several chemical compounds isolated from natural sources have antibacterial activity and some enhance the antibacterial activity of antibiotics reversing the natural resistance of bacteria to certain antibiotics. In this study, the hexane and methanol extract of Cordia verbenaceae were assessed for antibacterial activity alone and combinated with norfloxacin against the Staphylococcus aureus strain SA1199B. Methods: The minimum inhibitory concentration (MIC) of ex...

Characterization of multiple antibiotic resistant clinical strains of Staphylococcus isolated from pregnant women vagina.

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Hetsa, Bakwena Ashton; Kumar, Ajay; Ateba, Collins Njie

2018-03-29

Vagina which is one of the important reservoirs for Staphylococcus and in pregnant women pathogenic strains may infect the child during the birth or by vertical transmission. A total of 68 presumptive Staphylococcus strains isolated from human vagina were found to be gram-positive cocci, and only 32 (47%) isolates were found beta-hemolytic. Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) results confirmed 33 isolates belonged to Staphylococcus which consisting of 6 species, i.e., S. aureus (14), S. vitulinus (7), S. epidermidis (4), S cohnii (3), S. equorum (3), and S. succinus (2). Further, the result of antibiotic susceptibility tests showed that large proportions (76%-100%) of the isolates were resistant to multiple antibiotics and more often resistant to penicillin (100%), ampicillin (100%), oxacillin (97%), oxytetracycline (97%), vancomycin (97%), rifampin (85%), erythromycin (82%), and streptomycin (76%). In the present study, only the sec enterotoxin gene was detected in four S. aureus strains. DNA fingerprints of the 33 isolates that were generated using random amplified polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC) PCR analysis revealed great genetic relatedness of isolates. High prevalence of vaginal colonization with multiple antibiotic-resistant staphylococci among pregnant women was observed which were emerged from the single respective species clones that underwent evolution. The vertical transmission of these multiple antibiotic-resistant Staphylococcus species to the infant is possible; therefore, the findings of this study emphasize the need for regular surveillance of antibiotic-resistant bacterial strains in pregnant women in this area.

Methicillin-resistant Staphylococcus aureus prevalence: Current susceptibility patterns in Trinidad

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Land Michael

2006-05-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become one of the most widespread causes of nosocomial infections worldwide. Recently, reports have emerged that S. aureus strains recovered from community-acquired infections are also methicillin-resistant. This study was undertaken to analyze the prevalence of methicillin resistance among isolates at a regional hospital in Trinidad, and document the current resistance profile of MRSA and methicillin-sensitive Staphylococcus aureus (MSSA to the commonly used anti-staphylococcal agents. Methods Over a 6-year period we analyzed 2430 isolates of S. aureus strains recovered from various clinical sources, from hospital and community practices. Antimicrobial susceptibility testing was done according to guideline recommendations of the National Committee for Clinical Laboratory Standards. Results The prevalence of MRSA from surgical/burn wounds, urine and pus/abscess were 60.1%, 15.5% and 6.6%, respectively. The major sources of MSSA were surgical/burn wounds, pus/abscess and upper respiratory tract specimens with rates of 32.9%, 17.1% and 14.3%, respectively. The greatest prevalence of resistance of MRSA was seen for erythromycin (86.7%, and clindamycin (75.3%. Resistance rates among MSSA were highest for ampicillin (70%. Resistance rates for tetracycline were similar among both MRSA (78.7% and MSSA (73.5%. The MRSA recovery rates from nosocomial sources (20.8% was significantly higher than that of previous years (12.5% (p Conclusion The prevalence of MRSA in the hospital increased from 12.5% in 1999 to 20.8% in 2004. Most isolates were associated with infected surgical/burn wounds which may have become infected via the hands of HCPs during dressing exercises. Infection control measures aimed at the proper hand hygiene procedures may interrupt the spread of MRSA. HCPs may also be carriers of MRSA in their anterior nares. Surveillance cultures of both patients and HCPs may help

Combination of silver nanoparticles and Drosera binata extract as a possible alternative for antibiotic treatment of burn wound infections caused by resistant Staphylococcus aureus.

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Krychowiak, Marta; Grinholc, Mariusz; Banasiuk, Rafal; Krauze-Baranowska, Miroslawa; Głód, Daniel; Kawiak, Anna; Królicka, Aleksandra

2014-01-01

Staphylococcus aureus is the most common infectious agent involved in the development of skin infections that are associated with antibiotic resistance, such as burn wounds. As drug resistance is a growing problem it is essential to establish novel antimicrobials. Currently, antibiotic resistance in bacteria is successfully controlled by multi-drug therapies. Here we demonstrate that secondary metabolites present in the extract obtained from Drosera binata in vitro cultures are effective antibacterial agents against S. aureus grown in planktonic culture and in biofilm. Moreover, this is the first report demonstrating the synergistic interaction between the D. binata extract and silver nanoparticles (AgNPs), which results in the spectacular enhancement of the observed bactericidal activity, while having no cytotoxic effects on human keratinocytes. Simultaneous use of these two agents in significantly reduced quantities produces the same effect, i.e. by killing 99.9% of bacteria in inoculum or eradicating the staphylococcal biofilm, as higher amounts of the agents used individually. Our data indicates that combining AgNPs with either the D. binata extract or with its pure compound (3-chloroplumbagin) may provide a safe and highly effective alternative to commonly used antibiotics, which are ineffective towards the antibiotic-resistant S. aureus.

Antibiotic sensitivity pattern of Staphylococcus aureus from clinical isolates in a tertiary health institution in Kano, Northwestern Nigeria

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Nwankwo Emmanuel Onwubiko

2011-01-01

Full Text Available BACKGROUND: The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern. It has a remarkable capability of evolving different mechanisms of resistance to most antimicrobial agents. The aim of the present study is to establish the incidence of S. aureus in clinical specimens and its antibiotic sensitivity pattern to various antibiotics in this locality. METHODS: One hundred and fifty consecutive isolates of S. aureus obtained from various clinical specimens between January and December 2009 sent to the Medical Microbiology Laboratory Department of Aminu Kano Teaching Hospital (AKTH were confirmed by standard bacteriological procedures. Antibiotic sensitivity pattern was carried out by disc diffusion method. RESULTS: The age group with the highest number of isolates was (0-10yrs while wound infection had the highest frequency of S. aureus isolates (30.7% in the study. Males (62.0% were more infected than females (38.0%. The sensitivity pattern of S. aureus to the following antibiotics; Gentamicin, Amoxycillin/clavulanate, Streptomycin, Cloxacillin, Erythromycin, Chloramphenicol, Cotrimoxazole, Tetracycline, Penicillin, Ciprofloxacin, Ofloxacin, Levofloxacin, Ceftriaxone, Amoxycillin and vancomycin were 92.4%, 63.0%, 44.2%, 35.8%, 52.4%, 61.9%, 15.5%, 31.2%, 7.1%, 78.9%, 76.6%, 100%, 71.4%, 30.7% and 100% respectively. Methicillin resistant isolates were sensitive to Levofloxacin 93.7% and Ofloxacin 68.7%. CONCLUSION: The results of the present study show that the fluoroquinolones are effective in the management of Staphylococcus aureus infections including methicillin resistant strains in this environment.

Microbial Quality and Antimicrobial Resistance of Staphylococcus aureus and Escherichia coli Isolated from Traditional Ice Cream in Hamadan City, West of Iran

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Ghadimi

2016-10-01

Full Text Available Background Foodborne diseases are one of the most major public health concerns in the world. Ice cream flavors, especially the traditional ones, have a high potential for the transmission of the pathogenic bacteria. Objectives The aim of the current study is to investigate the microbiological status and antibiotic resistance of Escherichia coli and Staphylococcus aureus isolated from traditional ice cream. Methods A total of 114 traditional ice creams were randomly collected from retail stores in Hamadan, Iran. Samples were investigated for the total bacteria count (TBC and contamination with the coliform, Enterobacteriaceae and Salmonella as well as the prevalence and antibiotic resistance of Staphylococcus aureus and Escherichia coli. Results The count of Enterobacteriaceae (89.47%, mold and yeast (50%, coliform (40.35% and TBC (28.07% of samples was higher than Iran’s standard. Salmonella was not found in all samples. The prevalence of Staphylococcus aureus and Escherichia coli was confirmed in 50% and 37.72% of samples, respectively. Collected Escherichia coli had the highest antibiotic resistance to ampicillin 67.44%, nalidixic acid 39.53% and co-amoxyclav 37.21%. Staphylococcus aureus showed a higher antibiotic resistance to penicillin (82.46% of isolates and oxacillin (38% of isolates. Conclusions The results showed high contamination levels of traditional ice cream with spoilage and pathogenic microorganisms as well as considerable resistance of isolated Staphylococcus aureus and Escherichia coli to common antibiotics. Therefore, good hygienic practice during processing and personal hygiene should be considered to improve the quality of ice cream. In addition, it is necessary that the regulatory authorities carry out more control on the production centers of traditional ice cream.

Plasmid profiles and antibiotic susceptibility patterns of Staphylococcus aureus isolates from Nigeria.

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Olukoya, D K; Asielue, J O; Olasupo, N A; Ikea, J K

1995-06-01

In an investigation into the problems of infections due to Staphylococcus aureus in Nigeria, 100 strains were isolated from various hospitals in Lagos. The strains were screened for the presence of plasmids and for susceptibility to antimicrobial agents. Plasmids were extracted by modification of the method of Takahashi and Nagono[1]. The plasmids were diverse in nature. The strains were found to be highly resistant to commonly prescribed antibiotics.

Treatment of methicillin-resistant Staphylococcus aureus in Latin America

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Carlos M Luna

Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin America

Antibiotic activity of the extract of Punica granatum Linn. over bovine strains of Staphylococcus aureus

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Maria A. R. Silva

Full Text Available Human and veterinary medicines have not been so well succeeded in order to achieving their goals concerning the treatment of infections for long term caused by Staphylococcus aureus linked to resistance development against antibiotic agents. The antibiotic activity of the Punica granatum Linn. fresh fruit pericarp extract was evaluated by the agar diffusion method on 38 S. aureus strains, isolated from apparently healthy lactating cows in farms situated in counties of the semi-arid region of the State of Paraíba, Brazil to determine the minimum inhibitory concentration (MIC. Twenty-two of the thirty-eight strains are penicillin-resistant (PRSA. The extract of P. granatum presented potential antibiotic action over all the assayed strains, forming 10 to 36 mm diameter inhibition zones. This paper's results claim the effectiveness of the extract of P. granatum as a potential antibacterial agent on S. aureus, and display the significance of evaluating new substances with antimicrobial potential, which can contribute to alternative therapeutics for veterinary and medicine.

VanA and VanB Positive Vancomycin-resistant Staphylococcus aureus Among Clinical Isolates in Shiraz, South of Iran

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Sareh Saadat

2014-09-01

Full Text Available Objective: The purpose of this study was to determine the prevalence of vancomycin-resistant Staphylococcus aureus isolated from clinical samples in Shiraz hospitals. Methods: From March to December 2012, 100 S. aureus isolates (mainly from wound and blood were collected from three hospitals in Shiraz, south of Iran. After identification of Staphylococcus aureus by biochemical, microbiological and molecular methods, antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion test for 13 different antibiotics. Vancomycin-resistant Staphylococcus aureus isolates were determined by vancomycin agar screening test and PCR for vancomycin resistant genes (vanA and vanB. Results: The lowest and highest resistance was seen for quinupristin-dalfopristin (n=1 and ampicillin (n=95, respectively. Vancomycin agar screening test showed that 37 isolates can grow on these media. Further study by PCR also detected vanA and/or vanB genes in all of these strains. Also, 19 isolates showed either vanA or vanB but were susceptible according to vancomycin agar screening test. In total, vanA and vanB resistant genes were detected in 34% and 37% of clinical isolates, respectively. Conclusion: The results showed that the frequency of vancomycin resistance genes (vanA, vanB is very high in Staphylococcus aureus strains isolated from patients in south of Iran. Thus, urgent interventions are needed to keep the emergence and transmission of these isolates to a minimum.

Phenotypic and genotypic evaluation of fluoroquinolone resistance in clinical isolates of Staphylococcus aureus in Tehran.

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Aligholi, Marzieh; Mirsalehian, Akbar; Halimi, Shahnaz; Imaneini, Hossein; Taherikalani, Morovat; Jabalameli, Fereshteh; Asadollahi, Parisa; Mohajer, Babak; Abdollahi, Alireza; Emaneini, Mohammad

2011-09-01

Fluoroquinolones are broad-spectrum antibiotics widely used in the treatment of bacterial infections such as Staphylococcus aureus isolates. Resistance to these antibiotics is increasing. The occurrence of mutations in the grlA and gyrA loci were evaluated in 69 fluoroquinolone-resistant S. aureus isolates from 2 teaching hospitals of Tehran University of Medical Sciences. Out of the 165 S. aureus isolates, 87 (52.7%) were resistant to methicillin and 69 (41.8%) were resistant to fluoroquinolone. Fluoroquinolone-resistant S. aureus isolates had a mutation at codon 80 in the grlA gene and different mutational combinations in the gyrA gene. These mutational combinations included 45 isolates at codons 84 and 86, 23 isolates at codons 84, 86 and 106 and 1 isolate at codons 84, 86 and 90. Fluoroquinolone-resistant S. aureus isolates were clustered into 33 PFGE types. The findings of this study show that the fluoroquinolone-resistant S. aureus strains isolated in the teaching hospitals in Tehran had multiple mutations in the QRDRs region of both grlA and gyrA genes.

Emergence of linezolid resistant Staphylococcus aureus in Bastar tribal region, India

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Mohammad Fareed Khan

2012-09-01

Full Text Available Methicillin resistant Staphylococcus aureus(MRSA is a well-known threat to the healthcaresystems for its increasing global prevalence, intrinsicability of resistance to ß-lactam and cephalosporin,and for acquiring resistance to multipleclasses of other antibiotics, causing difficult-totreatinfections with significant increase in morbidity,mortality and treatment cost. Although forsevere MRSA infections vancomycin is describedas the first-line intravenous drug, vancomycinresistantand intermediate isolates of S. aureus(VRSA & VISA have been increasingly reportedthroughout the world. The therapeutic and lifesavingoption for VRSA and VISA infections remainlinezolid, first antimicrobial of oxazolidinonegroup available since 2000. The first case of linezolid-resistant staphylococci appeared within 1year after linezolid was approved for therapeuticuse.1 Although linezolid resistance in S. aureusis uncommon, emergence has been shown fromsome parts of the world.2 From India, first casereport of linezolid resistance was published in2011 from Kashmir.3 This is the first report fromthe Chattisgarh state in Central India where wefound two linezolid-resistant Staphylococcus aureusisolates which were cultured in March 2011from pus samples collected from the male surgicalward of Maharani Hospital, Jagdalpur, Bastar.

The use of machine learning methodologies to analyse antibiotic and biocide susceptibility in Staphylococcus aureus.

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Joana Rosado Coelho

Full Text Available BACKGROUND: The rise of antibiotic resistance in pathogenic bacteria is a significant problem for the treatment of infectious diseases. Resistance is usually selected by the antibiotic itself; however, biocides might also co-select for resistance to antibiotics. Although resistance to biocides is poorly defined, different in vitro studies have shown that mutants presenting low susceptibility to biocides also have reduced susceptibility to antibiotics. However, studies with natural bacterial isolates are more limited and there are no clear conclusions as to whether the use of biocides results in the development of multidrug resistant bacteria. METHODS: The main goal is to perform an unbiased blind-based evaluation of the relationship between antibiotic and biocide reduced susceptibility in natural isolates of Staphylococcus aureus. One of the largest data sets ever studied comprising 1632 human clinical isolates of S. aureus originated worldwide was analysed. The phenotypic characterization of 13 antibiotics and 4 biocides was performed for all the strains. Complex links between reduced susceptibility to biocides and antibiotics are difficult to elucidate using the standard statistical approaches in phenotypic data. Therefore, machine learning techniques were applied to explore the data. RESULTS: In this pioneer study, we demonstrated that reduced susceptibility to two common biocides, chlorhexidine and benzalkonium chloride, which belong to different structural families, is associated to multidrug resistance. We have consistently found that a minimum inhibitory concentration greater than 2 mg/L for both biocides is related to antibiotic non-susceptibility in S. aureus. CONCLUSIONS: Two important results emerged from our work, one methodological and one other with relevance in the field of antibiotic resistance. We could not conclude on whether the use of antibiotics selects for biocide resistance or vice versa. However, the observation of

Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among industrial hog operation workers in North Carolina over 14 days.

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Nadimpalli, Maya; Rinsky, Jessica L; Wing, Steve; Hall, Devon; Stewart, Jill; Larsen, Jesper; Nachman, Keeve E; Love, Dave C; Pierce, Elizabeth; Pisanic, Nora; Strelitz, Jean; Harduar-Morano, Laurel; Heaney, Christopher D

2015-02-01

This study aimed to evaluate the persistence of nasal carriage of Staphylococcus aureus, methicillin-resistant S. aureus and multidrug-resistant S. aureus over 14 days of follow-up among industrial hog operation workers in North Carolina. Workers anticipating at least 24 h away from work were enrolled June-August 2012. Participants self-collected a nasal swab and completed a study journal on the evening of day 1, and each morning and evening on days 2-7 and 14 of the study. S. aureus isolated from nasal swabs were assessed for antibiotic susceptibility, spa type and absence of the scn gene. Livestock association was defined by absence of scn. Twenty-two workers provided 327 samples. S. aureus carriage end points did not change with time away from work (mean 49 h; range >0-96 h). Ten workers were persistent and six were intermittent carriers of livestock-associated S. aureus. Six workers were persistent and three intermittent carriers of livestock-associated multidrug-resistant S. aureus. One worker persistently carried livestock-associated methicillin-resistant S. aureus. Six workers were non-carriers of livestock-associated S. aureus. Eighty-two per cent of livestock-associated S. aureus demonstrated resistance to tetracycline. A majority of livestock-associated S. aureus isolates (n=169) were CC398 (68%) while 31% were CC9. No CC398 and one CC9 isolate was detected among scn-positive isolates. Nasal carriage of livestock-associated S. aureus, multidrug-resistant S. aureus and methicillin-resistant S. aureus can persist among industrial hog operation workers over a 14-day period, which included up to 96 h away from work. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan.

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Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

2017-01-01

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

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Dagmar Chudobova

2014-03-01

Full Text Available There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health.

Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

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Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

2014-01-01

There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

Recombinant Endolysins as Potential Therapeutics against Antibiotic-Resistant Staphylococcus aureus: Current Status of Research and Novel Delivery Strategies.

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Haddad Kashani, Hamed; Schmelcher, Mathias; Sabzalipoor, Hamed; Seyed Hosseini, Elahe; Moniri, Rezvan

2018-01-01

Staphylococcus aureus is one of the most common pathogens of humans and animals, where it frequently colonizes skin and mucosal membranes. It is of major clinical importance as a nosocomial pathogen and causative agent of a wide array of diseases. Multidrug-resistant strains have become increasingly prevalent and represent a leading cause of morbidity and mortality. For this reason, novel strategies to combat multidrug-resistant pathogens are urgently needed. Bacteriophage-derived enzymes, so-called endolysins, and other peptidoglycan hydrolases with the ability to disrupt cell walls represent possible alternatives to conventional antibiotics. These lytic enzymes confer a high degree of host specificity and could potentially replace or be utilized in combination with antibiotics, with the aim to specifically treat infections caused by Gram-positive drug-resistant bacterial pathogens such as methicillin-resistant S. aureus . LysK is one of the best-characterized endolysins with activity against multiple staphylococcal species. Various approaches to further enhance the antibacterial efficacy and applicability of endolysins have been demonstrated. These approaches include the construction of recombinant endolysin derivatives and the development of novel delivery strategies for various applications, such as the production of endolysins in lactic acid bacteria and their conjugation to nanoparticles. These novel strategies are a major focus of this review. Copyright © 2017 American Society for Microbiology.

Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

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Boopathy, Raj

2017-09-01

The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among industrial hog operation workers in North Carolina over 14 days

Science.gov (United States)

Nadimpalli, Maya; Rinsky, Jessica L; Wing, Steve; Hall, Devon; Stewart, Jill; Larsen, Jesper; Nachman, Keeve E; Love, Dave C; Pierce, Elizabeth; Pisanic, Nora; Strelitz, Jean; Harduar-Morano, Laurel; Heaney, Christopher D

2015-01-01

Objectives This study aimed to evaluate the persistence of nasal carriage of Staphylococcus aureus, methicillin-resistant S. aureus and multidrug-resistant S. aureus over 14 days of follow-up among industrial hog operation workers in North Carolina. Methods Workers anticipating at least 24 h away from work were enrolled June–August 2012. Participants self-collected a nasal swab and completed a study journal on the evening of day 1, and each morning and evening on days 2–7 and 14 of the study. S. aureus isolated from nasal swabs were assessed for antibiotic susceptibility, spa type and absence of the scn gene. Livestock association was defined by absence of scn. Results Twenty-two workers provided 327 samples. S. aureus carriage end points did not change with time away from work (mean 49 h; range >0–96 h). Ten workers were persistent and six were intermittent carriers of livestock-associated S. aureus. Six workers were persistent and three intermittent carriers of livestock-associated multidrug-resistant S. aureus. One worker persistently carried livestock-associated methicillin-resistant S. aureus. Six workers were non-carriers of livestock-associated S. aureus. Eighty-two per cent of livestock-associated S. aureus demonstrated resistance to tetracycline. A majority of livestock-associated S. aureus isolates (n=169) were CC398 (68%) while 31% were CC9. No CC398 and one CC9 isolate was detected among scn-positive isolates. Conclusions Nasal carriage of livestock-associated S. aureus, multidrug-resistant S. aureus and methicillin-resistant S. aureus can persist among industrial hog operation workers over a 14-day period, which included up to 96 h away from work. PMID:25200855

Variability of antibiotic susceptibility and toxin production of Staphylococcus aureus strains isolated from skin, soft tissue, and bone related infections

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Sina, Haziz; Ahoyo, Theodora A.; Moussaoui, Wardi; Keller, Daniel; Bankole, Honore S.; Barogui, Yves; Stienstra, Ymkje; Kotchoni, Simeon O.; Prevost, Gilles; Baba-Moussa, Lamine

2013-01-01

Background: Staphylococcus aureus is an opportunistic commensal bacterium that mostly colonizes the skin and soft tissues. The pathogenicity of S. aureus is due to both its ability to resist antibiotics, and the production of toxins. Here, we characterize a group of genes responsible for toxin

Temperature Effect on the Susceptibility of Methicillin-Resistant Staphylococcus aureus to Four Different Cephalosporins

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Canawati, Hanna N.; Witte, Joyce L.; Sapico, Francisco L.

1982-01-01

Forty isolates of methicillin-resistant Staphylococcus aureus were tested for in vitro susceptibility to cephalothin, cefamandole, cefotaxime, and moxalactam, using the disk diffusion and microbroth dilution methods at incubation temperatures of 30 and 35°C. Resistance to all four antibiotics was more clearly evident at an incubation temperature of 30°C.

Root cause analysis of methicillin resistant Staphylococcus aureus bacteraemia.

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Aslam, Nadia; Mehdi, Naima; Izhar, Mateen

2015-10-01

To find the important risk factors and sources of bacteraemia in patients suffering from methicillin-resistant staphylococcus aureus bacteraemia. The descriptive study was carried out at Shaikh Zayed Hospital, Lahore, from October 2010 to August 2011. Blood cultures were processed to isolate methicillin-resistant staphylococcus aureus. A questionnaire was completed by the participating patients suffering from bacteraemia. Information about risk factors present at the time and risk factors that served as the source of bacteraemia were noted. Total 4058 blood cultures were processed and 669(16.5%) were positive. Of them, 194(29%) cultures were found to be positive for staphylococci. Out of these 194 blood cultures, coagulase-negative staphylococci were isolated from 117(60%), and 77(40%) were positive for S. aureus. Out of these 77 samples, 26(34%) were found to be methicillin-sensitive staphylococcus aureus and 51(66%) were methicillin-resistant staphylococcus aureus. The overall frequency of methicillin-resistant staphylococcus aureus was 1.25%; 7.62% out of positive blood culture; 26.28% out of total staphylococci; and 66% out of total S. aureus. As for the source of infection, central venous pressure line 11(21.6%), post-influenza pneumonia 9(17.6%), peripheral intravenous line 8(15.7%) and dialysis line 7(13.7%) were major reasons. Taking care of aseptic measures while insertion, frequent change and early removal of the central venous and dialysis lines is of critical significance.

Combination of silver nanoparticles and Drosera binata extract as a possible alternative for antibiotic treatment of burn wound infections caused by resistant Staphylococcus aureus.

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Marta Krychowiak

Full Text Available Staphylococcus aureus is the most common infectious agent involved in the development of skin infections that are associated with antibiotic resistance, such as burn wounds. As drug resistance is a growing problem it is essential to establish novel antimicrobials. Currently, antibiotic resistance in bacteria is successfully controlled by multi-drug therapies. Here we demonstrate that secondary metabolites present in the extract obtained from Drosera binata in vitro cultures are effective antibacterial agents against S. aureus grown in planktonic culture and in biofilm. Moreover, this is the first report demonstrating the synergistic interaction between the D. binata extract and silver nanoparticles (AgNPs, which results in the spectacular enhancement of the observed bactericidal activity, while having no cytotoxic effects on human keratinocytes. Simultaneous use of these two agents in significantly reduced quantities produces the same effect, i.e. by killing 99.9% of bacteria in inoculum or eradicating the staphylococcal biofilm, as higher amounts of the agents used individually. Our data indicates that combining AgNPs with either the D. binata extract or with its pure compound (3-chloroplumbagin may provide a safe and highly effective alternative to commonly used antibiotics, which are ineffective towards the antibiotic-resistant S. aureus.

Antibiotic resistance of Staphylococcus aureus isolated from enteral diets in a public hospital of Minas Gerais Resistência a antibióticos de Staphylococcus aureus isolados de dietas enterais em um hospital público de Minas Gerais

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Nélio José de Andrade

2007-10-01

Full Text Available Enteral diets constitute an excellent means for microbial growth due to its composition rich in nutrients and its time of exposure to room temperature during application. Among the pathogenic bacteria there is the Staphylococcus aureus that is an opportunist microorganism found in the humans’ mucous membrane (buccal, nasal and oral. Samples of enteral diet after application as well as of the environment used for the preparation of the diets, were collected in a public hospital in Minas Gerais and analyzed for the presence of S. aureus. The contamination by S. aureus was evidenced in 83% of the enteral diet samples. As for the environment, the values found were in conformity with APHA recommendation. The isolated strains were submitted to the evaluation of the resistance to different antibiotics. Resistance was observed for tetracycline (100%, erythromycin (90,9%, chloramphenicol (59,1%, estreptomycin (22,72%, penicillin 18,8%, vancomycin (13,63%, ampicillin (13,63%, amoxilin (9,09% and gentamicin (4,54%. Due to the versatility in the resistance development to several antibiotics the S. aureus survives in hospital environments and can be diffused among patients. Dietas enterais constituem um excelente meio para crescimento microbiano, devido à sua composição rica em nutrientes e ao tempo de exposição à temperatura ambiente durante a administração. Dentre as bactérias patogênicas que podem ser encontradas nessas dietas, cita-se o Staphylococcus aureus, microrganismo oportunista encontrado na microbiota da membrana mucosa (bucal, nasal e oral em seres humanos. Amostras de dieta enteral pós-administração e do ambiente utilizado para o seu preparo foram coletadas em um hospital público e analisadas quanto à presença de S. aureus. A contaminação foi evidenciada em 83% das amostras de dietas enterais, e, quanto ao ambiente, os valores encontrados se apresentam de acordo com a recomendação da APHA. As cepas isoladas foram

Antibiotic Resistance Among Staphylococcus aureus and Escherichia coli Isolated From Traditional and Industrial Food Samples

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Mojtaba Arslani

2017-05-01

Full Text Available Background: Foodborne diseases are one of the serious problems in the world. Every year, more than 100 million people are affected by foodborne and waterborne diseases particularly immunocompromised diseases. Objectives: The aim of the present study was to evaluate bacterial load and antibiotic resistance pattern in bacterial isolates from food samples of meat, dairy, and pastry products from west of Tehran, Iran, during April 2007 to March 2008. Materials and Methods: A total of 1625 different food samples including dairy products, meat and pastries were collected randomly from different parts of the west of Tehran. All samples were kept at 4°C. The samples were first cultured according to the standard bacteriological methods and then Staphylococcus aureus and Escherichia coli isolates were identified using standard bacteriological tests. Antimicrobial susceptibility test was performed by disk diffusion method according to Clinical & Laboratory Standards Institute (CLSI guidelines. Results: During 2007 and 2008, 2.8% and 3% of the food samples were contaminated with S. aureus. Similarly, 3.5% and 6.4% of the food samples were contaminated with E. coli. E. coli isolates were highly resistant to amikacin and cephotaxime and this resistance was increased in 2008. Similarly S. aureus isolates were resistant to ciprofloxacin, cephotaxime, gentamicin, and tetracyclin. There was no significant difference during 2007-2008. Conclusion: The rate of contamination during 2007 was 2.8% and during 2008 was 3% for S. aureus. This strain was isolated from the food samples. Further studies should be done to determine the changes of bacterial resistance pattern for various food samples. Thus, the baseline for comparison with future prospective studies should be established, enabling the determination of trends over time.

Characterization of staphylococci in urban wastewater treatment plants in Spain, with detection of methicillin resistant Staphylococcus aureus ST398

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Gómez, Paula; Lozano, Carmen; Benito, Daniel; Estepa, Vanesa; Tenorio, Carmen; Zarazaga, Myriam; Torres, Carmen

2016-01-01

The objective of this study was to determine the prevalence of Staphylococcus in urban wastewater treatment plants (UWTP) of La Rioja (Spain), and to characterize de obtained isolates. 16 wastewater samples (8 influent, 8 effluent) of six UWTPs were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base for staphylococci and methicillin-resistant Staphylococcus aureus recovery. Antimicrobial susceptibility profile was determined for 16 antibiotics and the presence of 35 antimicrobial resistance genes and 14 virulence genes by PCR. S. aureus was typed by spa, agr, and multilocus-sequence-typing, and the presence of immune-evasion-genes cluster was analyzed. Staphylococcus spp. were detected in 13 of 16 tested wastewater samples (81%), although the number of CFU/mL decreased after treatment. 40 staphylococci were recovered (1–5/sample), and 8 of them were identified as S. aureus being typed as (number of strains): spa-t011/agr-II/ST398 (1), spa-t002/agr-II/ST5 (2), spa-t3262/agr-II/ST5 (1), spa-t605/agr-II/ST126 (3), and spa-t878/agr-III/ST2849 (1). S. aureus ST398 strain was methicillin-resistant and showed a multidrug resistance phenotype. Virulence genes tst, etd, sea, sec, seg, sei, sem, sen, seo, and seu, were detected among S. aureus and only ST5 strains showed genes of immune evasion cluster. Thirty-two coagulase-negative Staphylococcus of 12 different species were recovered (number of strains): Staphylococcus equorum (7), Staphylococcus vitulinus (4), Staphylococcus lentus (4), Staphylococcus sciuri (4), Staphylococcus fleurettii (2), Staphylococcus haemolyticus (2), Staphylococcus hominis (2), Staphylococcus saprophyticus (2), Staphylococcus succinus (2), Staphylococcus capitis (1), Staphylococcus cohnii (1), and Staphylococcus epidermidis (1). Five presented a multidrug resistance phenotype. The following resistance and virulence genes were found: mecA, lnu(A), vga(A), tet(K), erm(C), msr(A)/(B), mph(C), tst, and sem. We found that

Molecular characterization of antimicrobial resistance genes against Staphylococcus aureus isolates from Trinidad and Tobago.

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Akpaka, Patrick E; Roberts, Rashida; Monecke, Stefan

Staphylococcus aureus continues to pose major public health challenges in many areas because of antibiotic resistance problems. In the Caribbean, especially Trinidad and Tobago, the challenge is not different. This study was performed to evaluate the antimicrobial resistance gene prevalence among S. aureus isolates in Trinidad and Tobago. Standard and molecular microbiological methods, including the Microscan automated system, DNA microarray and multi locus sequence typing (MLST) analysis, were performed on 309 clinical S. aureus isolates recovered from patients who were treated at three of the country's main health institutions. S. aureus exhibited susceptibilities ≥80% to eleven of the 19 antimicrobials tested against it, and these belong to the most commonly used and available antibiotics in the country. While the antibiotic to which it was most susceptible of the commonly used antibiotics was trimethoprim/sulfamethoxazole, the antibiotics to which it was least susceptible or most resistant to were ampicillin and penicillin. S. aureus isolates from the pediatric ward produced the greatest rate of susceptibility among the isolates recovered from patients admitted into hospitals, while isolates from Accident and Emergency rooms displayed the greatest susceptibilities among patients from the community. S. aureus isolates from the country did not harbor acquired resistant genes targeting clindamycin/macrolides (ermB), linezolid (cfr) or vancomycin (vanA). The blaZ gene, which is the most common beta lactam (Penicillinase) resistance mechanism for S. aureus, was observed in 88.7% of the methicillin susceptible S. aureus, while methicillin resistance mediated by the mec gene was present in 13.6%. Most of the resistance markers found in MRSA isolates were significantly associated with the ST239-MRSA-III strain in this study, and all isolates that belonged to the USA300 strain, which additionally encoded both the PVL gene and ACME cluster, belonged to CC8. Several

Epidemiology of drug resistance: The case of Staphylococcus aureus and coagulase-negative staphylococci infections Epidemiología de la resistencia bacteriana: el caso de Staphylococcus aureus y las infecciones Staphylococcus coagulasa negativas

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Ernesto Calderón-Jaimes

2002-04-01

Full Text Available Objective. To study the activity of several antibiotics against Staphylococcus spp. Material and Methods. The study included 1209 strains of Staphylococcus spp. from two institutions; Instituto Nacional de Pediatría (National Institute of Pediatrics and Hospital Infantil de México Federico Gómez (Mexico City Children's Hospital. Minimum Inhibitory Concentrations of all antibiotics were determined by the agar macrodilution technique and standard methods from the National Committee for Clinical Laboratory Standards. Results. Resistance of S. aureus was 14.2% and that of coagulase-negative staphylococci was 53.4%. The activity of different antibiotics is presented in detail. Conclusions. Surveillance of strains resistant to methicillin is necessary.Objetivo. Determinar la frecuencia de la resistencia a la meticilina y la actividad de varios antibióticos. Material y métodos. Se incluyeron 1 209 cepas de Staphylococcus spp. procedentes de pacientes del Instituto Nacional de Pediatría y del Hospital Infantil de México Federico Gómez. Se utilizó la técnica de dilución en placas con agar. El procedimiento e interpretación fueron acordes con lo establecido por el National Committee for Clinical Laboratory Standards. Resultados. La frecuencia de la resistencia de S. aureus fue de 14.2% y de 53.4% en los Staphylococcus coagulasa negativa. La actividad de otros antimicrobianos se presenta en el texto. Conclusiones. Es necesario vigilar continuamente la progresión de la resistencia de Staphylococcus spp. a la meticilina.

Nasal methicillin-resistant Staphylococcus aureus polymerase chain reaction: a potential use in guiding antibiotic therapy for pneumonia.

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Johnson, Jennifer A; Wright, Michael E; Sheperd, Lyndsay A; Musher, Daniel M; Dang, Bich N

2015-01-01

The role at admission of nasal polymerase chain reaction (PCR) for patients with methicillin-resistant Staphylococcus aureus (MRSA) in guiding antibiotic therapy for lower respiratory tract infection is unknown. To determine whether nasal MRSA PCR at admission can predict the absence of MRSA in lower respiratory tract secretions. We performed a retrospective study of adult patients admitted to a large urban hospital. Patients had a nasal MRSA PCR test and a lower respiratory tract culture obtained within 48 hours of admission and the culture yielded S aureus. Sensitivity, specificity, and positive and negative predictive values. Our results showed high sensitivity (93.3%) and negative predictive value (95.2%) of nasal PCR for MRSA in the lower respiratory tract. With its high sensitivity and negative predictive value, a nasal MRSA PCR test performed within 48 hours of hospital admission could help guide the discontinuation of MRSA-directed empiric antibiotic therapy in patients who are unlikely to be infected with this organism. A prospective study is needed to confirm these findings.

A genomic portrait of the emergence, evolution, and global spread of a methicillin-resistant Staphylococcus aureus pandemic

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Holden, Matthew T G; Hsu, Li-Yang; Kurt, Kevin

2013-01-01

The widespread use of antibiotics in association with high-density clinical care has driven the emergence of drug-resistant bacteria that are adapted to thrive in hospitalized patients. Of particular concern are globally disseminated methicillin-resistant Staphylococcus aureus (MRSA) clones that ...

Prevalence of antibiotic resistant Staphylococcus aureus from raw milk samples collected from the local vendors in the region of Tirupathi, India

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Sudhanthirakodi Sudhanthiramani

2015-04-01

Full Text Available Aim: The study was carried out with the aim to identify the suitability of the milk for consumer use with special reference to Staphylococcus aureus from milk samples collected from various local vendors and determine the antibiotic susceptibility pattern of those positive isolates. Materials and Methods: A total of 110 milk samples were collected from the local milk vendors in and around Tirupathi region of India. All the samples were enriched with buffered peptone water in 9:1 ratio and the then inoculated on baird parker agar medium with added 2% egg yolk tellurite emulsion as selective medium for S.aureus and confirmed with mannitol salt agar, Gram’s staining and biochemical tests. The typical cultural characters with coagulase-positive samples were taken as positive samples the positive samples were tested for antibiotic susceptibility with 10 different antibiotics by employing disc diffusion method. Results: Prevalence of coagulase-positive S. aureus was 39.09% (43/110 from the milk samples. The antibiotic susceptibility test of positive isolates showed high resistant toward penicillin G 37/43 (86.04% and ampicillin 32/43 (74.42%, and also showed resistant to methicillin 6/43 (13.95%, cephalothin 6/43 (13.95%, tetracycline 6/43 (13.95%, ciprofloxacin 4/43 (9.30%, enrofloxacin 3/43 (6.97%, cefoxitin 2/43 (4.65%, gentamicin 2/43 (4.65%, and co-trimoxazole 2/43 (4.65%. Many individual isolates showed resistant against two or more antibiotics in our study. Conclusion: The above study results show that the milk samples collected from local vendor having S. aureus, which can induce disease condition as well as antibiotic resistant to the humans particularly young children and old age peoples by means of consumption of raw milk and its products. This is the public health issue, which needs to be solved by educating the local vendors regarding health problems related to unhygienic milk supply and make the awareness among the consumers about this

Associations between resistance phenotype and gene expression in response to serial exposure to oxacillin and ciprofloxacin in Staphylococcus aureus.

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Uddin, M J; Ahn, J

2017-12-01

This study was designed to delineate the relationship between resistance phenotypes and gene expression in wild-type (SA WT ), oxacillin-induced (SA OXA ), ciprofloxacin-induced (SA CIP ) and clinically acquired antibiotic-resistant Staphylococcus aureus (SA CA ) exposed to oxacillin (β-lactam) and ciprofloxacin (fluoroquinolone). The phenotypic response and gene expression were varied with the antibiotic exposure. SA WT was highly resistant to oxacillin (MIC = 8 μg ml -1 ) after serial exposure to oxacillin, while the oxacillin susceptibility was not changed in SA WT when exposed to ciprofloxacin (MIC = 0·25 μg ml -1 ). The clinical isolate, SA CA , was highly resistant to all classes of antibiotics used in this study. The increased resistance of SA OXA and SA CIP to penicillinase-labile penicillins was attributed to the production of β-lactamase, which is in good agreement with the overexpression of blaZ (>2-fold). The overexpression of efflux pump-related genes (norA, norB, norC, mdeA, mepR, mgrA and lmrS) was associated with the increased resistance of SA CIP and SA CA to aminoglycosides and quinolones. This study confirmed that the linkage between resistance phenotypes and molecular genotypes highly varied depending on intrinsic resistance profile, response to antibiotic exposure and genes conferring resistance. This study provides useful information for understanding the mechanisms of methicillin resistance in S. aureus in association with phenotypic and genotypic resistance determinants. The improvement in current standards is essential to accurately detect methicillin-resistant Staphylococcus aureus in consideration of various resistance phenotypes and genotypes. The varied and distinctive expression patterns of antibiotic resistance-related genes were observed in S. aureus exposed to oxacillin and ciprofloxacin. It is worth noting the relationship between resistance phenotype and resistance genotype in terms of MIC values and expression of

In vitro effectiveness of triterpenoids and their synergistic effect with antibiotics against Staphylococcus aureus strains.

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Hamza, Muhammad; Nadir, Maha; Mehmood, Nadir; Farooq, Adeel

2016-01-01

The aim of this study is to evaluate the effect of four triterpenoids such as oleanolic acid, ursolic acid, cycloastragenol, and beta-boswellic acid alone and in combination with antibiotics against Staphylococcus aureus strains. Sixteen clinical strains of S. aureus from infected wounds were isolated. Eight were methicillin-sensitive S. aureus (MSSA), and the other eight were methicillin-resistant S. aureus (MRSA). The activity was also seen in reference S. aureus American Type Culture Collection ™ strains. The activity of all the triterpenoids and antibiotics against S. aureus was evaluated by broth microdilution method. The effectiveness was judged by comparing the minimum inhibitory concentrations (MICs) of the compounds with antibiotics. The combination of antibiotics with compounds was evaluated by their fractional inhibitory concentrations (FIC). Against both clinical and reference MSSA strains, none of the compounds exhibited comparable activity to antibiotics vancomycin or cefradine except for ursolic acid (MIC 7.8 μg/ml). Against MRSA, all compounds (MIC 16-128 μg/ml) showed lesser activity than vancomycin (MIC 5.8 μg/ml). Among triterpenoid-antibiotic combinations, the most effective were ursolic acid and vancomycin against clinical strain MSSA (FIC S 0.17). However, overall, different combinations between triterpenoids and antibiotics showed 95%-46% ( P antibiotics compared to when antibiotics were used alone. Cefradine, a drug not suitable for treating MRSA (MIC = 45 μg/ml), showed a remarkable decrease in its MIC (87% Pantibiotics. However, when used in combination with antibiotics, they showed remarkable synergistic effect and thus can help in prolonging the viability of these antibiotics against S. aureus infections. Furthermore, reduction in MIC of cefradine with oleanolic acid indicates their potential use against MRSA.

Quality control of direct molecular diagnostics for methicillin-resistant Staphylococcus aureus

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van Belkum, Alex; Niesters, Hubert G M; MacKay, William G; van Leeuwen, Willem B

Ten samples containing various amounts of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus, methicillin-resistant Staphylococcus epidermidis (MRSE), and combinations thereof were distributed to 51 laboratories for molecular diagnostics testing. Samples containing

Treatment of methicillin-resistant Staphylococcus aureus in Latin America Tratamento de Staphylococcus aureus resistente à meticilina na América Latina

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Carlos M Luna

2010-12-01

Full Text Available The global spread of methicillin-resistant Staphylococcus aureus (MRSA means it is now a pathogen of worldwide public health concern. Within Latin America, MRSA is highly prevalent, with the proportion of S. aureus isolates that are methicillin-resistant on the rise, yet resources for managing the infection are limited. While several guidelines exist for the treatment of MRSA infections, many are written for the North American or European setting and need adaptation for use in Latin America. In this article, we aim to emphasize the importance of appropriate treatment of MRSA in the healthcare and community settings of Latin America. We present a summary of the available guidelines and antibiotics, and discuss particular considerations for clinicians treating MRSA in Latin AmericaA propagação global de Staphylococcus aureus resistente à meticilina (methicillin-resistant Staphylococcus aureus - MRSA significa que se trata agora de um patógeno de interesse para a saúde pública mundial. Na América Latina, o MRSA é altamente prevalente, com a proporção de S. aureus resistente à meticilina em ascensão, no entanto os recursos para o tratamento da infecção são limitados. Embora existam várias diretrizes para o tratamento de infecções por MRSA, muitas são elaboradas para a América do Norte ou a Europa e precisam ser adaptadas para sua utilização na América Latina. Neste artigo, procuramos destacar a importância do tratamento adequado do MRSA nas unidades de saúde e na comunidade na América Latina. Apresentamos um resumo das diretrizes e dos antibióticos disponíveis, e discutimos considerações específicas para os médicos que tratam de MRSA na América Latina.

Methicillin Resistant Staphylococcus aureus Transmission in a Ghanaian Burn Unit: The Importance of Active Surveillance in Resource-Limited Settings

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Nana Ama Amissah

2017-10-01

Full Text Available Objectives:Staphylococcus aureus infections in burn patients can lead to serious complications and death. The frequency of S. aureus infection is high in low- and middle-income countries presumably due to limited resources, misuse of antibiotics and poor infection control. The objective of the present study was to apply population genomics to precisely define, for the first time, the transmission of antibiotic resistant S. aureus in a resource-limited setting in sub-Saharan Africa.Methods:Staphylococcus aureus surveillance was performed amongst burn patients and healthcare workers during a 7-months survey within the burn unit of the Korle Bu Teaching Hospital in Ghana.Results: Sixty-six S. aureus isolates (59 colonizing and 7 clinical were obtained from 31 patients and 10 healthcare workers. Twenty-one of these isolates were ST250-IV methicillin-resistant S. aureus (MRSA. Notably, 25 (81% of the 31 patients carried or were infected with S. aureus within 24 h of admission. Genome comparisons revealed six distinct S. aureus clones circulating in the burn unit, and demonstrated multiple transmission events between patients and healthcare workers. Further, the collected S. aureus isolates exhibited a wide range of genotypic resistances to antibiotics, including trimethoprim (21%, aminoglycosides (33%, oxacillin (33%, chloramphenicol (50%, tetracycline (59% and fluoroquinolones (100%.Conclusion: Population genomics uncovered multiple transmission events of S. aureus, especially MRSA, within the investigated burn unit. Our findings highlight lapses in infection control and prevention, and underscore the great importance of active surveillance to protect burn victims against multi-drug resistant pathogens in resource-limited settings.

Methicillin Resistant Staphylococcus aureus Transmission in a Ghanaian Burn Unit: The Importance of Active Surveillance in Resource-Limited Settings.

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Amissah, Nana Ama; Buultjens, Andrew H; Ablordey, Anthony; van Dam, Lieke; Opoku-Ware, Ampomah; Baines, Sarah L; Bulach, Dieter; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alexander W; Seemann, Torsten; van Dijl, Jan Maarten; Stienstra, Ymkje; Stinear, Timothy P; Rossen, John W

2017-01-01

Objectives: Staphylococcus aureus infections in burn patients can lead to serious complications and death. The frequency of S. aureus infection is high in low- and middle-income countries presumably due to limited resources, misuse of antibiotics and poor infection control. The objective of the present study was to apply population genomics to precisely define, for the first time, the transmission of antibiotic resistant S. aureus in a resource-limited setting in sub-Saharan Africa. Methods: Staphylococcus aureus surveillance was performed amongst burn patients and healthcare workers during a 7-months survey within the burn unit of the Korle Bu Teaching Hospital in Ghana. Results: Sixty-six S. aureus isolates (59 colonizing and 7 clinical) were obtained from 31 patients and 10 healthcare workers. Twenty-one of these isolates were ST250-IV methicillin-resistant S. aureus (MRSA). Notably, 25 (81%) of the 31 patients carried or were infected with S. aureus within 24 h of admission. Genome comparisons revealed six distinct S. aureus clones circulating in the burn unit, and demonstrated multiple transmission events between patients and healthcare workers. Further, the collected S. aureus isolates exhibited a wide range of genotypic resistances to antibiotics, including trimethoprim (21%), aminoglycosides (33%), oxacillin (33%), chloramphenicol (50%), tetracycline (59%) and fluoroquinolones (100%). Conclusion: Population genomics uncovered multiple transmission events of S. aureus , especially MRSA, within the investigated burn unit. Our findings highlight lapses in infection control and prevention, and underscore the great importance of active surveillance to protect burn victims against multi-drug resistant pathogens in resource-limited settings.

Diverse modulation of spa transcription by cell wall active antibiotics in Staphylococcus aureus

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Nielsen, Lene Nørby; Roggenbuck, Michael; Haaber, Jakob Krause

2012-01-01

ABSTRACT: BACKGROUND: The aim of this study was to investigate the effect of various classes of clinically relevant antibiotics at sub-lethal concentrations on virulence gene expression and biofilm formation in Staphylococcus aureus. FINDINGS: LacZ promoter fusions of genes related to staphylococ......ABSTRACT: BACKGROUND: The aim of this study was to investigate the effect of various classes of clinically relevant antibiotics at sub-lethal concentrations on virulence gene expression and biofilm formation in Staphylococcus aureus. FINDINGS: LacZ promoter fusions of genes related...... to staphylococcal virulence were used to monitor the effects of antibiotics on gene expression in a disc diffusion assay. The selected genes were hla and spa encoding alpha-hemolysin and Protein A, respectively and RNAIII, the effector molecule of the agr quorum sensing system. The results were confirmed...... by quantitative real-time PCR. Additionally, we monitored the effect of subinhibitory concentrations of antibiotics on the ability of S. aureus to form biofilm in a microtiter plate assay. The results show that sub-lethal antibiotic concentrations diversely modulate expression of RNAIII, hla and spa. Consistently...

Significant Differences Characterise the Correlation Coefficients between Biocide and Antibiotic Susceptibility Profiles in Staphylococcus aureus.

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Oggioni, Marco R; Coelho, Joana Rosado; Furi, Leonardo; Knight, Daniel R; Viti, Carlo; Orefici, Graziella; Martinez, Jose-Luis; Freitas, Ana Teresa; Coque, Teresa M; Morrissey, Ian

2015-01-01

There is a growing concern by regulatory authorities for the selection of antibiotic resistance caused by the use of biocidal products. We aimed to complete the detailed information on large surveys by investigating the relationship between biocide and antibiotic susceptibility profiles of a large number of Staphylococcus aureus isolates using four biocides and antibiotics commonly used in clinical practice. The minimal inhibitory concentration (MIC) for most clinically-relevant antibiotics was determined according to the standardized methodology for over 1600 clinical S. aureus isolates and compared to susceptibility profiles of benzalkonium chloride, chlorhexidine, triclosan, and sodium hypochlorite. The relationship between antibiotic and biocide susceptibility profiles was evaluated using non-linear correlations. The main outcome evidenced was an absence of any strong or moderate statistically significant correlation when susceptibilities of either triclosan or sodium hypochlorite were compared for any of the tested antibiotics. On the other hand, correlation coefficients for MICs of benzalkonium chloride and chlorhexidine were calculated above 0.4 for susceptibility to quinolones, beta-lactams, and also macrolides. Our data do not support any selective pressure for association between biocides and antibiotics resistance and furthermore do not allow for a defined risk evaluation for some of the compounds. Importantly, our data clearly indicate that there does not involve any risk of selection for antibiotic resistance for the compounds triclosan and sodium hypochlorite. These data hence infer that biocide selection for antibiotic resistance has had so far a less significant impact than feared.

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging pathogen in orthopaedics.

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Marcotte, Anthony L; Trzeciak, Marc A

2008-02-01

Staphylococcus aureus (S aureus) remains one of the most common pathogens for skin and soft-tissue infections encountered by the orthopaedic surgeon. Community-acquired methicillin-resistant S aureus (CA-MRSA) has become increasingly prevalent, particularly among athletes, children in day care, homeless persons, intravenous drug users, men who have sex with men, military recruits, certain minorities (ie, Alaskan Natives, Native Americans, Pacific Islanders), and prison inmates. Risk factors include antibiotic use within the preceding year, crowded living conditions, compromised skin integrity, contaminated surfaces, frequent skin-to-skin contact, shared items, and suboptimal cleanliness. When a patient presents with a skin or soft-tissue infection, the clinician should determine whether an abscess or other infection needs to be surgically incised and drained. Cultures should be performed. When the patient is a member of an at-risk group or has any of the risk factors for CA-MRSA, beta-lactam antibiotics (eg, methicillin) are no longer a reasonable choice for treatment. Empiric treatment should consist of non-beta-lactam antibiotics active against CA-MRSA.

Prevalence of methicillin resistant Staphylococcus aureus in Lumbini Medical College and Teaching Hospital, Palpa, Western Nepal.

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Raut, Shristi; Bajracharya, Kishor; Adhikari, Janak; Pant, Sushama Suresh; Adhikari, Bipin

2017-06-02

Multidrug resistant Staphylococcus aureus is common in both tertiary and primary health care settings. Emergence of methicillin resistance in S. aureus (MRSA) along with macrolide, lincosamide, streptogramin B (MLSB) has made treatment of Staphylococcal infection more challenging. The main objective of this study was to detect MRSA, MLSB (inducible; MLSBi and constitutive; MLSBc) resistant S. aureus using phenotypic methods and to determine their antibiogram. Various samples were collected from 1981 patients who attended Lumbini Medical College and Teaching Hospital (LMCTH) during the period of 6 months from September 2015 to February 2016. Out of a total of 1981 samples, 133 S. aureus were isolated. Cefoxitin was used to detect MRSA by the disk diffusion test. Inducible clindamycin resistance (MLSBi) was detected by the D-zone test. The antibiotic profile of all isolates was tested by a modified Kirby Bauer disk diffusion method. Among 133 S. aureus, there were 58 (43.6%) MRSA, 34 (25.6%) MLSBi and 30 (22.6%) MLSBc. Of a total of 64 MLSB, a significant proportion (62.5%) was MRSA (p aureus, MRSA showed significant resistance to 9 (p resistance to multiple antibiotics (p resistance profiles from this study can optimize the treatment of multi-drug resistant S. aureus.

Staphylococcus-Candida interaction models: antibiotic resistance testing and host interactions

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Scheres, C.R.; Krom, B.P.; Calderone, R.; Cihlar, R.

2016-01-01

The fungus Candida albicans and bacterium Staphylococcus aureus can coexist in polymicrobial biofilms. S. aureus attaches strongly to hyphae, but not to the yeast form, of C. albicans with important consequences for virulence. Hyphae-associated S. aureus is less susceptible to antibiotic treatment.

Clinical Outcome with Oral Linezolid and Rifampin Following Recurrent Methicillin-Resistant Staphylococcus aureus Bacteremia Despite Prolonged Vancomycin Treatment

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Jon-David Schwalm

2004-01-01

Full Text Available Drug-resistant Gram-positive bacteria, especially Staphylococcus aureus, are emerging as the predominant organisms involved in both nosocomial and community-acquired infections. Since the 1980s, vancomycin has been the first-line antibiotic used to treat methicillin-resistant S aureus. However, allergy and intolerance to vancomycin, the increasing number of vancomycin clinical failures and the existence of vancomycin intermediate-susceptible isolates of S aureus suggest that new antibiotics are needed. This paper reports the only known case of a successful clinical outcome with long term oral linezolid and rifampin therapy in the management of recurrent and persistent methicillin-resistant S aureus bacteremia with metastatic infections despite prolonged vancomycin use. More than two years since the initiation of linezolid and rifampin, the study patient has been clinically well with no evidence of adverse drug reactions including cytopenia and hepatic toxicities. Physicians must be aware of the novel developments in antibiotic therapy to treat drug-resistant bacterial infections.

PCR-based Approaches for the Detection of Clinical Methicillin-resistant Staphylococcus aureus

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Liu, Ying; Zhang, Jiang; Ji, Yinduo

2016-01-01

Staphylococcus aureus is an important pathogen that can cause a variety of infections, including superficial and systematic infections, in humans and animals. The persistent emergence of multidrug resistant S. aureus, particularly methicillin-resistant S. aureus, has caused dramatically economic burden and concerns in the public health due to limited options of treatment of MRSA infections. In order to make a correct choice of treatment for physicians and understand the prevalence of MRSA, it is extremely critical to precisely and timely diagnose the pathogen that induces a specific infection of patients and to reveal the antibiotic resistant profile of the pathogen. In this review, we outlined different PCR-based approaches that have been successfully utilized for the rapid detection of S. aureus, including MRSA and MSSA, directly from various clinical specimens. The sensitivity and specificity of detections were pointed out. Both advantages and disadvantages of listed approaches were discussed. Importantly, an alternative approach is necessary to further confirm the detection results from the molecular diagnostic assays. PMID:27335617

[Molecular characterization of resistance mechanisms: methicillin resistance Staphylococcus aureus, extended spectrum β-lactamases and carbapenemases].

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Oteo, Jesús; Belén Aracil, María

2015-07-01

Multi-drug resistance in bacterial pathogens increases morbidity and mortality in infected patients and it is a threat to public health concern by their high capacity to spread. For both reasons, the rapid detection of multi-drug resistant bacteria is critical. Standard microbiological procedures require 48-72 h to provide the antimicrobial susceptibility results, thus there is emerging interest in the development of rapid detection techniques. In recent years, the use of selective and differential culture-based methods has widely spread. However, the capacity for detecting antibiotic resistance genes and their low turnaround times has made molecular methods a reference for diagnosis of multidrug resistance. This review focusses on the molecular methods for detecting some mechanisms of antibiotic resistance with a high clinical and epidemiological impact: a) Enzymatic resistance to broad spectrum β-lactam antibiotics in Enterobacteriaceae, mainly extended spectrum β-lactamases (ESBL) and carbapenemases; and b) methicillin resistance in Staphylococcus aureus. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: A multicentre study.

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Rajaduraipandi K

2006-01-01

Full Text Available Purpose: Methicillin resistant Staphylococcus aureus (MRSA is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu. Methods: A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates. Results: Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1% and 39 (37.9% were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6% were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100% of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin. Conclusion: The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

Characterization of staphylococci in urban wastewater treatment plants in Spain, with detection of methicillin resistant Staphylococcus aureus ST398.

Science.gov (United States)

Gómez, Paula; Lozano, Carmen; Benito, Daniel; Estepa, Vanesa; Tenorio, Carmen; Zarazaga, Myriam; Torres, Carmen

2016-05-01

The objective of this study was to determine the prevalence of Staphylococcus in urban wastewater treatment plants (UWTP) of La Rioja (Spain), and to characterize de obtained isolates. 16 wastewater samples (8 influent, 8 effluent) of six UWTPs were seeded on mannitol-salt-agar and oxacillin-resistance-screening-agar-base for staphylococci and methicillin-resistant Staphylococcus aureus recovery. Antimicrobial susceptibility profile was determined for 16 antibiotics and the presence of 35 antimicrobial resistance genes and 14 virulence genes by PCR. S. aureus was typed by spa, agr, and multilocus-sequence-typing, and the presence of immune-evasion-genes cluster was analyzed. Staphylococcus spp. were detected in 13 of 16 tested wastewater samples (81%), although the number of CFU/mL decreased after treatment. 40 staphylococci were recovered (1-5/sample), and 8 of them were identified as S. aureus being typed as (number of strains): spa-t011/agr-II/ST398 (1), spa-t002/agr-II/ST5 (2), spa-t3262/agr-II/ST5 (1), spa-t605/agr-II/ST126 (3), and spa-t878/agr-III/ST2849 (1). S. aureus ST398 strain was methicillin-resistant and showed a multidrug resistance phenotype. Virulence genes tst, etd, sea, sec, seg, sei, sem, sen, seo, and seu, were detected among S. aureus and only ST5 strains showed genes of immune evasion cluster. Thirty-two coagulase-negative Staphylococcus of 12 different species were recovered (number of strains): Staphylococcus equorum (7), Staphylococcus vitulinus (4), Staphylococcus lentus (4), Staphylococcus sciuri (4), Staphylococcus fleurettii (2), Staphylococcus haemolyticus (2), Staphylococcus hominis (2), Staphylococcus saprophyticus (2), Staphylococcus succinus (2), Staphylococcus capitis (1), Staphylococcus cohnii (1), and Staphylococcus epidermidis (1). Five presented a multidrug resistance phenotype. The following resistance and virulence genes were found: mecA, lnu(A), vga(A), tet(K), erm(C), msr(A)/(B), mph(C), tst, and sem. We found that

Antimicrobial drug resistance in Staphylococcus aureus isolated from cattle in Brazil.

Science.gov (United States)

Pereira, M S; Siqueira-Júnior, J P

1995-06-01

Isolates of Staphylococcus aureus obtained from apparently healthy cattle in the State of Paraiba, Brazil were characterized in relation to resistance to 21 antimicrobial agents. Among the 46 isolates obtained, resistance to penicillin was most frequent, followed by resistance to cadmium, streptomycin, arsenate, tetracycline, mercury, erythromycin and kanamycin/neomycin. All isolates were susceptible to fusidic acid, ethidium bromide, cetrimide, chloramphenicol, benzalkonium chloride, doxycycline, gentamicin, methicillin, minocycline, novobiocin, rifamycin, tylosin and vancomycin. Only six isolates were susceptible to all the drugs tested. With respect to the antibiotics, multi-resistant isolates were uncommon. These results are probably a consequence of the peculiarities of local drug usage pressures. In relation to metal ions, resistance to mercury was rare while resistance to arsenate was relatively frequent, which contrasts with the situation for human Staph. aureus strains. After treatment with ethidium bromide, elimination of resistance to penicillin, tetracycline, streptomycin, erythromycin and cadmium was observed, which was consistent with the genetic determinants being plasmid-borne.

Concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Science.gov (United States)

Wang, Li Jun; Du, Xiao Qin; Nyirimigabo, Eric; Shou, Song Tao

2014-04-01

It is rare to see a concurrent infection with infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus in Tianjin, China. Until now, there is still no any single recorded case of concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Characterisation of SCCmec elements in methicillin-resistant Staphylococcus aureus isolated from burn patients.

Science.gov (United States)

Namvar, Amirmorteza Ebrahimzadeh; Afshar, Mastaneh; Asghari, Babak; Rastegar Lari, Abdolaziz

2014-06-01

Staphylococcus aureus is an important pathogen, especially in burn units all around the world. Because of the emergence of the β-lactam antibiotic-resistant strains since 1961, concern about the prevalence of methicillin-resistant S. aureus (MRSA) has increased in these units. Resistance to methicillin is mediated by penicillin-binding proteins (PBPs) that have enough affinity for binding to the β-lactam ring, but another kind of protein (PBP2α), which is encoded by the mecA gene, has a lower affinity for binding to these antibiotics. The mecA gene is transferred by SCCmec (staphylococcal cassette chromosome mec) as a mobile genetic element, exclusively found in the Staphylococcus genus. Identification of the frequency of the mecA gene, different SCCmec types and also its incidence may have benefit in surveillance prevention and control of MRSA strains in burn units. In this study, 40 S. aureus isolates were collected from patients hospitalised in Motahari burn center of Tehran, during 2012-2013. Conventional microbiological methods were applied and the confirmed isolates were stored at -20°C for molecular polymerase chain reaction (PCR) tests. The antibiotic resistance pattern was performed by disc diffusion method and finally the different SCCmec types were determined by specific primers. During this research, 40 isolates of S. aureus were collected from burn patients, of which (37.5%) of the specimens belonged to female patients and 62.5% to male patients. The aetiology of the burn was classified as follows: open flame (35%), liquid (32.5%), chemical (5%) and other (27.5%). By a disc diffusion method, no resistance pattern was observed to vancomycin and fosfomycin. Based on a multiplex PCR assay, the five different SCCmec types were detected as: 47.5% type III, 25% type IV, 10% type V, 10% type II and 7.5% type I. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

Antibiotic Resistance Profile for Staphylococcus Species Recovered from Milk

International Nuclear Information System (INIS)

Gad EL-Rab, S.F.; Osman, K.M.; Kamel, M.A.

2017-01-01

A total of 220 milk samples from buffaloes and cows (150 from buffaloes and 70 from cows) were investigated. Samples were cultured on Baird Parker media for isolation of Staphylococcus, especially S.aureus from apparently normal, clinical and subclinical mastitis cases. The total isolates were 42(19%) from raw milk samples (27 from buffaloes and 15 from cows) 220. The aim of this study is to characterize phenotypically Staphylococcus spp. The collected samples were taken from selected are as to increase the range of information available about antibiotic resistance profile. This enhances formulating strategies to reduce the spread of this bacterium and also avoiding its health hazard on animals and human beings

Structural characterization of Staphylococcus aureus biotin protein ligase and interaction partners: An antibiotic target

OpenAIRE

Pendini, Nicole R; Yap, Min Y; Polyak, Steven W; Cowieson, Nathan P; Abell, Andrew; Booker, Grant W; Wallace, John C; Wilce, Jacqueline A; Wilce, Matthew C J

2013-01-01

The essential metabolic enzyme biotin protein ligase (BPL) is a potential target for the development of new antibiotics required to combat drug-resistant pathogens. Staphylococcus aureus BPL (SaBPL) is a bifunctional protein, possessing both biotin ligase and transcription repressor activities. This positions BPL as a key regulator of several important metabolic pathways. Here, we report the structural analysis of both holo- and apo-forms of SaBPL using X-ray crystallography. We also present ...

Screening of nasal carriage of methicillin-resistant Staphylococcus aureus during admission of patients to Frantz Fanon Hospital, Blida, Algeria

Directory of Open Access Journals (Sweden)

Mohamed Amine Ouidri

2018-05-01

Full Text Available A study was performed of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA strains isolated from nasal preoperative samples. Of 663 samples assessed, staphylococcus was detected in 143 (21.57%. The disc diffusion method (cefoxitin 30 μg, a screening test (oxacillin 6 μg/mL and a search for Protein Binding Additional Penicillin 2 (PLP2a allowed the detection and confirmation of resistance to methicillin for 36 strains, a rate of 5.43% of the total population studied. Eight MRSA carriers received care in the trauma service, 14 in cardiology, five in ear, nose and throat, four in neurosurgery and paediatrics, and one in SCI. Thirty-six methicillin-resistant of the nasal portage strains are in their great majority, 27 of 36, rather limited multi-R character (two to three families namely resistance: tetracyclines, fluoroquinolones, aminoglycosides, macrolides. One of the MRSA strains was found to have intermediate sensitivity to vancomycin. Keywords: Antibiotic resistance, Healthy volunteers, MRSA, Prevalence, Staphylococcus aureus

The Lytic SA Phage Demonstrate Bactericidal Activity against Mastitis Causing Staphylococcus aureus

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Hamza Ameer

2016-01-01

Full Text Available Staphylococcus aureus is the major causative agent of mastitis among dairy animals as it causes intramammary gland infection. Due to antibiotic resistance and contamination of antibiotics in the milk of diseased animals; alternative therapeutic agents are required to cure mastitis. Lytic bacteriophages and their gene products can be potential therapeutic agents against bacteria as they are host specific and less harmful than antibiotics. In this study, Staphylococcus aureus were isolated from milk samples of the infected animals and identified biochemically. SA phage was isolated from sewage water showing lytic activity against Staphylococcus aureus isolates. The highest lytic activity of bacteriophages was observed at 37°C and pH 7, and the most suitable storage condition was at 4°C. SA phage efficiently reduced bacterial growth in the bacterial reduction assay. The characterization and bacterial growth reduction activity of the bacteriophages against Staphylococcus aureus signifies their underlying potential of phage therapy against mastitis.

Prevalence of methicillin-resistant Staphylococcus aureus and ...

African Journals Online (AJOL)

Wound colonization by microorganisms is most frequently polymicrobial and incidences of high level resistance among bacterial isolates from wounds have been reported. Methicillin-resistant Staphylococcus aureus (MRSA) and extendedspectrum beta-lactamase (ESBL) producing Gram-negative bacteria both constitute ...

Primary care treatment guidelines for skin infections in Europe: congruence with antimicrobial resistance found in commensal Staphylococcus aureus in the community

NARCIS (Netherlands)

van Bijnen, E.M.E.; Paget, W.J.; den Heijer, C.D.J.; Stobberingh, E.E.; Bruggeman, C.A.; Schellevis, F.G.

2014-01-01

Background: Over 90% of antibiotics for human use in Europe are prescribed in primary care. We assessed the congruence between primary care treatment guidelines for skin infections and commensal Staphylococcus aureus (S. aureus) antimicrobial resistance levels in community-dwelling persons. Methods:

Primary care treatment guidelines for skin infections in Europe: congruence with antimicrobial resistance found in commensal Staphylococcus aureus in the community.

NARCIS (Netherlands)

Bijnen, E.M.E. van; Paget, W.J.; Heijer, C.D.J. den; Stobberingh, E.E.; Bruggeman, C.A.; Schellevis, F.G.

2014-01-01

Background: Over 90% of antibiotics for human use in Europe are prescribed in primary care. We assessed the congruence between primary care treatment guidelines for skin infections and commensal Staphylococcus aureus (S. aureus) antimicrobial resistance levels in community-dwelling persons. Methods:

Detection of Antibiotic Resistant Staphylococcus aureus from Milk: A Public Health Implication

Science.gov (United States)

Akindolire, Muyiwa Ajoke; Babalola, Olubukola Oluranti; Ateba, Collins Njie

2015-01-01

The aim of this study was to investigate the occurrence, antibiotic susceptibility profiles, and virulence genes determinants of S. aureus isolated from milk obtained from retail outlets of the North-West Province, South Africa. To achieve this, 200 samples of raw, bulk and pasteurised milk were obtained randomly from supermarkets, shops and some farms in the North-West Province between May 2012 and April 2013. S. aureus was isolated and positively identified using morphological (Gram staining), biochemical (DNase, catalase, haemolysis and rapid slide agglutination) tests, protein profile analysis (MALDI-TOF mass spectrometry) and molecular (nuc specific PCR) methods. The antimicrobial resistance profiles of the isolates were determined using the phenotypic agar diffusion method. Genes encoding enterotoxins, exfoliative toxins and collagen adhesins were also screened using PCR. Among all the samples examined, 30 of 40 raw milk samples (75%), 25 of 85 bulk milk samples (29%) and 10 of 75 pasteurised milk samples (13%) were positive for S. aureus. One hundred and fifty-six PCR-confirmed S. aureus isolates were obtained from 75 contaminated milk samples. A large proportion (60%–100%) of the isolates was resistant to penicillin G, ampicillin, oxacillin, vancomycin, teicoplanin and erythromycin. On the contrary, low level resistance (8.3%–40%) was observed for gentamicin, kanamycin and sulphamethoxazole. Methicillin resistance was detected in 59% of the multidrug resistant isolates and this was a cause for concern. However, only a small proportion (20.6%) of these isolates possessed PBP2a which codes for Methicillin resistance in S. aureus. In addition, 32.7% of isolates possessed the sec gene whereas the sea, seb sed, see, cna, eta, etb genes were not detected. The findings of this study showed that raw, bulk and pasteurised milk in the North-West Province is contaminated with toxigenic and multi-drug resistant S. aureus strains. There is a need to implement

Isolation of methicillin-resistant Staphylococcus aureus from small ruminants and their meat at slaughter and retail level in Greece.

Science.gov (United States)

Sergelidis, D; Papadopoulos, T; Komodromos, D; Sergelidou, E; Lazou, T; Papagianni, M; Zdragas, A; Papa, A

2015-11-01

Methicillin-resistant Staphylococcus aureus (MRSA) presents major health risk for humans causing serious nosocomial and community-acquired infections. Asymptomatic food-producing animal carriers and their meat may represent potential reservoirs for human infections. The aim of this study was to investigate the prevalence of MRSA in small ruminants raised under free-range conditions and their meat at slaughter and retail level in Northern Greece. Staphylococcus aureus was isolated from 9·6% of the examined samples. All isolates were resistant at least to one antibiotic, whereas 59·3% of them were multidrug resistant (MDR) exhibiting resistance to three or more antibiotic classes. The higher resistance rates were observed against penicillin (100%), tetracycline (74%), clindamycin (59·3%) and erythromycin (51·9%). Resistance to cefoxitin was exhibited by 22·2% of the isolates, but only one isolate was found to carry the mecA gene and belonged to spa type t127. This is the first time this type of Staph. aureus is isolated in Greece from the surface of a small ruminant's carcass. The presence of multidrug resistant Staph. aureus, and especially MRSA, in small ruminants and their meat, represents a potential threat for the spread of this pathogen in the community. This study is the first report on methicillin-resistant Staphylococcus aureus in small ruminants and their meat at slaughter level in Greece, elucidating a possible vehicle food for transmission to humans. These results suggest that human or animal sources could be involved in meat contamination and thus sources of contamination require investigation to control the dispersion of MRSA in the community. © 2015 The Society for Applied Microbiology.

Linezolid and Tiamulin Cross-Resistance in Staphylococcus aureus Mediated by Point Mutations in the Peptidyl Transferase Center ▿

OpenAIRE

Miller, Keith; Dunsmore, Colin J.; Fishwick, Colin W. G.; Chopra, Ian

2008-01-01

Oxazolidinone and pleuromutilin antibiotics are currently used in the treatment of staphylococcal infections. Although both antibiotics inhibit protein synthesis and have overlapping binding regions on 23S rRNA, the potential for cross-resistance between the two classes through target site mutations has not been thoroughly examined. Mutants of Staphylococcus aureus resistant to linezolid were selected and found to exhibit cross-resistance to tiamulin, a member of the pleuromutilin class of an...

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

Science.gov (United States)

Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

2015-06-01

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk

Science.gov (United States)

Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A.; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

2015-01-01

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene. PMID:26273271

In silico analysis for identifying potential vaccine candidates against Staphylococcus aureus

OpenAIRE

Delfani, Somayeh; Imani Fooladi, Abbas Ali; Mobarez, Ashraf Mohabati; Emaneini, Mohammad; Amani, Jafar; Sedighian, Hamid

2015-01-01

Purpose Staphylococcus aureus is one of the most important causes of nosocomial and community-acquired infections. The increasing incidence of multiple antibiotic-resistant S. aureus strains and the emergence of vancomycin resistant S. aureus strains have placed renewed interest on alternative means of prevention and control of infection. S. aureus produces a variety of virulence factors, so a multi-subunit vaccine will be more successful for preventing S. aureus infections than a mono-subuni...

Methicillin-resistant Staphylococcus aureus isolates from Iranian ...

African Journals Online (AJOL)

Methicillin-resistant Staphylococcus aureus isolates from Iranian restaurant food samples: Panton-Valentine Leukocidin, SCCmec phenotypes and antimicrobial resistance. ... TetK (80.72 %), linA (67.46 %), aadA1 (62.65 %), and msrA (55.42 %) were the most frequently identified resistance genes. SCCmec V (57.83%) ...

Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus

Science.gov (United States)

Vandecandelaere, Ilse; Van Nieuwerburgh, Filip; Deforce, Dieter

2017-01-01

In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other’s behavior, but additional studies are required necessary to elucidate the exact

Characterization of methicillin-resistant Staphylococcus aureus Sequence Type 398

DEFF Research Database (Denmark)

Christiansen, Mette Theilgaard

Staphylococcus aureus is an opportunistic pathogen that colonizes the nares and skin surfaces of several animal species, including man. S. aureus can cause a wide variety of infections ranging from superficial soft tissue and skin infections to severe and deadly systemic infections. Traditionally S....... aureus and methicillin-resistant Staphylococcus aureus (MRSA) have been associated with hospitals, but during the past decades MRSA has emerged in the community and now a new branch of MRSA has been found in association with livestock (LA-MRSA). A specific lineage (multilocus sequence type 398 (ST398...

Comparison of in vitro efficacy of linezolid and vancomycin by determining their minimum inhibitory concentrations against methicillin resistant Staphylococcus aureus (MRSA)

International Nuclear Information System (INIS)

Kaleem, F.; Usman, J.; Hassan, A.

2011-01-01

Objectives: To compare the in vitro activities of vancomycin and linezolid against methicillin resistant Staphyloccus aureus in our set up to help in formulating a better empirical treatment and reduce the emergence of vancomycin resistant Staphylococcus aureus. Methods: The study was conducted over a period of 6 months(July 1, 2009 - Dec 1, 2009). Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military Hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. Results: All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. Conclusion: This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphyloccus aureus infections. (author)

Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus

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Sang Mi Han

2016-01-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA, along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV, alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC, minimum bactericidal concentrations (MBC and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

[Sepsis with Staphylococcus aureus in immunocompromised patients].

Science.gov (United States)

Petrache, Simona Magdalena; Miftode, Egidia; Vâţă, A; Petrovici, Cristina Mirela; Dorneanu, Olivia; Luca, V

2009-01-01

The aim of our study was to analyze clinical and biological characteristics of immunocompromised patients with staphylococcal sepsis and to compare with the same data in non-immunocompromised patients. The diagnosis of sepsis was made based on Bone criteria. MiniAPI system ID 32 STAPH was used for identification and antibiotic susceptibility was assessed by ATB STAPH method and by E-test for oxacillin and vancomycin. Among the 147 patients with Staphylococcus aureus sepsis--66.67% had concomitant immunosuppressive conditions (diabetes mellitus, liver diseases, renal failure, corticotherapy, etc). We have found a significant correlation between the immunosuppressed status and MRSA (methicillin-resistant Staphylococcus aureus) involvement (p = 0.0018) and also, between this group of patients and treatment failure (p = 0.0012). Because of the high rate of MRSA involvement in systemic infections in the Eastern region of Romania first intention treatment of patients with staphylococcal infections and conditions of immunosuppression must include antibiotics effective against methicillin-resistant strains.

Pediatric neck abscesses: No increase in methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Fellner, Avital; Marom, Tal; Muallem-Kalmovich, Limor; Shlamkovitch, Nathan; Eviatar, Ephraim; Lazarovitch, Tzilia; Pitaro, Jacob

2017-10-01

Recent studies from Western countries showed an increased incidence rate of methicillin-resistant Staphylococcus aureus (MRSA) isolated from pediatric neck abscesses cultures. We sought to examine the microbiology and antibiotic susceptibility of such samples over a 10-year period, and particularly of Staphylococcus aureus (SA), in order to determine whether a similar trend exists in our institution. A retrospective chart review of children ≤18 years that underwent needle aspiration or surgical drainage of neck abscesses, including suppurative lymphadenitis, retropharyngeal abscesses, and parapharyngeal abscesses was conducted between 1/1/06-31/12/15. Sixty-two children were identified with a male predominance (34, 55%). The median age was 2 years. There were 37 (60%) suppurative lymphadenitis, 15 (24%) parapharyngeal abscess, and 10 (16%) retropharyngeal abscess cases. Twenty-nine (47%) children received antibiotic treatment prior to admission, most commonly β-lactam agents. Of them, 15 (52%) had positive cultures, including 7 (47%) with SA. On admission, 45 (73%) children had already received amoxicillin-clavulanate. Of those who did not improve, 16 (26%) received ceftriaxone and clindamycin. Twenty-one (38%) cultures were negative. The most common isolated bacteria were SA in 13 (24%), Streptococcus pyogenes in 7 (13%), and Streptococcus viridians group in 9 (16%). Of the SA isolates, there was only 1 (8%) case of MRSA; however, there were 4 (31%) clindamycin-resistant SA isolates. Unlike previously published data, there was no increase in MRSA incidence at our institution. However, the high prevalence of clindamycin-resistant SA was in line with previous reports. These findings should be considered when starting empirical therapy in pediatric neck abscesses. Copyright © 2017 Elsevier B.V. All rights reserved.

Antibiotic resistance

Directory of Open Access Journals (Sweden)

Marianne Frieri

2017-07-01

Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department

In vitro pharmacokinetics of antimicrobial cationic peptides alone and in combination with antibiotics against methicillin resistant Staphylococcus aureus biofilms.

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Dosler, Sibel; Mataraci, Emel

2013-11-01

Antibiotic therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections is becoming more difficult in hospitals and communities because of strong biofilm-forming properties and multidrug resistance. Biofilm-associated MRSA is not affected by therapeutically achievable concentrations of antibiotics. Therefore, we investigated the in vitro pharmacokinetic activities of antimicrobial cationic peptides (AMPs; indolicidin, cecropin [1-7]-melittin A [2-9] amide [CAMA], and nisin), either alone or in combination with antibiotics (daptomycin, linezolid, teicoplanin, ciprofloxacin, and azithromycin), against standard and 2 clinically obtained MRSA biofilms. The minimum inhibitory concentrations (MIC) and minimum biofilm-eradication concentrations (MBEC) were determined by microbroth dilution technique. The time-kill curve (TKC) method was used to determine the bactericidal activities of the AMPs alone and in combination with the antibiotics against standard and clinically obtained MRSA biofilms. The MIC values of the AMPs and antibiotics ranged between 2 to 16 and 0.25 to 512 mg/L, and their MBEC values were 640 and 512 to 5120 mg/L, respectively. The TKC studies demonstrated that synergistic interactions occurred most frequently when using nisin+daptomycin/ciprofloxacin, indolicidin+teicoplanin, and CAMA+ciprofloxacin combinations. No antagonism was observed with any combination. AMPs appear to be good candidates for the treatment of MRSA biofilms, as they act as both enhancers of anti-biofilm activities and help to prevent or delay the emergence of resistance when used either alone or in combination with antibiotics. Copyright © 2013 Elsevier Inc. All rights reserved.

Prevalence of Methicillin and Vancomycin resistant Staphylococcus aureus colonization in nasopharynx; Amir-Alam hospital, 2005

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Hasibi M

2007-07-01

Full Text Available Background: Staphylococcus aureus is one of the most common causes of nosocomial infections with high morbidity and mortality rate. Traditionally, methicillin resistant staphylococcus aureus has been considered a major nosocomial pathogen in healthcare facilities, but in the past decade, it has been observed emerging in the community as well. Informations regarding hospital microbial colonization could be an important step for prevention of nosocomial infections. Our objective was clarifying the prevalence of methicillin resistant and vancomycin resistant staphylococcus aureus colonization in nasopharynx. Methods: A descriptive cross sectional study was carried on 106 patients and nursing staff of surgery and hemodialysis wards in Amir-Alam hospital from April 2005 to July 2005. The samples were collected from nasal region of cases using cotton swab by two experienced technician and were sent to laboratory for culture and antibiogram. Results: Twenty six (29.5% out of 106 cases were nasopharyngeal carriers of staphylococcus aureus. Eight cases (7.5% had methicillin resistant staphylococcus aureus. The most frequent colonization rate was seen in hemodialysis nursing staff and in all of them methicillin resistant staphylococcus aureus was reported. Carrier rates in hemodialysis patients were twice compared to surgery ward patients. The interesting point was that no sample of vancomycin resistant staphylococcus aureus was isolated. Conclusion: Prevalence of methicillin resistant staphylococcus aureus colonization seems to be increased; therefore proper management for controlling this problem is mandatory. The results of the present study suggest that the prevalence of methicillin resistant staphylococcus aureus infections is higher than was expected in Iran and vigorous preventive strategies should therefore be taken to stop the growth of this major health problem.

Antibiotic sensitivity pattern of Staphylococcus aureus from clinical ...

African Journals Online (AJOL)

Background: The importance of Staphylococcus aureus as a persistent nosocomial and community acquired pathogen has become a global health concern. It has a remarkable capability of evolving different mechanisms of resistance to most antimicrobial agents. The aim of the present study is to establish the incidence of ...

Antimicrobial activity of zinc and titanium dioxide nanoparticles against biofilm-producing methicillin-resistant Staphylococcus aureus

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Jesline, A.; John, Neetu P.; Narayanan, P. M.; Vani, C.; Murugan, Sevanan

2015-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major nosocomial pathogens responsible for a wide spectrum of infections and the emergence of bacterial resistance to antibiotics has lead to treatment drawbacks towards large number of drugs. Formation of biofilms is the main contributing factor to antibiotic resistance. The development of reliable processes for the synthesis of zinc oxide nanoparticles is an important aspect of nanotechnology today. Zinc oxide and titanium dioxide nanoparticles comprise well-known inhibitory and bactericidal effects. Emergence of antimicrobial resistance by pathogenic bacteria is a major health problem in recent years. This study was designed to determine the efficacy of zinc and titanium dioxide nanoparticles against biofilm producing methicillin-resistant S. aureus. Biofilm production was detected by tissue culture plate method. Out of 30 MRSA isolates, 22 isolates showed strong biofilm production and 2 showed weak and moderate biofilm formation. Two strong and weak biofilm-producing methicillin-resistant S. aureus isolates were subjected to antimicrobial activity using commercially available zinc and titanium dioxide nanoparticles. Thus, the nanoparticles showed considerably good activity against the isolates, and it can be concluded that they may act as promising, antibacterial agents in the coming years.

Antibiotic-mediated selection of quorum-sensing-negative Staphylococcus aureus

DEFF Research Database (Denmark)

Paulander, Wilhelm Erik Axel; Varming, Anders Nissen; Bæk, Kristoffer Torbjørn

2012-01-01

of glycopeptide resistance greater than those of other strains. We show here that agr-negative strains have a fitness advantage over agr-positive strains in the presence of sublethal concentrations of some antibiotics and that the fitness defect of agr-positive cells is caused by antibiotic-mediated expression...... expression. We demonstrate that the presence of the agr locus imposes a fitness cost on S. aureus that is mediated by the expression of RNAIII. Further, we show that exposure to sublethal levels of the antibiotics ciprofloxacin, mupirocin, and rifampin, each targeting separate cellular functions, markedly...... increases the agr-mediated fitness cost by inducing the expression of RNAIII. Thus, the extensive use of antibiotics in hospitals may explain why agr-negative variants are frequently isolated from hospital-acquired S. aureus infections but rarely found among community-acquired S. aureus strains. Importantly...

Fitness and competitive growth comparison of methicillin resistant and methicillin susceptible Staphylococcus aureus colonies.

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Durhan, Emine; Korcan, Safiye Elif; Altindis, Mustafa; Konuk, Muhsin

2017-05-01

Exponential developments of both Methicillin resistant Staphylococcus aureus (MRSA) 3R ve 36R and methicillin susceptible Staphylococcus aureus (MSSA) 27S were evaluated in the presence and absence of oxacillin. The strains were isolated from the specimens collected in microbiology department. It was also determined the transfer of mecA gene from 3R to 27S strain by using the replica plate technique. It was observed that the presence of antibiotics in the preliminary culture had a positive impact on the growth of the secondary culture of MRSA isolates. Comparison results of Rt bacteria in three different mixed cultures, assessed with Tukey's HSD test, showed a significant statistical difference among the groups. The values were as following; on the first day; Df: 2, F: 60.90, P: 0.0001, second day; Df:2, F:90.56, P: 0.0000, and third day; Df:2, F:4.86, P:0.0557. As a result of the study, we can suggest that the gene expression levels of the transferred antibiotic resistance genes could help us in both controlling hospital originated sickness and developing new strategies to prevent the spread of resistant bacteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk

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Katheryne Benini Martins

2015-06-01

Full Text Available The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT, somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst, biofilm (icaA, icaC, icaD, bap, leukocidin (luk-PV oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics. Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

Novel quorum-quenching agents promote methicillin-resistant Staphylococcus aureus (MRSA) wound healing and sensitize MRSA to β-lactam antibiotics.

Science.gov (United States)

Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V; Viswanathan, Rajesh; Shoham, Menachem

2015-03-01

The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85-91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Controlling antibiotic resistance in the ICU

NARCIS (Netherlands)

Derde, L.P.G.

2013-01-01

Patients admitted to intensive care units (ICUs) are frequently colonized with (antibiotic-resistant) bacteria, which may lead to healthcare associated infections. Antimicrobial-resistant bacteria (AMRB), such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci

Evaluation of expression of NorA efflux pump in ciprofloxacin resistant Staphylococcus aureus against hexahydroquinoline derivative by real-time PCR.

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Pourmand, Mohammad Reza; Yousefi, Masoud; Salami, Seyed Alireza; Amini, Mohsen

2014-01-01

Staphylococcus aureus causes a wide variety of infections worldwide. Methicillin-resistant S. aureus is one of most common causes of nosocomial and community acquired infections. The fluoroquinolones are an important class of antibiotics that used to treat infections caused by S. aureus. Today, a significant increase in the rate of ciprofloxacin resistance in methicillin-resistant S. aureus strains is concerning. The norA efflux pump is considered as contributors to antibiotic resistance. Here, we aimed to evaluate the expression of norA efflux pump in the presence of hexahydroquinoline derivative in methicillin and ciprofloxacin resistant S. aureus. We were determined minimum inhibitory concentration of ciprofloxacin and hexahydroquinoline derivative and their combination by broth microdilution method against ciprofloxacin resistant S. aureus. The expression of the norA efflux pump gene was evaluated by quantitative Real-time PCR. This study showed that minimum inhibitory concentrations of ciprofloxacin in the presence of hexahydroquinoline derivative in comparison to ciprofloxacin were decreased. Quantitative Real-time PCR identified the increased expression of norA efflux pump gene in methicillin and ciprofloxacin resistant S. aureus strain. The increased expression of norA efflux pump gene may have resulted in the effort of S. aureus to survive. The results showed that the hexahydroquinoline derivative enhanced the antibacterial effect of ciprofloxacin against methicillin and ciprofloxacin resistant S. aureus. Therefore, the derivatives may be used as inhibitors of antibiotic resistance for combination therapy.

Antibiotic resistance in bacteria Staphylococcus spp. isolated from samples of raw sheep's milk

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Milan Vasiľ

2016-12-01

Full Text Available From samples of raw sheep's milk were determined results of bacteriological examination from two herds in region of Eastern Slovakia in three years lasting study. The occurrence of Staphylococcus spp. 41.6% (124 was determined from 298 samples. The seven species of staphylococci were on a regular basis isolated: S. epidermidis (34, S. chromogenes (26, S. aureus (16. Alternately have been recorded S. warneri (16, S. schleiferi (15, S. haemolyticus (9 and S. xylosus (8. All isolated pathogens were tested by in vitro test on Mueller-Hinton agar by disc methods on resistance to 10 types of antibiotics.  Highest value of resistance was determined to Penicilin 21.0%, Neomycin 10.5% and Novobiocin 9.7%. Lower resistance was in to Oxacilin 7.2% and Amoxicilin 6.5%. Minimal resistance was founded to Cefoxitin 0.8%, Linkomycin 2.4%, Erytromycin, and Streptomycin 3.2%. Was founded total resistance (21.0% to all antibiotics in S. epidermidis (34 during the three years, S. chromogenes (26 showed resistance to 8 types of antibiotics (12.9%, S. aureus (16 to 6 antibiotics (10.5% and S. warneri (16 to 4 antibiotics (5.6%. It was confirmed that sheep's milk remains a major source of staphylococci. Bacteria in comparison with isolates from cows' raw milk, showed lower values of resistance, but were resistant to more than two antibiotics. Recorded occurrence of resistance in staphylococci may be connected with a minimum use of antibiotics in the treatment of mastitis and other diseases in sheep herds. Reported resistance to the tested antibiotics became the basis for the recommendation to use preparations to treat mastitis in sheep principally by the detection of resistance to antibiotics contained.

Calcium and Magnesium Ions Are Membrane-Active against Stationary-Phase Staphylococcus aureus with High Specificity

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Xie, Yuntao; Yang, Lihua

2016-02-01

Staphylococcus aureus (S. aureus) is notorious for its ability to acquire antibiotic-resistance, and antibiotic-resistant S. aureus has become a wide-spread cause of high mortality rate. Novel antimicrobials capable of eradicating S. aureus cells including antibiotic-resistant ones are thus highly desired. Membrane-active bactericides and species-specific antimicrobials are two promising sources of novel anti-infective agents for fighting against bacterial antibiotic-resistance. We herein show that Ca2+ and Mg2+, two alkaline-earth-metal ions physiologically essential for diverse living organisms, both disrupt model S. aureus membranes and kill stationary-phase S. aureus cells, indicative of membrane-activity. In contrast to S. aureus, Escherichia coli and Bacillus subtilis exhibit unaffected survival after similar treatment with these two cations, indicative of species-specific activity against S. aureus. Moreover, neither Ca2+ nor Mg2+ lyses mouse red blood cells, indicative of hemo-compatibility. This works suggests that Ca2+ and Mg2+ may have implications in targeted eradication of S. aureus pathogen including the antibiotic-resistant ones.

Vancomycin Resistance in Staphylococcus aureus


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McGuinness, Will A.; Malachowa, Natalia; DeLeo, Frank R.

2017-01-01

The evolution of Staphylococcus aureus during the modern antibiotic era has been delineated by distinct strain emergence events, many of which include acquisition of antibiotic resistance. The relative high burden of methicillin-resistant S. aureus (MRSA) in healthcare and community settings is a major concern worldwide. Vancomycin, a glycopeptide antibiotic that inhibits cell wall biosynthesis, remains a drug of choice for treatment of severe MRSA infections. S. aureus strains exhibiting increased resistance to vancomycin, known as vancomycin intermediate-resistant S. aureus (VISA) (MIC = 4-8 µg/mL), were discovered in the 1990s. The molecular basis of resistance in VISA is polygenic and involves stepwise mutations in genes encoding molecules predominantly involved in cell envelope biosynthesis. S. aureus isolates with complete resistance to vancomycin (MIC ≥ 16 µg/mL) are termed vancomycin-resistant S. aureus (VRSA)—they were first reported in the U.S. in 2002. Resistance in VRSA is conferred by the vanA gene and operon, which is present on a plasmid. Although treatment of VRSA infections is challenging, the total number of human VRSA infections to date is limited (14 in the U.S.). By comparison, the burden of VISA is relatively high and the molecular mechanisms of resistance are less well-defined. VISA are associated with persistent infections, vancomycin treatment failure, and poor clinical outcomes. Here, we review in brief progress made toward understanding the acquisition of antibiotic resistance in S. aureus, with an emphasis on the molecular mechanisms underlying vancomycin resistance. PMID:28656013

Modulation of the norfloxacin resistance in Staphylococcus aureus by Cordia verbenaceae DC.

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Matias, Edinardo F F; Santos, Karla K A; Falcão-Silva, Vivyanne S; Siqueira-Junior, Jose P; Costa, Jose G M; Coutinho, Henrique D M

2013-01-01

Several chemical compounds isolated from natural sources have antibacterial activity and some enhance the antibacterial activity of antibiotics reversing the natural resistance of bacteria to certain antibiotics. In this study, the hexane and methanol extract of Cordia verbenaceae were assessed for antibacterial activity alone and combinated with norfloxacin against the Staphylococcus aureus strain SA1199B. The minimum inhibitory concentration (MIC) of extracts was assayed using microdilution assay and the modulatory activity was evaluated using plate diffusion assay. The MIC observed varied between 256 to >1024 μg/ml. However, the antibiotic activity of norfloxacin was enhanced in the presence of subinhibitory concentrations of hexane extract of C. verbenaceae (HECV). INTERPRETATIONS & CONCLUSIONS: Our results indicate that Cordia verbenaceae DC. can be a source of plant derived products with antibiotic modifying activity.

Inducible clindamycin and methicillin resistant Staphylococcus aureus in a tertiary care hospital, Kathmandu, Nepal.

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Adhikari, R P; Shrestha, S; Barakoti, A; Amatya, R

2017-07-11

Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin. This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS B resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test). Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycin-resistance: 79.4% Vs 41.8%). The overall prevalence of i MLS B and c MLS B phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both i MLS B and c MLS B phenotypes predominated in MRSA strains. Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of i MLS B and c MLS B especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.

Skin and soft tissue infections in intercontinental travellers and the import of multi-resistant Staphylococcus aureus to Europe

NARCIS (Netherlands)

Nurjadi, D.; Friedrich-Jänicke, B.; Schäfer, J.; van Genderen, P. J. J.; Goorhuis, A.; Perignon, A.; Neumayr, A.; Mueller, A.; Kantele, A.; Schunk, M.; Gascon, J.; Stich, A.; Hatz, C.; Caumes, E.; Grobusch, M. P.; Fleck, R.; Mockenhaupt, F. P.; Zanger, P.

2015-01-01

Staphylococcus aureus is emerging globally. Treatment of infections is complicated by increasing antibiotic resistance. We collected clinical data and swabs of returnees with skin and soft tissue infections (SSTI) at 13 travel-clinics in Europe (www.staphtrav.eu). Sixty-two percent (196/318) SSTI

Streptokinase Treatment Reverses Biofilm-Associated Antibiotic Resistance in Staphylococcus aureus

DEFF Research Database (Denmark)

Jørgensen, Nis Pedersen; Zobek, Natalia; Dreier, Cindy

2016-01-01

by combining antibiotic treatment with a fibrinolytic drug. We quantified S. aureus USA300 biofilms grown on peg-lids in brain heart infusion (BHI) broth with 0%–50% human plasma. Young (2 h) and mature (24 h) biofilms were then treated with streptokinase to determine if this lead to dispersal. Then......, the minimal biofilm eradication concentration (MBEC) of 24 h old biofilms was measured for vancomycin and daptomycin alone or in combination with 10 µg/mL rifampicin in the presence or absence of streptokinase in the antibiotic treatment step. Finally, biofilms were visualized by confocal laser scanning...... or daptomycin, which are commonly used antibiotics for treatment of S. aureus infections. Fibronolytic drugs have been used to treat thromboembolic events for decades, and our findings suggest that their use against biofilm infections has the potential to improve the efficacy of antibiotics in treatment of S...

Nasal Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage among college student athletes in northern Taiwan

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Hong-Kai Wang

2017-08-01

Full Text Available Of 259 college students in northern Taiwan surveyed, nasal carriage rate of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA was 22.4% and 1.54%, respectively and no significant difference was found between athlete students and non-athlete students. Three of four MRSA isolates belonged to sequence type 59, the endemic community clone.

Occurrence of vancomycin-resistant Staphylococcus aureus in the oral cavity of patients with dental caries.

Science.gov (United States)

Vellappally, Sajith; Divakar, Darshan Devang; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Alqahtani, Amer; Dalati, M H N; Anil, Sukumaran; Khan, Aftab Ahmed; Harikrishna Varma, P R

2017-09-01

Oral streptococci are the major group of microbes isolated from oral microflora. They represent frequent pathogens of infective endocarditis (IE), and it is assumed that in most of the cases oral streptococci are acquired via mucosa layer of oral cavity. Staphylococcus aureus is also frequently isolated from IE as it accounts for 20%-30% of all cases. Vancomycin has been the most reliable therapeutic agent against infections caused by methicillin-resistant S. aureus (MRSA). The main objective of this study was to examine the occurrence of S. aureus species in dental caries specimens. Antimicrobial susceptibility testing of S. aureus to four antibiotics namely vancomycin, linezolid, teicoplanin, and daptomycin was performed. Detection of vancomycin resistance was conducted using polymerase chain reaction. Among the tested 150 strains, 98 were MRSA and of that 54 were vancomycin sensitive and 27 were resistant. All 98 MRSA strains were positive for mecA and 36 yielded pvl, whereas 13 carried vanA and only 2 were positive for vanB. Majority of the isolates showed sensitivity toward daptomycin and linezolid. Strains of S. aureus exhibiting decreased susceptibility to different antibiotics like vancomycin, daptomycin, and linezolid severely compromise the therapeutic alternatives and require a considerable amount of time, public awareness, and integrative health-care strategies to prevent the emergence of resistance to these compounds.

Investigation of Antibiotic Susceptibility Pattern of Staphylococcus aureus Strains Isolated from Patients Referring to Some Treatment Centers of Qom City, Iran

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Sara Mosaei

2017-07-01

Full Text Available Background and Objectives: Staphylococcus aureus is one of the important causes of nosocomial infections. Resistance to various antibiotics, such as beta-lactams, aminoglycosides, and macrolides is one of the major problems in treatment and prevention of infections caused by this bacterium. Therefore, accurate determination of antibiotic susceptibility pattern of organisms isolated from patients can be beneficial in treatment and prevention of dangerous infections. The objective of this study was to isolate S. aureus bacterium and to determine the antibiotic susceptibility pattern of the isolated strains in patients referred to some treatment centers of Qom city. Methods: In this descriptive cross-sectional study, 340 clinical samples, were collected from September 2016 to July 2017. After isolation and primary identification of S. aureus isolates (using standard bacteriology methods, the isolated strains were confirmed by PCR technique and amplification of femA gene as a molecular diagnostic marker of S. aureus. Finally, antibiotic susceptibility pattern of the strains, was determined by disk diffusion method according to CLSI guideline. Results: Out of 340 clinical samples, 86 S. aureus strains were isolated and identified based on phenotypic characteristics. The femA gene was observed only in 45 strains (52.32% based on molecular analysis. The results of the antibiotic susceptibility test showed that the highest resistance was to penicillin (86.04% and the lowest resistance was to chloramphenicol (0%. Conclusion: The results of this study indicated that femA gene cannot by itself identify all the S. aureus strains. Also, with regard to the results of antibiogram test, it seems that antibiotic susceptibility test is necessary for S. aureus strains isolated from patients.

Staphylococcus aureus endocarditis with fast development of aortic root abscess despite relevant antibiotics

DEFF Research Database (Denmark)

Dahl, Anders; Hansen, Thomas Fritz; Bruun, Niels Eske

2013-01-01

We present a case of Staphylococcus aureus endocarditis in which a large abscess was formed in only 4 days, despite specific intravenous antibiotics and only few vague signs of disease progression. Our case seems to be the first to show echocardiographic documentation of how quickly an intracardiac...... abscess can develop despite relevant antibiotics. Clinically, the patient is remarkably unaffected, and thus even small signs of progression should lead to considerations about repeating the diagnostic imaging workup. This case illustrates how aggressive an infection S. aureus endocarditis may be...

In vitro Antibacterial Activity of Mentha Essential Oils Against Staphylococcus aureus

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Horváth P.

2017-09-01

Full Text Available Plant extracts and essential oils (EOs are characterized by their antibacterial properties against various bacterial pathogens, including staphylococci. Some strains of these bacteria are resistant against the adverse effects of the environment including antibiotics, e. g. methicillin-resistant Staphylococcus aureus (MRSA. EOs alone cannot substitute for antibiotics but their treatment may be useful to intensify and strengthen the effects of antibiotics on pathogenic staphylococci. In this work, we tested the antibacterial effects of the essential oils of Mentha species with menthol as one of the effective substances against different strains of S. aureus. Two in vitro methods were used, the qualitative disc diffusion assay and the quantitative minimal inhibitory concentration (MIC of selected essential oils. Peppermint oil from Mentha piperita, spearmint oil from Mentha spicata var. crispa and cornmint oil from Mentha arvensis were tested in this study against the various strains of Staphylococcus aureus, including methicillin resistant Staphylococcus aureus (MRSA. The oils were dissolved in DMSO (dimethyl sulfoxide and diluted at the following ratios: 1 : 1, 1 : 2, 1 : 5, and 1 : 10. Based on the results determined by the agar disc diffusion test, the highest antibacterial properties were observed in spearmint oil against S. aureus CCM 4223 at 1 : 2 ratio where the inhibition zone varied at a range of 35.67 ± 6.81 mm. We determined also the MIC of all the oils where concentrations of the oils were as follows: 1 %; 0.5 %; 0.25 %; 0.125 % and 0.0625 %. The lowest concentrations of essential oils that possessed inhibitory effects on the growth of S. aureus varied between 0.125 % and 0.25 %.

Nasal carriage of multi-drug resistant Staphylococcus aureus in ...

African Journals Online (AJOL)

Background: Nasal Staphylococcus aureus is a major source of community and hospital associated staphylococcal infections. This study determined the prevalence of nasal S. aureus isolates and investigated their antimicrobial resistance profile in healthy volunteers. Methods: Nasal specimens of healthy volunteers in ...

Characterization of Staphylococcus aureus isolates from retail chicken carcasses and pet workers in Northwest Arkansas.

Science.gov (United States)

Hanning, Irene; Gilmore, David; Pendleton, Sean; Fleck, Scott; Clement, Ashley; Park, Si Hong; Scott, Erin; Ricke, Steven C

2012-01-01

Staphylococcus aureus can be carried on the skin and nasal passages of humans and animals as a commensal. A case of human methicillin-resistant S. aureus infection resulting from contact with pork has been reported. Poultry carcasses are sold at retail with the skin intact, but pork and beef typically are not. Thus, the risk of methicillin-resistant S. aureus human infection from whole raw poultry carcasses may be greater than that of exposure from pork or beef. The objective of this study was to isolate and characterize S. aureus from whole retail poultry carcasses and compare the isolates to S. aureus isolates from humans. A total of 25 S. aureus isolates were collected from 222 whole poultry carcasses. The isolates were characterized phenotypically with antibiotic resistance disc diffusion assays and genotypically using multilocus sequence typing. A total of 17 S. aureus isolates obtained from healthy humans were included and characterized in the same way as the poultry isolates. Staphylococcus spp. were recovered from all poultry carcasses. Only 25 poultry carcasses (11.2%) were contaminated with S. aureus. Of these 25 isolates, 36% were resistant to at least one of the antibiotics tested and 20% were resistant to two or more antibiotics tested. However, 100% of the human isolates were resistant to at least one of the antibiotics and 94% were resistant to two or more antibiotics. The results of the multilocus sequence typing indicate that most of the isolates grouped according to source. These results indicate a low prevalence of S. aureus present in poultry, and the isolates were not phenotypically similar to human isolates. The low number of S. aureus isolates from this study indicates that chicken carcasses would appear to not be a significant source of this bacterium.

Nasal carriage of Methicillin-resistant Staphylococcus aureus among healthy population of Kashmir, India

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B A Fomda

2014-01-01

Full Text Available Background: Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA colonising anterior nares of healthy subjects. Materials and Methods: Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE. Results: Out of 820 samples, S.aureus was isolated from 229 (27.92% subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis. Conclusion: High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

The impact of meticillin-resistant Staphylococcus aureus on patients with advanced cancer and their family members: A qualitative study.

Science.gov (United States)

Gleeson, Aoife; Larkin, Philip; O'Sullivan, Niamh

2016-04-01

Little is known about the impact of meticillin-resistant Staphylococcus aureus on patients with advanced cancer, such as its impact on the quality of life of this vulnerable group. To date, research on meticillin-resistant Staphylococcus aureus in the palliative care setting has had a quantitative focus. The purpose of this study was to explore the impact of a meticillin-resistant Staphylococcus aureus diagnosis on patients and their carers. This article reports upon a qualitative interview study of nine patients with advanced cancer and meticillin-resistant Staphylococcus aureus and nine family members (n = 18). Framework analysis was used to analyse the data. Patients and family members of patients with advanced cancer either admitted to the specialist palliative care unit or receiving palliative care in the hospital setting, who had a laboratory confirmed diagnosis of meticillin-resistant Staphylococcus aureus colonisation, were considered for inclusion in the study. Four themes were identified using framework analysis: reactions to receiving a meticillin-resistant Staphylococcus aureus diagnosis, the need for effective communication of the meticillin-resistant Staphylococcus aureus diagnosis, the enigmatic nature of meticillin-resistant Staphylococcus aureus, and lessons to guide the future care of meticillin-resistant Staphylococcus aureus patients. This article indicates that meticillin-resistant Staphylococcus aureus can have a significant impact on advanced cancer patients and their families. This impact may be underestimated, but early and careful face-to-face explanation about meticillin-resistant Staphylococcus aureus and its implications can help patients and their families to cope better with it. These findings should be considered when developing policy relating to meticillin-resistant Staphylococcus aureus management and infection control in specialist palliative care settings. © The Author(s) 2015.

Novel bacterial metabolite merochlorin A demonstrates in vitro activity against multi-drug resistant methicillin-resistant Staphylococcus aureus.

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George Sakoulas

Full Text Available We evaluated the in vitro activity of a merochlorin A, a novel compound with a unique carbon skeleton, against a spectrum of clinically relevant bacterial pathogens and against previously characterized clinical and laboratory Staphylococcus aureus isolates with resistance to numerous antibiotics.Merochlorin A was isolated and purified from a marine-derived actinomycete strain CNH189. Susceptibility testing for merochlorin A was performed against previously characterized human pathogens using broth microdilution and agar dilution methods. Cytotoxicity was assayed in tissue culture assays at 24 and 72 hours against human HeLa and mouse sarcoma L929 cell lines.The structure of as new antibiotic, merochlorin A, was assigned by comprehensive spectroscopic analysis. Merochlorin A demonstrated in vitro activity against Gram-positive bacteria, including Clostridium dificile, but not against Gram negative bacteria. In S. aureus, susceptibility was not affected by ribosomal mutations conferring linezolid resistance, mutations in dlt or mprF conferring resistance to daptomycin, accessory gene regulator knockout mutations, or the development of the vancomycin-intermediate resistant phenotype. Merochlorin A demonstrated rapid bactericidal activity against MRSA. Activity was lost in the presence of 20% serum.The unique meroterpenoid, merochlorin A demonstrated excellent in vitro activity against S. aureus and C. dificile and did not show cross-resistance to contemporary antibiotics against Gram positive organisms. The activity was, however, markedly reduced in 20% human serum. Future directions for this compound may include evaluation for topical use, coating biomedical devices, or the pursuit of chemically modified derivatives of this compound that retain activity in the presence of serum.

Curcumin Reverse Methicillin Resistance in Staphylococcus aureus

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Su-Hyun Mun

2014-11-01

Full Text Available Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., was shown to possess superior potency to resensitize methicillin-resistant Staphylococcus aureus (MRSA to antibiotics. Previous studies have shown the synergistic activity of curcumin with β-lactam and quinolone antibiotics. Further, to understand the anti-MRSA mechanism of curcumin, we investigated the potentiated effect of curcumin by its interaction in diverse conditions. The mechanism of anti-MRSA action of curcumin was analyzed by the viability assay in the presence of detergents, ATPase inhibitors and peptidoglycan (PGN from S. aureus, and the PBP2a protein level was analyzed by western blotting. The morphological changes in the curcumin-treated MRSA strains were investigated by transmission electron microscopy (TEM. We analyzed increased susceptibility to MRSA isolates in the presence of curcumin. The optical densities at 600 nm (OD600 of the suspensions treated with the combinations of curcumin with triton X-100 and Tris were reduced to 63% and 59%, respectively, compared to curcumin without treatment. N,N'-dicyclohexylcarbodiimide (DCCD and sodium azide (NaN3 were reduced to 94% and 55%, respectively. When peptidoglycan (PGN from S. aureus was combined with curcumin, PGN (0–125 μg/mL gradually blocked the antibacterial activity of curcumin (125 μg/mL; however, at a concentration of 125 µg/mL PGN, it did not completely block curcumin. Curcumin has a significant effect on the protein level of PBP2a. The TEM images of MRSA showed damage of the cell wall, disruption of the cytoplasmic contents, broken cell membrane and cell lysis after the treatment of curcumin. These data indicate a remarkable antibacterial effect of curcumin, with membrane permeability enhancers and ATPase inhibitors, and curcumin did not directly bind to PGN on the cell wall. Further, the antimicrobial action of curcumin involved in the PBP2a-mediated resistance mechanism was

Methicillin-resistant Staphylococcus aureus prevention strategies in the ICU: a clinical decision analysis*.

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Ziakas, Panayiotis D; Zacharioudakis, Ioannis M; Zervou, Fainareti N; Mylonakis, Eleftherios

2015-02-01

ICUs are a major reservoir of methicillin-resistant Staphylococcus aureus. Our aim was to estimate costs and effectiveness of methicillin-resistant Staphylococcus aureus prevention policies. We evaluated three up-to-date methicillin-resistant Staphylococcus aureus prevention policies, namely, 1) nasal screening and contact precautions of methicillin-resistant Staphylococcus aureus-positive patients; 2) nasal screening, contact precautions, and decolonization (targeted decolonization) of methicillin-resistant Staphylococcus aureus carriers; and 3) universal decolonization without screening. We implemented a decision-analytic model with deterministic and probabilistic analyses. Methicillin-resistant Staphylococcus aureus infections averted, quality-adjusted life years gained, and incremental cost-effectiveness ratios were calculated. Cost-effectiveness planes and acceptability curves were plotted for various willingness-to-pay thresholds to address uncertainty. At base-case scenario, universal decolonization was the dominant strategy; it averted 1.31% and 1.59% of methicillin-resistant Staphylococcus aureus infections over targeted decolonization and screening and contact precautions, respectively, and saved $16,203/quality-adjusted life year over targeted decolonization and 14,562/quality-adjusted life year over screening and contact precautions. Results were robust in sensitivity analysis for a wide range of input variables. In probabilistic analysis, universal decolonization increased quality-adjusted life years by 1.06% (95% CI, 1.02-1.09) over targeted decolonization and by 1.29% (95% CI, 1.24-1.33) over screening and contact precautions; universal decolonization resulted in average savings of $172 (95% CI, $168-$175) and $189 (95% CI, $185-$193) over targeted decolonization and screening and contact precautions, respectively. With willingness-to-pay threshold per quality-adjusted life year gained ranging from $0 to $50,000, universal decolonization was dominant

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci.

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McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M; Zhang, Kunyan

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus ), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. Copyright © 2017 American Society for Microbiology.

Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice.

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Harkins, Catriona P; Pichon, Bruno; Doumith, Michel; Parkhill, Julian; Westh, Henrik; Tomasz, Alexander; de Lencastre, Herminia; Bentley, Stephen D; Kearns, Angela M; Holden, Matthew T G

2017-07-20

The spread of drug-resistant bacterial pathogens poses a major threat to global health. It is widely recognised that the widespread use of antibiotics has generated selective pressures that have driven the emergence of resistant strains. Methicillin-resistant Staphylococcus aureus (MRSA) was first observed in 1960, less than one year after the introduction of this second generation beta-lactam antibiotic into clinical practice. Epidemiological evidence has always suggested that resistance arose around this period, when the mecA gene encoding methicillin resistance carried on an SCCmec element, was horizontally transferred to an intrinsically sensitive strain of S. aureus. Whole genome sequencing a collection of the first MRSA isolates allows us to reconstruct the evolutionary history of the archetypal MRSA. We apply Bayesian phylogenetic reconstruction to infer the time point at which this early MRSA lineage arose and when SCCmec was acquired. MRSA emerged in the mid-1940s, following the acquisition of an ancestral type I SCCmec element, some 14 years before the first therapeutic use of methicillin. Methicillin use was not the original driving factor in the evolution of MRSA as previously thought. Rather it was the widespread use of first generation beta-lactams such as penicillin in the years prior to the introduction of methicillin, which selected for S. aureus strains carrying the mecA determinant. Crucially this highlights how new drugs, introduced to circumvent known resistance mechanisms, can be rendered ineffective by unrecognised adaptations in the bacterial population due to the historic selective landscape created by the widespread use of other antibiotics.

Improved understanding of factors driving methicillin-resistant Staphylococcus aureus epidemic waves

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Chatterjee, Som S; Otto, Michael

2013-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most important causes of nosocomial infections worldwide. Since the global spread of MRSA in the 1960s, MRSA strains have evolved with increased pathogenic potential. Notably, some strains are now capable of causing persistent infections not only in hospitalized patients but also in healthy individuals in the community. Furthermore, MRSA is increasingly associated with infections among livestock-associated workers, primarily because of transmission from animals to humans. Moreover, many MRSA strains have gained resistance to most available antibiotics. In this review, we will present current knowledge on MRSA epidemiology and discuss new endeavors being undertaken to understand better the molecular and epidemiological underpinnings of MRSA outbreaks. PMID:23861600

Fighting antibiotic resistance in the intensive care unit using antibiotics.

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Plantinga, Nienke L; Wittekamp, Bastiaan H J; van Duijn, Pleun J; Bonten, Marc J M

2015-01-01

Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to classical infection prevention protocols and surveillance programs, counterintuitive interventions, such as selective decontamination with antibiotics and antibiotic rotation have been applied and investigated to control the emergence of antibiotic resistance. This review provides an overview of selective oropharyngeal and digestive tract decontamination, decolonization of methicillin-resistant Staphylococcus aureus and antibiotic rotation as strategies to modulate antibiotic resistance in the intensive care unit.

Prevalence of Methicillin Resistant Staphylococcus aureus in Clinical Samples of Teerthankar Mahaveer Medical College Hospital and Research Centre (TMMCH & RC, Moradabad (UP, India

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Bina Pani Gupta

2017-06-01

Full Text Available Staphylococcus aureus is the emerging and prevalent pathogen causing serious infections in community and hospital associated diseases. S. aureus resistant to methicillin is nowadays a big and expanding problem of concern in India. Amongst the different pathogens, S. aureus is being studied for prevalence of infections and drug resistance behavior. The present study describes the dominance of Staphylococcus aureus prevalence in the clinical samples of TMU, Moradabad, India. The study showed the isolation of 450 cultures of S. aureus from different samples. Amongst which, 234 isolates of S. aureus were from pus, 164 isolates were from blood, 15 isolates were from respiratory fluid samples, 33 isolates were from urine samples and 04 isolates were from ear swabs and nasal swabs. These strains of S. aureus were screened for characteristic coagulase assay. The strains were found to be coagulase positive and coagulases negative both. It was observed that, amongst, 450 isolates of Staphylococci, 185 (41.11% strains were coagulase positive and 265 (58.88% were coagulase negative. A total of 142 (76.75% of the coagulase positive staphylococci strains shows resistance to methicillin and 202 (76.22% coagulase negative strains showed methicillin resistance. Methicillin resistance was consistent when tested with other antibiotics in coagulase positive strains but when studied about coagulase negative strains, about 12.5% strains showed sensitivity with other antibiotics although they were found resistant when checked with methicillin. It was determined that, on an average, 85 (18.88% Staphylococci strains were resistant.

Prolonged exposure of methicillin-resistant Staphylococcus aureus (MRSA) COL strain to increasing concentrations of oxacillin results in a multidrug-resistant phenotype

DEFF Research Database (Denmark)

Martins, Ana; Couto, Isabel; Aagaard, Lone

2007-01-01

Our previous studies demonstrated that exposure of a bacterium to increasing concentrations of an antibiotic would increase resistance to that antibiotic as a consequence of activating efflux pumps. This study utilises the same approach; however, it employs the methicillin-resistant Staphylococcus...... aureus (MRSA) COL strain, which is highly resistant to oxacillin (OXA). MRSA COL was adapted to 3200 mg/L of OXA. Changes in resistance to other antibiotics were evaluated and efflux pump activity during the adaptation process was determined. MRSA COL was exposed to stepwise two-fold increases of OXA....... At the end of each step, minimum inhibitory concentration determination for erythromycin (ERY) and other antibiotics was conducted. Reserpine (RES) was employed to evaluate whether resistance to ERY was dependent on efflux pump activity. Efflux pump activity was also evaluated using the ethidium bromide (EB...

Daptomycin approved in Japan for the treatment of methicillin-resistant Staphylococcus aureus

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Mori T

2012-02-01

Full Text Available Mao Hagihara1, Takumi Umemura1, Takeshi Mori1,2, Hiroshige Mikamo11Department of Infection Control and Prevention, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan; 2Division of Pharmaceutical Science, Faculty of Pharmacy, Meijo University, Nagoya, Aichi, JapanAbstract: Daptomycin is a lipoglycopeptide antibacterial drug that is rapidly bactericidal for methicillin-resistant Staphylococcus aureus (MRSA infection and has antibiotic activity against a wide range of Gram-positive organisms. It has been approved by the Ministry of Health, Labor and Welfare in Japan for the treatment for bacteremia, right-sided endocarditis, and skin and skin-structure infections, such as necrotizing fasciitis, due to MRSA on the basis of a Phase III trial conducted in Japan since July, 2011. In Japanese Phase I and III trials, daptomycin therapy given at 4 mg/kg and 6 mg/kg once per day was well tolerated and effective as standard therapy for the treatment of acute bacterial skin and skin-structure infections and bacteremia caused by MRSA, but side effects remain to be evaluated in large-scale trials.Keywords: daptomycin, methicillin-resistant Staphylococcus aureus (MRSA, Japan

A study of Staphylococcus aureus nasal carriage, antibacterial ...

African Journals Online (AJOL)

Aim: This study was to determine the virulence encoding genes, and the antibiotic resistance patterns of the Staphylococcus aureus isolates, which were isolated from the nasal samples of chest clinic patients. Materials and Methods: The nasal samples of the in‑patients (431) and out‑patients (1857) in Kayseri Training and ...

PREVALENCE AND ANTIBIOTIC RESISTANCE OF ...

African Journals Online (AJOL)

9 mars 2015 ... strategy to prevent the spread of this resistance. Keywords: Staphylococci; Staphylococcus aureus; Oxacillin; Antibiotic resistance; Disc diffusion. Author Correspondence, e-mail: mn.boukhatem@yahoo.fr. ICID: 1142924. Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at.

Efficacy of antibiotic treatment of implant-associated Staphylococcus aureus infections with moxifloxacin, flucloxacillin, rifampin, and combination therapy: an animal study

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Greimel F

2017-06-01

Full Text Available Felix Greimel,1 Christine Scheuerer,1 Andre Gessner,2 Michaela Simon,2 Thomas Kalteis,1 Joachim Grifka,1 Achim Benditz,1 Hans-Robert Springorum,1 Jens Schaumburger1 1Department of Orthopedics, University Medical Center Regensburg, Asklepios Klinikum Bad Abbach, Bad Abbach, 2Institute of Clinical Microbiology and Hygiene, University Medical Center Regensburg, Regensburg, Bavaria, Germany Abstract: The efficacy of antibiotic monotherapy and combination therapy in the treatment of implant-associated infection by Staphylococcus aureus was evaluated in an animal study. The femoral medullary cavity of 66 male Wistar rats was contaminated with S. aureus (ATCC 29213 and a metal device was implanted, of which 61 could be evaluated. Six treatment groups were studied: flucloxacillin, flucloxacillin in combination with rifampin, moxifloxacin, moxifloxacin in combination with rifampin, rifampin, and a control group with aqua. The treatment was applied for 14 days. After euthanasia, the bacterial counts in the periprosthetic bone, the soft tissue, and the implant-associated biofilm were measured. Both antibiotic combination treatments (moxifloxacin plus rifampin and flucloxacillin plus rifampin achieved a highly significant decrease in microbial counts in the bone and soft tissue and in the biofilm. Mono-antibiotic treatments with either moxifloxacin or flucloxacillin were unable to achieve a significant decrease in microbial counts in bone and soft tissue or the biofilm, whilst rifampin was able to reduce the counts significantly only in the biofilm. Antibiotic resistance was measured in 1/3 of the cases in the rifampin group, whereas no resistance was measured in all other groups. The results show that combinations of both moxifloxacin and flucloxacillin plus rifampin are adequate for the treatment of periprosthetic infections due to infections with S. aureus, whereas monotherapies are not effective or not applicable due to the rapid development of

Multiple drug resistance Staphylococcus aureus isolated in foods of ...

African Journals Online (AJOL)

Background: StaphylococcuS. aureus is the most important agent, which is known to cause a wide range of diseases in both human and animals. Extended use and misuse of antibiotics in agriculture, stock farming and in the treatment of human diseases, has contributed to the rapid increase of the number of bacteria that ...

Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes

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Suat Moi Puah

2016-02-01

Full Text Available Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52 of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5% and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines.

Nasal Carriage Rate of Methicillin Resistant Staphylococcus aureus among Health Care Workers at a Tertiary Care Hospital in Kathmandu, Nepal.

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Khatri, S; Pant, N D; Bhandari, R; Shrestha, K L; Shrestha, C D; Adhikari, N; Poudel, A

2017-01-01

Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections. Due to its multidrug resistant nature; infections due to Methicillin-resistant Staphylococcus aureus are often very difficult to treat. Colonized health care workers are the important sources of Methicillin-resistant Staphylococcus aureus. The objectives of this study were to determine the nasal carriage rate of Methicillin-resistant Staphylococcus aureus among health care workers at Kathmandu Medical College and Teaching Hospital, Nepal and to assess their antimicrobial susceptibility patterns. A cross sectional study was conducted among 252 health care workers from July to November 2013. Mannitol salt agar was used to culture the nasal swabs. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique following Clinical and Laboratory Standards Institute guidelines. Methicillin-resistant Staphylococcus aureus strains were confirmed by using cefoxitin disc and by determining the minimum inhibitory concentration of oxacillin by agar dilution method. Of 252 healthcare workers, 46(18.3%) were positive for Staphylococcus aureus among which 19(41.3%) were Methicillin-resistant Staphylococcus aureus carriers. Overall rate of nasal carriage of Methicillin-resistant Staphylococcus aureus was 7.5% (19/252).The higher percentages of lab personnel were nasal carriers of S. aureus (31.6%) and Methicillin-resistant Staphylococcus aureus (10.5%).The percentages of nasal carriage of S. aureus (35.7%) and Methicillin-resistant Staphylococcus aureus (14.3%) were highest in the health care workers from post operative department. Higher percentage of Methicillin-resistant Staphylococcus aureus were susceptible toward amikacin (100%) and vancomycin (100%) followed by cotrimoxazole (84.2%). High rates of nasal carriage of S. aureus and Methicillin-resistant Staphylococcus aureus were observed among the healthcare workers, which indicate the need of

Mesosomes are a definite event in antibiotic-treated Staphylococcus aureus ATCC 25923.

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Santhana Raj, L; Hing, H L; Baharudin, Omar; Teh Hamidah, Z; Aida Suhana, R; Nor Asiha, C P; Vimala, B; Paramsarvaran, S; Sumarni, G; Hanjeet, K

2007-06-01

Mesosomes of Staphylococcus aureus ATCC 25923 treated with antibiotics were examined morphologically under the electron microscope. The Transmission Electron Microscope Rapid Method was used to eliminate the artifacts due to sample processing. Mesosomes were seen in all the antibiotic treated bacteria and not in the control group. The main factor that contributes to the formation of mesosomes in the bacteria was the mode of action of the antibiotics. The continuous cytoplasmic membrane with infolding (mesosomes) as in the S. aureus ATCC 25923 is therefore confirmed as a definite pattern of membrane organization in gram positive bacteria assaulted by amikacin, gentamicin, ciprofloxacin, vancomycin and oxacillin antibiotics. Our preliminary results show oxacillin and vancomycin treated bacteria seemed to have deeper and more mesosomes than those treated with amikacin, gentamicin and ciprofloxacin. Further research is needed to ascertain whether the deep invagination and the number of mesosomes formed is associated with the types of antibiotic used.

Six-Year Retrospective Review of Hospital Data on Antimicrobial Resistance Profile of Staphylococcus aureus Isolated from Skin Infections from a Single Institution in Greece

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Christina Stefanaki

2017-12-01

Full Text Available Objective: To determine the prevalence of resistant strains of Staphylococcus aureus (S. aureus isolated from Skin and soft tissue infections (SSTI to various antibiotics. Material and Methods: All culture-positive results for S. aureus from swabs taken from patients presenting at one Greek hospital with a skin infection between the years 2010–2015 were examined retrospectively. Bacterial cultures, identification of S. aureus and antimicrobial susceptibility testing were performed using the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI guidelines and European Committee on Antimicrobial testing (EUCAST breakpoints. EUCAST breakpoints were applied if no CLSI were available. Results: Of 2069 S. aureus isolates identified, 1845 (88% were resistant to one or more antibiotics. The highest resistance was observed for benzylpenicillin (71.9%, followed by erythromycin (34.3%. Resistant strains to cefoxitin defined as MRSA (methicillin-resistant S. aureus represented 21% of total isolates. Interestingly, resistance to fusidic acid was 22.9% and to mupirocin as high as 12.7%. Low rates were observed for minocycline, rifampicin and trimethoprim/sulfamethoxazole (SXT. Resistance to antibiotics remained relatively stable throughout the six-year period, with the exception of cefoxitin, fusidic acid and SXT. A high percentage of MRSA strains were resistant to erythromycin (60%, fusidic acid (46%, clindamycin (38% and tetracycline (35.5%. Conclusions: Special attention is required in prescribing appropriate antibiotic therapeutic regimens, particularly for MRSA. These data on the susceptibility of S. aureus may be useful for guiding antibiotic treatment.

Spread of community-acquired meticillin-resistant Staphylococcus aureus skin and soft-tissue infection within a family: implications for antibiotic therapy and prevention.

LENUS (Irish Health Repository)

Amir, N H

2010-04-01

Outbreaks or clusters of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) within families have been reported. We describe a family cluster of CA-MRSA skin and soft-tissue infection where CA-MRSA was suspected because of recurrent infections which failed to respond to flucloxacillin. While the prevalence of CA-MRSA is low worldwide, CA-MRSA should be considered in certain circumstances depending on clinical presentation and risk assessment. Surveillance cultures of family contacts of patients with MRSA should be considered to help establish the prevalence of CA-MRSA and to inform the optimal choice of empiric antibiotic treatment.

Prevalence of the antibiotic resistance genes in coagulase-positive- and negative-Staphylococcus in chicken meat retailed to consumers

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Kamelia Mahmoud Osman

2016-11-01

Full Text Available The use of antibiotics in farm management (growing crops and raising animals has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA, methicillin-resistant S. aureus (MRSA, methicillin-resistant coagulase-negative staphylococci (MRCNS and methicillin-susceptible coagulase-negative staphylococci (MSCNS isolated from the retail trade of ready-to-eat raw chicken meat samples collected during one year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim and vancomycin and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14 and CNS (36, representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius and S. lentus. Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides and streptogramin B (MLS(B in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance

Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers.

Science.gov (United States)

Osman, Kamelia; Badr, Jihan; Al-Maary, Khalid S; Moussa, Ihab M I; Hessain, Ashgan M; Girah, Zeinab M S Amin; Abo-Shama, Usama H; Orabi, Ahmed; Saad, Aalaa

2016-01-01

The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mec A and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mec A and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species ( S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius , and S. lentus ). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mec A gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS( B )] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance

Prevalence and resistance of commensal Staphylococcus aureus, including meticillin-resistant S aureus, in nine European countries: a cross-sectional study.

NARCIS (Netherlands)

Heijer, C.D.J. den; Bijnen, E.M.E. van; Paget, W.J.; Pringle, M.; Goossen, H.; Bruggeman, C.A.; Schellevis, F.G.; Stobberingh, E.E.

2013-01-01

Background: Information about the prevalence of Staphylococcus aureus resistance to antimicrobial drugs has mainly been obtained from invasive strains, although the commensal microbiota is thought to be an important reservoir of resistance. We aimed to compare the prevalence of nasal S aureus

Changes of Antimicrobial Resistance among Staphylococcus Aureus Isolated in 8 Consecutive Years in the First Bethune Hospital

Science.gov (United States)

Xu, Wei; Zhou, Qi; Yang, Chunguang; Yao, Hanxin; Xu, Jiancheng

This study was to investigate the antimicrobial resistance of Staphylococcus aureus isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 1469 strains of Staphylococcus aureus were collected from sputum 705 (18.0%), secretions 206 (14.0%), pus 177 (12.0%) during the past 8 years. The rates of methicillin-resistant Staphylococcus aureus (MRSA) were between 50.8% and 83.3% during the past 8 years, respectively. In recent 8 years, the antimicrobial resistance of Staphylococcus aureus had increased. Monitoring the antimicrobial resistance to Staphylococcus aureus should be strengthened. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from being transmitted.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA ...

African Journals Online (AJOL)

One of each duplicate swab sample was inoculated directly onto chocolate agar, incubated for 24 hours at 37oc while the other swab was used to make a smear for Gram staining. All isolates were identified using standard microbiological methods. Staphylococcus aureus isolates were screened for methicillin resistance ...

The Role of Antibiotics in Modulating Virulence in Staphylococcus aureus.

Science.gov (United States)

Hodille, Elisabeth; Rose, Warren; Diep, Binh An; Goutelle, Sylvain; Lina, Gerard; Dumitrescu, Oana

2017-10-01

Staphylococcus aureus is often involved in severe infections, in which the effects of bacterial virulence factors have great importance. Antistaphylococcal regimens should take into account the different effects of antibacterial agents on the expression of virulence factors and on the host's immune response. A PubMed literature search was performed to select relevant articles on the effects of antibiotics on staphylococcal toxin production and on the host immune response. Information was sorted according to the methods used for data acquisition (bacterial strains, growth models, and antibiotic concentrations) and the assays used for readout generation. The reported mechanisms underlying S. aureus virulence modulation by antibiotics were reviewed. The relevance of in vitro observations is discussed in relation to animal model data and to clinical evidence extracted from case reports and recommendations on the management of toxin-related staphylococcal diseases. Most in vitro data point to a decreased level of virulence expression upon treatment with ribosomally active antibiotics (linezolid and clindamycin), while cell wall-active antibiotics (beta-lactams) mainly increase exotoxin production. In vivo studies confirmed the suppressive effect of clindamycin and linezolid on virulence expression, supporting their utilization as a valuable management strategy to improve patient outcomes in cases of toxin-associated staphylococcal disease. Copyright © 2017 American Society for Microbiology.

Several Virulence Factors of Multidrug-Resistant Staphylococcus aureus Isolates From Hospitalized Patients in Tehran

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Abdolmajid Ghasemian

2015-05-01

Full Text Available Background: Biofilm formation plays an important role in resistance of Staphylococcus aureus isolates; especially multidrug-resistant isolates are a threat to healthcare settings. Objectives: The aims of this study were to detect biofilm formation and presence of several related genes among multidrug-resistant (MDR isolates of Staphylococcus aureus. Patients and Methods: A total Of 209 S. aureus strains were isolated from patients and identified by conventional diagnostic tests. The multidrug-resistant MRSA isolates were detected by antibiotic susceptibility test. The phenotypic biofilm formation was detected by micro-titre tissue plate assay. The polymerase chain reaction (PCR was performed to detect the mecA, Staphylococcal Cassette Chromosome mec (SCCmec types, accessory gene regulatory (agr genes, the icaADBC and several genes encoding staphylococcal surface proteins including clfAB, fnbAB, fib, eno, can, ebps and bbp genes with specific primers. Results: Sixty-four (30.6% isolates were methicillin-resistant, among which thirty-six (56.2% were MDR. These isolates were resistant to amoxicillin, tetracycline, ciprofloxacin, gentamicin, erythromycin and trimethoprim-sulfamethoxazole (except to 6 isolates. All the isolates were susceptible to vancomycin and linezolid. All the MDR-MRSA harbored SCCmec type III. All the MDR- MRSA isolates were strong biofilm producers in the phenotypic test. The majority of MDR- MRSA was belonged to agrI (67%, n = 24, followed by agr II (17%, n = 6, agrIV (11%, n = 4 and agrIII (5.5%, n = 2. The frequency of icaADBC genes were 75% (n = 27, 61% (n = 22, 72% (n = 26 and 72% (n = 26, respectively. Furthermore, the prevalence of clfA, clfB, fnbA, fnbB, fib, can, eno, ebps and bbp genes was 100%, 100%, 67%, 56%, 80%, 63%, 78%, 7% and 0%, respectively. Furthermore, approximately all the MRSA was strong biofilm producers. Conclusions: Multidrug-resistant isolates produced biofilm strongly and the majority harbored most

5-aminolevulinic acid-mediated photodynamic therapy and its strain-dependent combined effect with antibiotics on Staphylococcus aureus biofilm.

Directory of Open Access Journals (Sweden)

Qing-Zhao Zhang

Full Text Available Staphylococcus aureus (S. aureus is hard to be eradicated, not only due to the emergence of antibiotic resistant strains but also because of its ability to form biofilm. Antibiotics are the major approach to treating biofilm infections, but their effects are unsatisfactory. One of the potential alternative treatments for controlling biofilm infections is photodynamic therapy (PDT, which requires the administration of photosensitizer, followed by light activation. 5-aminolevulinic acid (ALA, a natural photosensitizer prodrug, presents favorable characteristics, such as easy penetration and rapid clearance. These advantages enable ALA-based PDT (ALA-PDT to be well-tolerated by patients and it can be repeatedly applied without cumulative toxicity or serious side effects. ALA-PDT has been proven to be an effective treatment for multidrug resistant pathogens; however, the study of its effect on S. aureus biofilm is limited. Here, we established our PDT system based on the utilization of ALA and a light-emitting diode, and we tested the effect of ALA-PDT on S. aureus biofilm as well as the combined effect of ALA-PDT and antibiotics on S. aureus biofilm. Our results showed that ALA-PDT has a strong antibacterial effect on S. aureus biofilm, which was confirmed by the confocal laser scanning microscope. We also found that lethal photosensitization occurred predominantly in the upper layer of the biofilm, while the residual live bacteria were located in the lower layer of the biofilm. In addition, the improved bactericidal effect was observed in the combined treatment group but in a strain-dependent manner. Our results suggest that ALA-PDT is a potential alternative approach for future clinical use to treat S. aureus biofilm-associated infections, and some patients may benefit from the combined treatment of ALA-PDT and antibiotics, but drug sensitivity testing should be performed in advance.

Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

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Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A

2015-04-01

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F(2,238) = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses.

Characterisation of virulence genes in methicillin susceptible and resistant Staphylococcus aureus isolates from a paediatric population in a university hospital of Medellín, Colombia

OpenAIRE

Jiménez,Judy Natalia; Ocampo,Ana María; Vanegas,Johanna Marcela; Rodríguez,Erika Andrea; Garcés,Carlos Guillermo; Patiño,Luz Adriana; Ospina,Sigifredo; Correa,Margarita María

2011-01-01

Virulence and antibiotic resistance are significant determinants of the types of infections caused by Staphylococcus aureus and paediatric groups remain among the most commonly affected populations. The goal of this study was to characterise virulence genes of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains isolated from a paediatric population of a Colombian University Hospital during 2009. Sixty MSSA and MRSA isolates were obtained from paediatric...

Genotypic and Phenotypic Markers of Livestock-Associated Methicillin-Resistant Staphylococcus aureus CC9 in Humans.

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Ye, Xiaohua; Wang, Xiaolin; Fan, Yanping; Peng, Yang; Li, Ling; Li, Shunming; Huang, Jingya; Yao, Zhenjiang; Chen, Sidong

2016-07-01

Use of antimicrobials in industrial food animal production is associated with the presence of multidrug-resistant Staphylococcus aureus among animals and humans. The livestock-associated (LA) methicillin-resistant S. aureus (MRSA) clonal complex 9 (CC9) is associated with animals and related workers in Asia. This study aimed to explore the genotypic and phenotypic markers of LA-MRSA CC9 in humans. We conducted a cross-sectional study of livestock workers and controls in Guangdong, China. The study participants responded to a questionnaire and provided a nasal swab for S. aureus analysis. The resulting isolates were assessed for antibiotic susceptibility, multilocus sequence type, and immune evasion cluster (IEC) genes. Livestock workers had significantly higher rates of S. aureus CC9 (odds ratio [OR] = 30.98; 95% confidence interval [CI], 4.06 to 236.39) and tetracycline-resistant S. aureus (OR = 3.26; 95% CI, 2.12 to 5.00) carriage than controls. All 19 S. aureus CC9 isolates from livestock workers were MRSA isolates and also exhibited the characteristics of resistance to several classes of antibiotics and absence of the IEC genes. Notably, the interaction analyses indicated phenotype-phenotype (OR = 525.7; 95% CI, 60.0 to 4,602.1) and gene-environment (OR = 232.3; 95% CI, 28.7 to 1,876.7) interactions associated with increased risk for livestock-associated S. aureus CC9 carriage. These findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact, raising questions about the potential for occupational exposure to opportunistic S. aureus This study adds to existing knowledge by giving insight into the genotypic and phenotypic markers of LA-MRSA. Our findings suggest that livestock-associated S. aureus and MRSA (CC9, IEC negative, and tetracycline resistant) in humans are associated with occupational livestock contact. Future studies should direct more

Methicillin-Resistant Staphylococcus aureus nosocomial infection trends in Hospital universiti sains Malasia during 2002-2007

International Nuclear Information System (INIS)

Al-Talib, Hasnain I.; Yean, Chan Y

2010-01-01

Methicillin-resistant staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide.The aim of the present study was to assess the burden of MRSA nosocomial infection,its association with factors of interest, and its antimicrobial susceptibility.This was a retrospective analysis of a database of all s aureus that were cultured from patients admitted to the defferent wards of hospital universiti sains malasia(HUSM) over a aperiod of 6 years.The MRSA infections rate was 10.0 Per 1000 hospital admissions.The incidence density rate of MRSA infections during the study period was 1.8 per 1000 patient-days,with annual rates ranging from 0.95 to 3.47 per 1000 patients-days.Duration of hospitalization,previous antibiotic use,and bedside invasive proceures of MRSa infections were found in orthopedic wards (25.3%) followed by surgical wards (18.2%) amd omtensive care units(ICU) (16.4%).All MRSA isolates were resistant to erythromycin (98.0%),co-trimoxazole (94.0%)and gentamicin (92.0%)clindamycin was the best antibiotic with only 6% resistance.All MRSA isolates were sensitive to vancomycin.The rate of the noscomial MRSA infection per 1000 admissions was higher than that in other studies.The three factors associated most signaficantly with acquired MRSA infections included duration of hospitalization,antibiotic use,and bedside invasive procedures.This study confirmed that vancomycin-resistant s aureus has not yet been established in HUSM (Author).

Structural Basis for Linezolid Binding Site Rearrangement in the Staphylococcus aureus Ribosome.

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Belousoff, Matthew J; Eyal, Zohar; Radjainia, Mazdak; Ahmed, Tofayel; Bamert, Rebecca S; Matzov, Donna; Bashan, Anat; Zimmerman, Ella; Mishra, Satabdi; Cameron, David; Elmlund, Hans; Peleg, Anton Y; Bhushan, Shashi; Lithgow, Trevor; Yonath, Ada

2017-05-09

An unorthodox, surprising mechanism of resistance to the antibiotic linezolid was revealed by cryo-electron microscopy (cryo-EM) in the 70S ribosomes from a clinical isolate of Staphylococcus aureus This high-resolution structural information demonstrated that a single amino acid deletion in ribosomal protein uL3 confers linezolid resistance despite being located 24 Å away from the linezolid binding pocket in the peptidyl-transferase center. The mutation induces a cascade of allosteric structural rearrangements of the rRNA that ultimately results in the alteration of the antibiotic binding site. IMPORTANCE The growing burden on human health caused by various antibiotic resistance mutations now includes prevalent Staphylococcus aureus resistance to last-line antimicrobial drugs such as linezolid and daptomycin. Structure-informed drug modification represents a frontier with respect to designing advanced clinical therapies, but success in this strategy requires rapid, facile means to shed light on the structural basis for drug resistance (D. Brown, Nat Rev Drug Discov 14:821-832, 2015, https://doi.org/10.1038/nrd4675). Here, detailed structural information demonstrates that a common mechanism is at play in linezolid resistance and provides a step toward the redesign of oxazolidinone antibiotics, a strategy that could thwart known mechanisms of linezolid resistance. Copyright © 2017 Belousoff et al.

Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

OpenAIRE

Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

2012-01-01

Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

Intracellular activity of the peptide antibiotic NZ2114: studies with Staphylococcus aureus and human THP-1 monocytes, and comparison with daptomycin and vancomycin

DEFF Research Database (Denmark)

Brinch, Karoline Sidelmann; Tulkens, Paul M; Van Bambeke, Francoise

2010-01-01

Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism.......Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism....

The camelliagenin from defatted seeds of Camellia oleifera as antibiotic substitute to treat chicken against infection of Escherichia coli and Staphylococcus aureus.

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Ye, Yong; Yang, Qian; Fang, Fei; Li, Yue

2015-08-18

Escherichia coli and Staphylococcus aureus are the main pathogens infectious to poultry, and their resistances against antibiotics have become troublesome currently. Biofilm formation is an important reason for drug resistance. Our previous research has found that the extract of Camellia oleifera seeds has lots of pharmacological effects. In order to find the substitute for antibiotics, the saponin was isolated from the defatted C. oleifera seeds with structural identification. Its efficacy was evaluated by the inhibition on amoxicillin-resistant E. coli and erythromycin-resistant S. aureus and therapeutic effect on chicks infected by the two bacteria. The bacterial growth inhibition rate increased and the bacterial count in vivo decreased significantly in dose dependence after administration of the saponin and its combination with amoxicillin or erythromycin, suggesting its antibacterial effect. The saponin identified as camelliagenin shows significant inhibition on the biofilm of E. coli and S. aureus, and it is related to the decrease of mannitol dehydrogenase (MDH) activity and extracellular DNA (eDNA) content. Molecular simulation reveals the strong interaction existing between the saponin and MDH or eDNA. The mechanism of camelliagenin's improvement on antibiotic effects is its interaction with MDH and eDNA in biofilm. The saponin is a prospective substitute of antibiotics, and molecular simulation is a convenient alternative method to find out hopeful candidates of antibiotics substitute.

[Antibiotic susceptibility of Staphylococcus aureus and Streptococcus pneumoniae in healthy carrier individuals in primary care in Barcelona area].

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Llor, Carles; Boada, Albert; Pons-Vigués, Mariona; Grenzner, Elisabet; Juvé, Rosa; Almeda, Jesús

2018-01-01

The information available on antibiotic resistance patterns are generally based on specimens from hospitalised individuals. This study was aimed at evaluating the antibiotic resistance rate of nasal carriage strains of Staphylococcus aureus and Streptococcus pneumoniae in healthy individuals, in accordance with age and gender, attended in Primary Care Centres (PCC). Cross-sectional study. Seven PCC in the Barcelona area. Healthy nasal carriers aged 4years or more who did not present with any sign of infectious disease, and had not taken any antibiotic or had been hospitalised in the previous 3months. A total of 3,969 nasal swabs valid for identification were collected between 2010 and 2011 and were sent to one central microbiological laboratory for isolation of both pathogens. Resistance to common antibiotics was determined on the basis of the current European Committee on Antimicrobial Susceptibility Testing guidelines on cut-off points. The prevalence of methicillin-resistant S.aureus was 1.3% (95%CI: 0.5-2.1%), with resistance rates of 87.1% to phenoxymethylpenicillin and 11.6% to azithromycin, with no significant differences with age and gender. A total of 2.4% (95CI%: 0.1-4.7%) of the pneumococcal strains were highly resistant to both phenoxymethylpenicillin and macrolides, whereas the highest resistance rates were to cefaclor (53.3%), followed by tetracycline (20%) and cefuroxime (12.1%). These pathogens have lower resistance rates in the community than in the hospital setting. Primary Care physicians must be more aware of the current antimicrobial resistance, in order to ensure prudent use of antibiotics. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Multidrug efflux pumps in Staphylococcus aureus and their clinical implications.

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Jang, Soojin

2016-01-01

Antibiotic resistance is rapidly spreading among bacteria such as Staphylococcus aureus, an opportunistic bacterial pathogen that causes a variety of diseases in humans. For the last two decades, bacterial multidrug efflux pumps have drawn attention due to their potential association with clinical multidrug resistance. Numerous researchers have demonstrated efflux-mediated resistance in vitro and in vivo and found novel multidrug transporters using advanced genomic information about bacteria. This article aims to provide a concise summary of multidrug efflux pumps and their important clinical implications, focusing on recent findings concerning S. aureus efflux pumps.

In vitro mecA gene transfer among Staphylococcus aureus in ...

African Journals Online (AJOL)

... Staphylococcus aureus, Malaysian clinical isolates, to methicillin-sensitive one. PCR-based method was used in combination with the selective antibiotic screening method to study the transfer of resistance among clinical isolates carrying different genetic markers. After performing the mixed liquid culture experiments, two ...

The Staphylococcus aureus α-Acetolactate Synthase ALS Confers Resistance to Nitrosative Stress

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Sandra M. Carvalho

2017-07-01

Full Text Available Staphylococcus aureus is a worldwide pathogen that colonizes the human nasal cavity and is a major cause of respiratory and cutaneous infections. In the nasal cavity, S. aureus thrives with high concentrations of nitric oxide (NO produced by the innate immune effectors and has available for growth slow-metabolizing free hexoses, such as galactose. Here, we have used deep sequencing transcriptomic analysis (RNA-Seq and 1H-NMR to uncover how S. aureus grown on galactose, a major carbon source present in the nasopharynx, survives the deleterious action of NO. We observed that, like on glucose, S. aureus withstands high concentrations of NO when using galactose. Data indicate that this resistance is, most likely, achieved through a distinct metabolism that relies on the increased production of amino acids, such as glutamate, threonine, and branched-chain amino acids (BCAAs. Moreover, we found that under NO stress the S. aureus α-acetolactate synthase (ALS enzyme, which converts pyruvate into α-acetolactate, plays an important role. ALS is proposed to prevent intracellular acidification, to promote the production of BCAAs and the activation of the TCA cycle. Additionally, ALS is shown to contribute to the successful infection of murine macrophages. Furthermore, ALS contributes to the resistance of S. aureus to beta-lactam antibiotics such as methicillin and oxacillin.

Staphyloxanthin photobleaching sensitizes methicillin-resistant Staphylococcus aureus to reactive oxygen species attack

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Dong, Pu-Ting; Mohammad, Haroon; Hui, Jie; Wang, Xiaoyu; Li, Junjie; Liang, Lijia; Seleem, Mohamed N.; Cheng, Ji-Xin

2018-02-01

Given that the dearth of new antibiotic development loads an existential burden on successful infectious disease therapy, health organizations are calling for alternative approaches to combat methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we report a drug-free photonic approach to eliminate MRSA through photobleaching of staphyloxanthin, an indispensable membrane-bound antioxidant of S. aureus. The photobleaching process, uncovered through a transient absorption imaging study and quantitated by absorption spectroscopy and mass spectrometry, decomposes staphyloxanthin, and sensitizes MRSA to reactive oxygen species attack. Consequently, staphyloxanthin bleaching by low-level blue light eradicates MRSA synergistically with external or internal reactive oxygen species. The effectiveness of this synergistic therapy is validated in MRSA culture, MRSAinfected macrophage cells. Collectively, these findings highlight broad applications of staphyloxanthin photobleaching for treatment of MRSA infections.

Beyond conventional antibiotics for the future treatment of methicillin-resistant Staphylococcus aureus infections: two novel alternatives.

LENUS (Irish Health Repository)

Fitzgerald-Hughes, Deirdre

2012-08-01

The majority of antibiotics currently used to treat methicillin-resistant Staphylococus aureus (MRSA) infections target bacterial cell wall synthesis or protein synthesis. Only daptomycin has a novel mode of action. Reliance on limited targets for MRSA chemotherapy, has contributed to antimicrobial resistance. Two alternative approaches to the treatment of S. aureus infection, particularly those caused by MRSA, that have alternative mechanisms of action and that address the challenge of antimicrobial resistance are cationic host defence peptides and agents that target S. aureus virulence. Cationic host defence peptides have multiple mechanisms of action and are less likely than conventional agents to select resistant mutants. They are amenable to modifications that improve their stability, effectiveness and selectivity. Some cationic defence peptides such as bactenecin, mucroporin and imcroporin have potent in vitro bactericidal activity against MRSA. Antipathogenic agents also have potential to limit the pathogenesis of S aureus. These are generally small molecules that inhibit virulence targets in S. aureus without killing the bacterium and therefore have limited capacity to promote resistance development. Potential antipathogenic targets include the sortase enzyme system, the accessory gene regulator (agr) and the carotenoid biosynthetic pathway. Inhibitors of these targets have been identified and these may have potential for further development.

Experiences of nursing staff caring for patients with methicillin-resistant Staphylococcus aureus.

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Andersson, H; Andreassen Gleissman, S; Lindholm, C; Fossum, B

2016-06-01

Methicillin-resistant Staphylococcus aureus is a resistant variant of S. aureus and can cause pneumonia, septicaemia and, in some cases, death. Caring for patients with antibiotic resistant bacteria is a challenge for healthcare personnel. There is a risk of spreading the bacteria among patients and of healthcare personnel being infected themselves. To describe nursing staffs' experiences of caring for patients with methicillin-resistant S. aureus in Sweden. A descriptive qualitative approach was used and 15 nurses from different hospitals and care units, including emergency and geriatric wards and nursing homes in Stockholm, were interviewed. All nurses had been involved in the care of patients with methicillin-resistant S. aureus, but not on a regular basis. The interviews were analysed using qualitative content analysis. Three themes emerged from the data: feeling ignorant, afraid and insecure, feeling competent and secure and feeling stressed and overworked. The more knowledge the nurses acquired about methicillin-resistant S. aureus, the more positive was their attitude to caring for these patients. Caring for patients with methicillin-resistant S. aureus without adequate knowledge of how to protect oneself and other patients against transmission may provoke anxiety among personnel. Guidelines, memos and adequate information at the right time are of central importance. Healthcare personnel must feel safe in their role as caregivers. All patients have the right to have the same quality of care regardless of the diagnosis and a lack of knowledge influences the level of care given. This study demonstrates the importance of education when caring for patients with infectious diseases. Hopefully, knowledge gained from our study can provide guidance for future health care when new diseases and infections occur. © 2016 International Council of Nurses.

Photodynamic inactivation of antibiotic-resistant pathogens

International Nuclear Information System (INIS)

Paronyan, M.H.

2015-01-01

Nowadays methicillin-resistant strain Staphylococcus aureus (MRSA) is one of the most widespread multiresistant bacteria. Photodynamic inactivation (PDI) of microorganisms by photosensitizers (PS) may be an effective and alternative therapeutic option against antibiotic resistant bacteria. The effectiveness of new PS cationic porphyrin Zn-TBut4PyP was tested on two strains of S. aureus (MRSA and methicillin-sensitive S. aureus). It is shown that Zn-TBut4PyP has high photodynamic activity against both strains

Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

Science.gov (United States)

Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

2015-01-01

Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

Prevalence of community-associated multi-resistant Staphylococcus ...

African Journals Online (AJOL)

Antimicrobial resistance has become a great public health problem worldwide and multi-drugvresistance Staphylococcus aureus has been widely reported. This study determined the pattern of resistance to ten commonly used antibiotics. Urine samples collected from healthy women volunteers in the Abuja were cultured ...

Comparative antibacterial activity of topical antiseptic eardrops against methicillin-resistant Staphylococcus aureus and quinolone-resistant Pseudomonas aeruginosa.

Science.gov (United States)

Youn, Cha Kyung; Jang, Sook-Jin; Jo, Eu-Ri; Choi, Ji Ae; Sim, Ju-Hwan; Cho, Sung Il

2016-06-01

Aural irrigation using antiseptic solutions can be an effective medical treatment of chronic suppurative otitis media (CSOM) owing to the increasing prevalence of antibiotic-resistant CSOM infections. In the present study, we compared the antimicrobial activities of 100% Burow's solution, 50% Burow's solution, 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), quinolone-resistant Pseudomonas aeruginosa (QRPA), and quinolone-susceptible P. aeruginosa (QSPA) in vitro. We examined the antimicrobial activities of five antiseptic solutions against MRSA, MSSA, QRPA, and QSPA. The antimicrobial activities of the solutions were calculated as a percentage of the surviving microorganisms by dividing the viable count in each antiseptic solution with that in control. The time (D10 value) required for each of the five solutions to inactivate 90% of the microorganism population was also investigated. Burow's solution exhibited the highest antimicrobial activity and the lowest D10 value against MRSA, MSSA, QRPA, and QSPA, followed by 2% acetic acid, vinegar with water (1:1), and 4% boric acid solution. Our results indicate that Burow's solution has the most potent activity against bacteria including antibiotic-resistant strains. Twofold dilution of the solution is recommended to avoid ototoxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Unraveling the dynamics of community-associated methicillin-resistant Staphylococcus aureus

NARCIS (Netherlands)

Bootsma, M.C.; Bonten, M.J.M.

2013-01-01

Since the first description of the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strain USA300 [1] in the 1990s, this pathogen has emerged worldwide [2]. Within a decade, USA300 has become the most prevalent cause of community-acquired S. aureus infections in many

Methicillin-resistant Staphylococcus aureus: Prevalence, incidence, risk factors, and effects on survival of patients in a specialist palliative care unit: A prospective observational study.

Science.gov (United States)

Gleeson, Aoife; Larkin, Philip; Walsh, Cathal; O'Sullivan, Niamh

2016-04-01

Little is known about the impact of methicillin-resistant Staphylococcus aureus in palliative care settings. To date, the clinical impact of methicillin-resistant Staphylococcus aureus in palliative care is unknown. To determine prevalence and incidence of methicillin-resistant Staphylococcus aureus colonisation in a specialist palliative care setting, to identify risk factors for methicillin-resistant Staphylococcus aureus colonisation, to determine the eradication success rate and to determine the impact of methicillin-resistant Staphylococcus aureus on survival. Prospective cohort study. Data were collected for consecutive admissions to an inpatient palliative care service. Patients were screened for methicillin-resistant Staphylococcus aureus colonisation on admission and 1 week post admission. Methicillin-resistant Staphylococcus aureus eradication was attempted in methicillin-resistant Staphylococcus aureus positive patients. Data were collected from 609 admissions for 466 individual patients. Admission screening data were available in 95.5%. Prevalence of methicillin-resistant Staphylococcus aureus colonisation was 11.59% (54 patients). One week incidence of methicillin-resistant Staphylococcus aureus colonisation was 1.2%. Risk factors for methicillin-resistant Staphylococcus aureus colonisation were determined using Chi-Squared test and included high Waterlow score (p resistant Staphylococcus aureus status prior to admission (p resistant Staphylococcus aureus was eradicated in 8.1% of admissions, while 46 patients commenced on the protocol (62.2%) died before completing it. Methicillin-resistant Staphylococcus aureus did not significantly impact survival but was significantly associated with having infection episodes and longer length of stay. This study identified risk factors for methicillin-resistant Staphylococcus aureus colonisation in palliative care patients. Methicillin-resistant Staphylococcus aureus was eradicated in 8.1% of patients. Hence

Is the Colonisation of Staphylococcus aureus in Pets Associated with Their Close Contact with Owners?

Directory of Open Access Journals (Sweden)

Karolina Bierowiec

Full Text Available In human beings and animals, staphylococci constitute part of the normal microbial population. Staphylococcus aureus could be classified as an opportunistic pathogen because the bacteria are noted in clinically healthy individuals, but when the immune system becomes compromised, they can also cause a wide range of infections. The objective of this study was to test the hypothesis that cats who are in close contact with their owners are at the greatest risk of being colonised with S. aureus. Two groups of cats were investigated: single, pet (domestic cats that do not have outdoor access; and a local population of feral cats living in urban areas. The prevalence of S. aureus in domestic cats was 19.17%, while it's prevalence in the feral cat population was only 8.3%; which was statistically significant. Analysis of antibiotic resistance, at the genotypic as well as phenotypic level, showed that S. aureus isolates from pet cats were more likely to harbour antibiotic resistant determinants. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA in households was 10.21%, while in feral cats it was only 1.4%. In conclusion, this study has revealed a correlation between close contact with humans and a higher risk of the cats being colonised with S. aureus and harbouring the antibiotic resistant determinants.

Is the Colonisation of Staphylococcus aureus in Pets Associated with Their Close Contact with Owners?

Science.gov (United States)

Bierowiec, Karolina; Płoneczka-Janeczko, Katarzyna; Rypuła, Krzysztof

2016-01-01

In human beings and animals, staphylococci constitute part of the normal microbial population. Staphylococcus aureus could be classified as an opportunistic pathogen because the bacteria are noted in clinically healthy individuals, but when the immune system becomes compromised, they can also cause a wide range of infections. The objective of this study was to test the hypothesis that cats who are in close contact with their owners are at the greatest risk of being colonised with S. aureus. Two groups of cats were investigated: single, pet (domestic) cats that do not have outdoor access; and a local population of feral cats living in urban areas. The prevalence of S. aureus in domestic cats was 19.17%, while it’s prevalence in the feral cat population was only 8.3%; which was statistically significant. Analysis of antibiotic resistance, at the genotypic as well as phenotypic level, showed that S. aureus isolates from pet cats were more likely to harbour antibiotic resistant determinants. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in households was 10.21%, while in feral cats it was only 1.4%. In conclusion, this study has revealed a correlation between close contact with humans and a higher risk of the cats being colonised with S. aureus and harbouring the antibiotic resistant determinants. PMID:27227897

Molecular characteristics of antimicrobial resistance and virulence determinants of Staphylococcus aureus isolates derived from clinical infection and food.

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Luo, Kui; Shao, Fuye; Kamara, Kadijatu N; Chen, Shuaiyin; Zhang, Rongguang; Duan, Guangcai; Yang, Haiyan

2018-04-20

Staphylococcus aureus (S. aureus) is an important human etiologic agent. An investigation of the characteristics of common genotypes of S. aureus relating to pathogenicity and antibiotic resistance may provide a foundation to prevent infection. This study collected 275 S. aureus isolates from Zhengzhou city in China, including 148 isolates from patient samples and 127 isolates from ready-to-eat food samples. Antimicrobial susceptibility testing was performed using the broth dilution method. Molecular characteristics of antimicrobial resistance, virulence, and genotypes were identified by polymerase chain reaction (PCR). In total, 34.18% (94/275) of S. aureus isolates were MRSA. Compared with food isolates, clinical isolates had significantly higher antibiotic resistance rates, carrying resistance genes such as acc(6')/aph(2'), aph(3')-III, ermA, and ermB and virulence genes such as tetM, sea, seb, pvl, and etb. MRSA-t030-agrI-SCCmecIII and MSSA-t002-agrII were the most common strain types among clinical strains, and MRSA-t002-agrII-SCCmecIII and MSSA-t002-agrII were the most common strain types among food strains. Additionally, some strains in the agr group were also spa type-specific, suggesting that there may be phenotypic consistency. Clinical isolates contained higher numbers of resistance genes and demonstrated higher antibiotic resistance, while 2 source strains exhibited high toxicity. These results indicate that bacteria with different origins may have undergone different evolutionary processes. As resistance and virulence factors in food bacteria can be transmitted to humans, food handlers should strictly follow hygienic measures during food production to ensure the safety of human consumers. © 2018 Wiley Periodicals, Inc.

Molecular characterization of a new efficiently transducing bacteriophage identified in meticillin-resistant Staphylococcus aureus.

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Varga, Marian; Pantůček, Roman; Růžičková, Vladislava; Doškař, Jirˇí

2016-01-01

In Staphylococcus aureus, generalized transduction mediated by temperate bacteriophages represents a highly efficient way of transferring antibiotic resistance genes between strains. In the present study, we identified and characterized in detail a new efficiently transducing bacteriophage of the family Siphoviridae, designated ϕJB, which resides as a prophage in the meticillin-resistant S. aureus (MRSA) strain Jevons B. Whole-genome sequencing followed by detailed in silico analysis uncovered a linear dsDNA genome consisting of 43 ,12 bp and comprising 70 ORFs, of which ∼40 encoded proteins with unknown function. A global genome alignment of ϕJB and other efficiently transducing phages ϕ11, ϕ53, ϕ80, ϕ80α and ϕNM4 showed a high degree of homology with ϕNM4 and substantial differences with regard to other phages. Using a model transduction system with a well-defined donor and recipient, ϕJB transferred the tetracycline resistance plasmid pT181 and a penicillinase plasmid with outstanding frequencies, beating most of the above-mentioned phages by an order of magnitude. Moreover, ϕJB demonstrated high frequencies of transferring antibiotic resistance plasmids even upon induction from a lysogenic donor strain. Considering such transducing potential, ϕJB and related bacteriophages may serve as a suitable tool for elucidating the nature of transduction and its contribution to the spread of antibiotic resistance genes in naturally occurring MRSA populations.

Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia.

Science.gov (United States)

Enayet, Iram; Nazeri, Ali; Johnson, Leonard B; Riederer, Kathleen; Pawlak, Joan; Saravolatz, Louis D

2006-04-01

A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

Methicillin-Resistant Staphylococcus aureus (MRSA Detection from the Hands of Jatinangor Community Health Center’s Health Care Providers

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Jeevanisha Patmanathan

2015-06-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus is a bacterium that is resistance towards β-lactam antibiotics, and it seems to be one of the leading causes of nosocomial infections. Hands of the health care workers are said to be the main source for the nosocomial transmission. Thus, the study aims to determine methicillin-resistant S. aureus from the hands of Jatinangor Community Health Center’s health care workers. Methods: Samples were taken from the hands of 30 Jatinangor Community Health Center’s staffs, including medical and paramedical; from October 2012 to November 2012. Then, these samples underwent further laboratory examinations, starting from culture, identification and susceptibility test towards cefoxitin, in identifying methicillin-resistant S. aureus. Results: Out of the 30 samples taken, 6 samples (20% were positive for S. aureus isolates. In which, 4 (13.33% of the samples were positive for methicillin-resistant S. aureus. Conclusions: Since, health care workers are the main people in contact with patients and maintaining proper hand hygiene makes a huge difference; hand hygiene should be given adequate attention for the benefit of all.

Eliminação de resistência a drogas por fluorquinolonas em Staphylococcus aureus de origem bovina Elimination of resistance to drugs by fluoroquinolones in bovine strains of Staphylococcus aureus

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Maria S.V. Pereira

2004-03-01

Full Text Available Cepas de Staphylococcus aureus de origem bovina foram submetidas ao tratamento com quatro fluoquinolonas na concentração subinibitória (1/2 x CMI, para avaliar a influência desses agentes sobre plasmídios. A ciprofloxacina mostrou ser a fluorquinolona mais eficiente, eliminando marcas de resistência para estreptomicina, tetraciclina, penicilina e cádmio. A norfloxacina e a pefloxacina eliminaram resistência para penicilina e tetraciclina, respectivamente; no entanto, não foi evidenciada a eliminação de plasmídio com ofloxacina. Os resultados confirmam a eficácia das fluor-quinolonas em eliminar plasmídios de resistência mostrando a importância desses estudos como contribuição para o entendimento da prevenção de linhagens multiresistentes, uma vez que as quinolonas em concentrações subinibitórias podem aumentar a sensibilidade das linhagens a outros agentes antimicrobianos.Bovine strains of Staphylococcus aureus were submitted to treatment with four fluoro-quinolones in subinhibitory concentrations (1/2 x MICs to evaluate their influence on the curing of plasmids. Ciprofloxacin showed to be the most efficient by eliminating resistance to streptomycin, tetracyclin, penicillin, and cadmium nitrate. Norfloxacin and pefloxacin eliminated penicillin- and tetracyclin-resistance respectively. Otherwise, plasmids elimination by ofloxacin was not evidenced. The results obtained in this study confirm the potential of fluoroquinolones to eliminate antibiotic-resistant plasmids, and showed to be a valuable contribution for the prevention of multi-resistant strains, and may even enhance their sensitivity to other chemotherapeutic agents.

Methicillin-resistant Staphylococcus aureus transmission

DEFF Research Database (Denmark)

Andersen, Leif Percival; Nielsen, Xiaohui

2015-01-01

INTRODUCTION: Even though methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of nosocomial infections, it may often be difficult to evaluate the exact route of transmission. METHODS: In this study, we describe four cases of nosocomial transmission of MRSA in a hospital with a low...... increase the risk of contaminating hands, arms and the front of the uniform. Hand hygiene is therefore essential, but the use of protection gowns with long sleeves is also important in order to prevent transmission of MRSA. After culture of MRSA and implementation of specific precautions to prevent...

rRNA Operon Copy Number Can Explain the Distinct Epidemiology of Hospital-Associated Methicillin-Resistant Staphylococcus aureus

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Jansen, M. D.; Bosch, T.; Jansen, W. T. M.; Schouls, L.; Jonker, M. J.; Boel, C. H. E.

2016-01-01

The distinct epidemiology of original hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and early community-associated MRSA (CA-MRSA) is largely unexplained. S. aureus carries either five or six rRNA operon copies. Evidence is provided for a scenario in which MRSA has adapted to the hospital environment by rRNA operon loss (six to five copies) due to antibiotic pressure. Early CA-MRSA, in contrast, results from wild-type methicillin-susceptible S. aureus (MSSA) that acquired mecA without loss of an rRNA operon. Of the HA-MRSA isolates (n = 77), 67.5% had five rRNA operon copies, compared to 23.2% of the CA-MRSA isolates (n = 69) and 7.7% of MSSA isolates (n = 195) (P operon copies. For all subsets, a correlation between resistance profile and rRNA copy number was found. Furthermore, we showed that in vitro antibiotic pressure may result in rRNA operon copy loss. We also showed that without antibiotic pressure, S. aureus isolates containing six rRNA copies are more fit than isolates with five copies. We conclude that HA-MRSA and cystic fibrosis isolates most likely have adapted to an environment with high antibiotic pressure by the loss of an rRNA operon copy. This loss has facilitated resistance development, which promoted survival in these niches. However, strain fitness decreased, which explains their lack of success in the community. In contrast, CA-MRSA isolates retained six rRNA operon copies, rendering them fitter and thereby able to survive and spread in the community. PMID:27671073

Role of Berberine in the Treatment of Methicillin-Resistant Staphylococcus aureus Infections

Science.gov (United States)

Chu, Ming; Zhang, Ming-Bo; Liu, Yan-Chen; Kang, Jia-Rui; Chu, Zheng-Yun; Yin, Kai-Lin; Ding, Ling-Yu; Ding, Ran; Xiao, Rong-Xin; Yin, Yi-Nan; Liu, Xiao-Yan; Wang, Yue-Dan

2016-04-01

Berberine is an isoquinoline alkaloid widely used in the treatment of microbial infections. Recent studies have shown that berberine can enhance the inhibitory efficacy of antibiotics against clinical multi-drug resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA). However, the underlying mechanisms are poorly understood. Here, we demonstrated that sub-minimum inhibitory concentrations (MICs) of berberine exhibited no bactericidal activity against MRSA, but affected MRSA biofilm development in a dose dependent manner within the concentration ranging from 1 to 64 μg/mL. Further study indicated that berberine inhibited MRSA amyloid fibrils formation, which consist of phenol-soluble modulins (PSMs). Molecular dynamics simulation revealed that berberine could bind with the phenyl ring of Phe19 in PSMα2 through hydrophobic interaction. Collectively, berberine can inhibit MRSA biofilm formation via affecting PSMs’ aggregation into amyloid fibrils, and thereby enhance bactericidal activity of antibiotics. These findings will provide new insights into the multiple pharmacological properties of berberine in the treatment of microbial-generated amyloid involved diseases.

Occurrence of Methicilin-resistant Staphylococcus aureus in a ...

African Journals Online (AJOL)

VO Ogunleye, AO Ogunleye, ATP Ajuwape, KA Akande, AI Adetosoye ... Taking into consideration the danger associated with methicillin resistant Staphylococcus aureus, the findings from this study underscores the need for public enlightenment of both the hospital workers and the general public on the risk associated with ...

Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

Science.gov (United States)

Domínguez, M A; Liñares, J; Martín, R

1997-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy

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Cin Kong

2016-03-01

Full Text Available Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins.

Having your cake and eating it - Staphylococcus aureus small colony variants can evolve faster growth rate without losing their antibiotic resistance

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Gerrit Brandis

2017-08-01

Full Text Available Staphylococcus aureus can produce small colony variants (SCVs during infections. These cause significant clinical problems because they are difficult to detect in standard microbiological screening and are associated with persistent infections. The major causes of the SCV phenotype are mutations that inhibit respiration by inactivation of genes of the menadione or hemin biosynthesis pathways. This reduces the production of ATP required to support fast growth. Importantly, it also decreases cross-membrane potential in SCVs, resulting in decreased uptake of cationic compounds, with reduced susceptibility to aminoglycoside antibiotics as a consequence. Because SCVs are slow-growing (mutations in men genes are associated with growth rates in rich medium ~30% of the wild-type growth rate bacterial cultures are very susceptible to rapid takeover by faster-growing mutants (revertants or suppressors. In the case of reversion, the resulting fast growth is obviously associated with the loss of antibiotic resistance. However, direct reversion is relatively rare due to the very small genetic target size for such mutations. We explored the phenotypic consequences of SCVs evolving faster growth by routes other than direct reversion, and in particular whether any of those routes allowed for the maintenance of antibiotic resistance. In a recent paper (mBio 8: e00358-17 we demonstrated the existence of several different routes of SCV evolution to faster growth, one of which maintained the antibiotic resistance phenotype. This discovery suggests that SCVs might be more adaptable and problematic that previously thought. They are capable of surviving as a slow-growing persistent form, before evolving into a significantly faster-growing form without sacrificing their antibiotic resistance phenotype.

Methicillin-resistant Staphylococcus aureus in Pig Farming

OpenAIRE

Voss, Andreas; Loeffen, Frans; Bakker, Judith; Klaassen, Corne; Wulf, Mireille

2005-01-01

We conducted a study among a group of 26 regional pig farmers to determine the methicillin-resistant Staphylococcus aureus prevalence rate and found it was >760 times greater than the rate of patients admitted to Dutch hospitals. While spa-type t108 is apparently a more widespread clone among pig farmers and their environment, we did find other spa-types.

Methicilin-resistant Staphylococcus aureus (MRSA) at Jos University ...

African Journals Online (AJOL)

A prospective surveillance of Methicillin resistant staphylococcus aureus (MRSA) was carried out at Jos University Teaching Hospital, Nigeria, over a one year period. This study highlights the continuos importance of MRSA in causing both hospital and to a less extent community acquired infections. Out of the 180 ...

METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS IN LAB COATS OF NURSING STUDENTS

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Jean Phellipe Marques do Nascimento

2016-05-01

Full Text Available The aim of the present study was to investigate the presence of Staphylococcus sp. in lab coats nursing students, in addition to determining the antimicrobial sensitivity profile of the isolated bacteria. The bacterial samples were collected, identified and characterized phenotypically, with subsequent determination of antimicrobial sensitivity profile by disk diffusion technique, according to recommendation of the Clinical and Laboratory Standards Institute. 57 colonies were isolated, where 51% were identified as Staphylococcus coagulase negative, 47% as Staphylococcus aureus and 2% belonging to a genus not identified. Among the samples identified as S. aureus, 15% were resistant to Oxacillin and 55% showed resistance to more than one antimicrobial.The results obtained in this work strengthen the role of the lab coat as a source of contamination of pathogenic microorganisms, as well as its possible role in the spread of these pathogens within and outside the hospital environment

Antibiotic exposure and other risk factors for antimicrobial resistance in nasal commensal staphylococcus aureus: an ecological study in 8 European countries.

NARCIS (Netherlands)

Bijnen, E.M.E. van; Paget, W.J.; Lange-de Klerk, E.S.M. de; Heijer, C.D.J. den; Versporten, A.; Stobberingh, E.E.; Goossen, H.; Schellevis, F.G.

2015-01-01

Objectives: Antimicrobial resistance (AMR) has become a global public health concern which threatens the effective treatment of bacterial infections. Resistant Staphylococcus aureus (including MRSA) increasingly appears in individuals with no healthcare associated risks. Our study assessed risk

Sensitization of Staphylococcus aureus to methicillin and other antibiotics in vitro and in vivo in the presence of HAMLET.

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Laura R Marks

Full Text Available HAMLET (human alpha-lactalbumin made lethal to tumor cells is a protein-lipid complex from human milk with both tumoricidal and bactericidal activities. HAMLET exerts a rather specific bactericidal activity against some respiratory pathogens, with highest activity against Streptococcus pneumoniae, but lacks activity against most other bacterial pathogens, including Staphylococci. Still, ion transport associated with death in S. pneumoniae is also detected to a lower degree in insensitive organisms. In this study we demonstrate that HAMLET acts as an antimicrobial adjuvant that can increase the activity of a broad spectrum of antibiotics (methicillin, vancomycin, gentamicin and erythromycin against multi-drug resistant Staphylococcus aureus, to a degree where they become sensitive to those same antibiotics, both in antimicrobial assays against planktonic and biofilm bacteria and in an in vivo model of nasopharyngeal colonization. We show that HAMLET exerts these effects specifically by dissipating the proton gradient and inducing a sodium-dependent calcium influx that partially depolarizes the plasma membrane, the same mechanism induced during pneumococcal death. These effects results in an increased cell associated binding and/or uptake of penicillin, gentamicin and vancomycin, especially in resistant stains. Finally, HAMLET inhibits the increased resistance of methicillin seen under antibiotic pressure and the bacteria do not become resistant to the adjuvant, which is a major advantageous feature of the molecule. These results highlight HAMLET as a novel antimicrobial adjuvant with the potential to increase the clinical usefulness of antibiotics against drug resistant strains of S. aureus.

Sensitization of Staphylococcus aureus to methicillin and other antibiotics in vitro and in vivo in the presence of HAMLET.

Science.gov (United States)

Marks, Laura R; Clementi, Emily A; Hakansson, Anders P

2013-01-01

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a protein-lipid complex from human milk with both tumoricidal and bactericidal activities. HAMLET exerts a rather specific bactericidal activity against some respiratory pathogens, with highest activity against Streptococcus pneumoniae, but lacks activity against most other bacterial pathogens, including Staphylococci. Still, ion transport associated with death in S. pneumoniae is also detected to a lower degree in insensitive organisms. In this study we demonstrate that HAMLET acts as an antimicrobial adjuvant that can increase the activity of a broad spectrum of antibiotics (methicillin, vancomycin, gentamicin and erythromycin) against multi-drug resistant Staphylococcus aureus, to a degree where they become sensitive to those same antibiotics, both in antimicrobial assays against planktonic and biofilm bacteria and in an in vivo model of nasopharyngeal colonization. We show that HAMLET exerts these effects specifically by dissipating the proton gradient and inducing a sodium-dependent calcium influx that partially depolarizes the plasma membrane, the same mechanism induced during pneumococcal death. These effects results in an increased cell associated binding and/or uptake of penicillin, gentamicin and vancomycin, especially in resistant stains. Finally, HAMLET inhibits the increased resistance of methicillin seen under antibiotic pressure and the bacteria do not become resistant to the adjuvant, which is a major advantageous feature of the molecule. These results highlight HAMLET as a novel antimicrobial adjuvant with the potential to increase the clinical usefulness of antibiotics against drug resistant strains of S. aureus.

Efficacy of antibiotic treatment of implant-associated Staphylococcus aureus infections with moxifloxacin, flucloxacillin, rifampin, and combination therapy: an animal study.

Science.gov (United States)

Greimel, Felix; Scheuerer, Christine; Gessner, Andre; Simon, Michaela; Kalteis, Thomas; Grifka, Joachim; Benditz, Achim; Springorum, Hans-Robert; Schaumburger, Jens

2017-01-01

The efficacy of antibiotic monotherapy and combination therapy in the treatment of implant-associated infection by Staphylococcus aureus was evaluated in an animal study. The femoral medullary cavity of 66 male Wistar rats was contaminated with S. aureus (ATCC 29213) and a metal device was implanted, of which 61 could be evaluated. Six treatment groups were studied: flucloxacillin, flucloxacillin in combination with rifampin, moxifloxacin, moxifloxacin in combination with rifampin, rifampin, and a control group with aqua. The treatment was applied for 14 days. After euthanasia, the bacterial counts in the periprosthetic bone, the soft tissue, and the implant-associated biofilm were measured. Both antibiotic combination treatments (moxifloxacin plus rifampin and flucloxacillin plus rifampin) achieved a highly significant decrease in microbial counts in the bone and soft tissue and in the biofilm. Mono-antibiotic treatments with either moxifloxacin or flucloxacillin were unable to achieve a significant decrease in microbial counts in bone and soft tissue or the biofilm, whilst rifampin was able to reduce the counts significantly only in the biofilm. Antibiotic resistance was measured in 1/3 of the cases in the rifampin group, whereas no resistance was measured in all other groups. The results show that combinations of both moxifloxacin and flucloxacillin plus rifampin are adequate for the treatment of periprosthetic infections due to infections with S. aureus , whereas monotherapies are not effective or not applicable due to the rapid development of antibiotic resistance. Therefore, moxifloxacin is an effective alternative in combination with rifampin for the treatment of implant-associated infections.

Combinations of maggot excretions/secretions and antibiotics are effective against Staphylococcus aureus biofilms and the bacteria derived therefrom

DEFF Research Database (Denmark)

van der Plas, Mariena J A; Dambrot, Cheryl; Dogterom-Ballering, Heleen C M

2010-01-01

OBJECTIVES: Maggots of the blowfly Lucilia sericata are used for the treatment of chronic wounds. Previously we reported that maggot excretions/secretions (ES) break down Staphylococcus aureus biofilms but do not kill the bacteria. As many antibiotics are not effective against biofilms we assessed...... the effect of combinations of ES and antibiotics on S. aureus biofilms and on the survival of the bacteria released from the biofilms. METHODS: Effects of ES, antibiotics (vancomycin, daptomycin or clindamycin) and combinations thereof on S. aureus ATCC 29 213 biofilms and bacterial viability were determined...... using microtitre plates and in vitro killing assays. RESULTS: Vancomycin and daptomycin dose-dependently enhanced biofilm formation, whereas clindamycin reduced S. aureus biofilm size. Adding ES to antibiotic incubations caused a complete biofilm breakdown. After a lag time the bacteria derived from...

Vancomycin-resistant Staphylococcus aureus (VRSA) in hepatic cirrhosis patient: a case report

Science.gov (United States)

Ramazoni, M.; Siregar, M. L.; Jamil, K. F.

2018-03-01

The irrational use of vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) infections result in the emergence of vancomycin-resistant Staphylococcus aureus (VRSA) pathogen, which can pose a threat to the world healthcare. A 32-year-old male with hepatic cirrhosis patient admitted with recurrent gastrointestinal bleeding with a wound in his left leg since 6 months ago; the result microbiological culture showed a VRSA with minimum inhibitory concentration (MIC) vancomycin ≥32μg/mL The patient was treated with trimethoprim/sulfamethoxazole combination according to cultural sensitivity. The second microbiological culture showed thesame result. VRSA is a rare and difficult condition to handle. The success of therapy for this VRSA case warn us how important to cut the S. aureus distribution chain with a high level of resistance.

Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus

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Susanne Blomqvist

2015-04-01

Full Text Available Objective: The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers. Materials and methods: A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins and sea, seb, sec, tst, eta, etb, pvl (toxins. MIC90 and MIC50 were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin. Results: While the hemolytic phenotype was significantly (p<0.001 more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL genotype was found in 73–100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIV-positives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillin-resistant S. aureus (MRSA strains were identified, two from oral infections and one from a Thai HIV patient. Conclusions: S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral

Response of Methicillin-Resistant Staphylococcus aureus to Amicoumacin A

OpenAIRE

Lama, Amrita; Pané-Farré, Jan; Chon, Tai; Wiersma, Anna M.; Sit, Clarissa S.; Vederas, John C.; Hecker, Michael; Nakano, Michiko M.

2012-01-01

Amicoumacin A exhibits strong antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), hence we sought to uncover its mechanism of action. Genome-wide transcriptome analysis of S. aureus COL in response to amicoumacin A showed alteration in transcription of genes specifying several cellular processes including cell envelope turnover, cross-membrane transport, virulence, metabolism, and general stress response. The most highly induced gene was lrgA, encoding an antiho...

Typing of Staphylococcus aureus in order to determine the spread of drug resistant strains inside and outside hospital environment.

Science.gov (United States)

Pobiega, Monika; Wójkowska-Mach, Jadwiga; Heczko, Piotr B

2013-01-01

Staphylococcus aureus is one of the most important etiological factors of both nosocomial and community-acquired infections. Multidrug-resistant S. aureus is frequently isolated nowadays. Antibiotics used on the hospital ward exert a selective pressure on the strains and favor resistant strains. Multidrug-resistant and highly virulent strains can spread not only within the hospital but also between hospitals. Numerous studies show a predominance of one clone on a specific territory. The spread of such dangerous clones to neighboring countries and the entire continent is possible. Typing methods are very useful in infection control and prevention. Modern methods which are based on sequencing are necessary in rationalizing of infection control programs. Typing of Staphylococcus aureus includes methods that allow to determine the spread of drug-resistant pathogens. 'Gold standard' is pulsed-field gel electrophoresis (PFGE), which relies on separating the DNA fragments after restriction cutting. MLST (Multi Locus Sequence Typing) is based on a comparison of"housekeeping" gene sequences controlling the basic cell functions. With the MLST method, it is possible to demonstrate a broad, international spread of the specific clones. However, for epidemiological investigations, MLST seems to be too time-consuming and expensive to be used as a basic typing tool. The complementary method is spa typing, based on the sequencing of short repetitive sequences of the polymorphic X region from the gene encoding protein A. This method can be used for studying molecular evolution of S. aureus, as well as for testing for hospital outbreaks. It is faster and cheaper than MLST. It is also necessary to subtype the elements responsible for methycillin resistance (SCCmec), which allows to distinguish MRSA (Methicillin-resistant Staphylococcus aureus) clones with a common ancestor, but different epidemiological origin. All of those methods have their specific advantages and disadvantages and

Emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different animal species

NARCIS (Netherlands)

Cuny, Christiane; Friedrich, Alexander; Kozytska, Svetlana; Layer, Franziska; Nübel, Ulrich; Ohlsen, Knut; Strommenger, Birgit; Walther, Birgit; Wieler, Lothar; Witte, Wolfgang

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in animals such as horses, pet animals and productive livestock has raised questions of a probable human origin and in more general of host specificity of S. aureus. Particular clonal lineages are obviously specific for humans (e.g.

Antibiotic-Impregnated Central Venous Catheters Do Not Change Antibiotic Resistance Patterns.

Science.gov (United States)

Turnbull, Isaiah R; Buckman, Sara A; Horn, Christopher B; Bochicchio, Grant V; Mazuski, John E

2018-01-01

Antibiotic-impregnated central venous catheters (CVCs) decrease the incidence of infection in high-risk patients. However, use of these catheters carries the hypothetical risk of inducing antibiotic resistance. We hypothesized that routine use of minocycline and rifampin-impregnated catheters (MR-CVC) in a single intensive care unit (ICU) would change the resistance profile for Staphylococcus aureus. We reviewed antibiotic susceptibilities of S. aureus isolates obtained from blood cultures in a large urban teaching hospital from 2002-2015. Resistance patterns were compared before and after implementation of MR-CVC use in the surgical ICU (SICU) in August 2006. We also compared resistance patterns of S. aureus obtained in other ICUs and in non-ICU patients, in whom MR-CVCs were not used. Data for rifampin, oxacillin, and clindamycin were available for 9,703 cultures; tetracycline resistance data were available for 4,627 cultures. After implementation of MR-CVC use in the SICU, rifampin resistance remained unchanged, with rates the same as in other ICU and non-ICU populations (3%). After six years of use of MR-CVCs in the SICU, the rate of tetracycline resistance was unchanged in all facilities (1%-3%). The use of MR-CVCs was not associated with any change in S. aureus oxacillin-resistance rates in the SICU (66% vs. 60%). However, there was a significant decrease in S. aureus clindamycin resistance (59% vs. 34%; p resistance of S. aureus isolates to rifampin or tetracyclines.

Antibiotic resistance and pathogenicity factors in Staphylococcus ...

Indian Academy of Sciences (India)

know which endemic strains of S. aureus in dairy cattle ... Antibiotic resistance; cattle; mastitis; MRSA; pathogenic genes ... recommended by Clinical and Laboratory Standards Institute ...... fnbA, eno, hla and nuc, did not show any relation to.

Alterations in the transcriptome and antibiotic susceptibility of Staphylococcus aureus grown in the presence of diclofenac

Science.gov (United States)

2011-01-01

Background Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) which has been shown to increase the susceptibility of various bacteria to antimicrobials and demonstrated to have broad antimicrobial activity. This study describes transcriptome alterations in S. aureus strain COL grown with diclofenac and characterizes the effects of this NSAID on antibiotic susceptibility in laboratory, clinical and diclofenac reduced-susceptibility (DcRS) S. aureus strains. Methods Transcriptional alterations in response to growth with diclofenac were measured using S. aureus gene expression microarrays and quantitative real-time PCR. Antimicrobial susceptibility was determined by agar diffusion MICs and gradient plate analysis. Ciprofloxacin accumulation was measured by fluorescence spectrophotometry. Results Growth of S. aureus strain COL with 80 μg/ml (0.2 × MIC) of diclofenac resulted in the significant alteration by ≥2-fold of 458 genes. These represented genes encoding proteins for transport and binding, protein and DNA synthesis, and the cell envelope. Notable alterations included the strong down-regulation of antimicrobial efflux pumps including mepRAB and a putative emrAB/qacA-family pump. Diclofenac up-regulated sigB (σB), encoding an alternative sigma factor which has been shown to be important for antimicrobial resistance. Staphylococcus aureus microarray metadatabase (SAMMD) analysis further revealed that 46% of genes differentially-expressed with diclofenac are also σB-regulated. Diclofenac altered S. aureus susceptibility to multiple antibiotics in a strain-dependent manner. Susceptibility increased for ciprofloxacin, ofloxacin and norfloxacin, decreased for oxacillin and vancomycin, and did not change for tetracycline or chloramphenicol. Mutation to DcRS did not affect susceptibility to the above antibiotics. Reduced ciprofloxacin MICs with diclofenac in strain BB255, were not associated with increased drug accumulation. Conclusions The results of

Antimicrobial activity and synergy of antibiotics with two biphenyl compounds, protosappanins A and B from Sappan Lignum against methicillin-resistant Staphylococcus aureus strains.

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Zuo, Guo-Ying; Han, Zong-Qi; Han, Jun; Hao, Xiao-Yan; Tang, Hua-Shu; Wang, Gen-Chun

2015-10-01

This study aims to investigate antimicrobial ingredients from Sappan Lignum and to evaluate their synergy on methicillin-resistant Staphylococcus aureus strains with antibiotics. Bioactivity-guided phytochemical procedures were used to screen the active compounds. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were assayed by broth microdilution. The synergy was evaluated through checkerboard microdilution and loss of viability assays. Protosappanins A (PsA) and B (PsB) were identified from Sappan Lignum extracts. They showed active against both S. aureus and MRSA with MIC or MIC50 at 64 (PsA) and 128 (PsB) mg/L alone. When they were used in combination with antibiotics, they showed best synergy with amikacin and gentamicin with MIC50 (mg/L) of amikacin reduced more significantly from 32 to four (with PsA) and eight (with PsB), and the fractional inhibitory concentration index (FICI) ranged between 0.078 and 0.500 (FICI50  = 0.375). Moreover, the resistance of MRSA towards amikacin and gentamicin could be reversed by the Clinical and Laboratory Standards Institute criteria. The combined bactericidal mode could as well be synergy. PsA and PsB showed very low cytotoxicity in comparison with their promising activity against MRSA. Protosappanins A and B showed both alone activities and resistance reversal effects of amikacin and gentamicin against MRSA, which warrant further investigations for potential combinatory therapy of MRSA infection. © 2015 Royal Pharmaceutical Society.

Effectiveness of simple control measures on methicillin-resistant Staphylococcus aureus infection status and characteristics with susceptibility patterns in a teaching hospital in Peshawar.

Science.gov (United States)

Rafiq, Muhammad Salman; Rafiq, Muhammad Imran; Khan, Taimur; Rafiq, Maria; Khan, Mah Muneer

2015-09-01

To determine the effectiveness of simple control measures on the infection status and characteristics of methicillin-resistant Staphylococcus aureus including susceptibility patterns among health professionals and patients in a teaching hospital. The cross-sectional study was conducted from September 2013 to January 2014, and comprised samples collected from healthcare personnel and patients in the various units of Khyber Teaching Hospital, Peshawar. The specimens were collected before and one month after the implementation of simple control measures for outbreak prevention of methicillin-resistant Staphylococcus aureus. These were tested for culture and antimicrobial susceptibility. Data about methicillin-sensitive and methicillin-resistant Staphylococcus aureus infection, wound characteristics and susceptibility patterns was collected and effectiveness of simple control measures was determined. SPSS 20 was used for statistical analysis. Of the total 390 isolates, 180(46.2%) were Staphylococcus aureus; 77(19.7%) from healthcare personnel and 103(26.4%) from patients. Of these, 164(42.1%) were methicillin-sensitive and 16(4.1%) were methicillin-resistant. Among the patients, 38(15.1%) methicillin-sensitive and 8(3.2%) methicillin-resistant isolates were recovered from wounds or skin and soft tissues. Pus with 33(13.1%) and 4(1.6%) cases respectively was the second most common source. Among methicillin-resistant isolates, resistance to Linezolid was 0%, all were resistant to Oxacillin, Cefoxitin, Amoxicillin, Cefotaxime and Cephradine, and resistance to both Co-Amoxiclav and Ciprofloxacin was 87.5%. After one month of implementation of simple control measures, the number of methicillin-resistant cases among healthcare professionals and patients dropped from 4(2.9%) and 7(10.8%) to 1(0.7%) and 5(2.7%), respectively. Methicillin-resistant and methicillin-sensitive Staphylococcus aureus differed in their anti-microbial susceptibility profiles. Selection of antibiotics

Antibiotic susceptibility pattern and the prevalence of Staphylococcus aureus isolated from skin and soft tissue in Tehran Razi skin hospital (2014-15

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Zeynab Fagheei-Aghmiyuni

2017-06-01

Full Text Available Background: Staphylococcus aureus (S. aureus is the most common cause of skin and soft tissue infections. This study aimed to determine the prevalence of S. aureus isolated from skin and soft tissue and antibiotic susceptibility pattern among the patient hospitalized in Razi skin hospital (Tehran-Iran. Materials and Methods: This cross-sectional study was conducted on patients (n=400 with skin and soft tissue infections in Razi skin hospital. Sterilized swabs were used to collect the skin infection samples. S. aureus isolates were confirmed using biochemical tests (gram staining, catalase, coagulase, DNase test and manitol fermentation tests. Result: 51.3 %( 205 out of 400 of isolates were S. aureus. Ninety six (46.8% of isolates were methicillin and penicillin-resistant S. aureus. All of the isolates showed sensitivity to vancomycin, linezolid. 98% of the isolates were susceptible to daptomycin. One-hundred sixteen (56.6% isolates were multi- drug resistant. Conclusion: More than half of the skin and soft tissue infections were caused by S.aureus. More than 46 percent of the isolates were methicillin resistant. The highest resistance to penicillin was observed.

Selective inhibition of Biotin Protein Ligase from Staphylococcus aureus*

Science.gov (United States)

Soares da Costa, Tatiana P.; Tieu, William; Yap, Min Y.; Pendini, Nicole R.; Polyak, Steven W.; Sejer Pedersen, Daniel; Morona, Renato; Turnidge, John D.; Wallace, John C.; Wilce, Matthew C. J.; Booker, Grant W.; Abell, Andrew D.

2012-01-01

There is a well documented need to replenish the antibiotic pipeline with new agents to combat the rise of drug resistant bacteria. One strategy to combat resistance is to discover new chemical classes immune to current resistance mechanisms that inhibit essential metabolic enzymes. Many of the obvious drug targets that have no homologous isozyme in the human host have now been investigated. Bacterial drug targets that have a closely related human homologue represent a new frontier in antibiotic discovery. However, to avoid potential toxicity to the host, these inhibitors must have very high selectivity for the bacterial enzyme over the human homolog. We have demonstrated that the essential enzyme biotin protein ligase (BPL) from the clinically important pathogen Staphylococcus aureus could be selectively inhibited. Linking biotin to adenosine via a 1,2,3 triazole yielded the first BPL inhibitor selective for S. aureus BPL over the human equivalent. The synthesis of new biotin 1,2,3-triazole analogues using click chemistry yielded our most potent structure (Ki 90 nm) with a >1100-fold selectivity for the S. aureus BPL over the human homologue. X-ray crystallography confirmed the mechanism of inhibitor binding. Importantly, the inhibitor showed cytotoxicity against S. aureus but not cultured mammalian cells. The biotin 1,2,3-triazole provides a novel pharmacophore for future medicinal chemistry programs to develop this new antibiotic class. PMID:22437830

Selective inhibition of biotin protein ligase from Staphylococcus aureus.

Science.gov (United States)

Soares da Costa, Tatiana P; Tieu, William; Yap, Min Y; Pendini, Nicole R; Polyak, Steven W; Sejer Pedersen, Daniel; Morona, Renato; Turnidge, John D; Wallace, John C; Wilce, Matthew C J; Booker, Grant W; Abell, Andrew D

2012-05-18

There is a well documented need to replenish the antibiotic pipeline with new agents to combat the rise of drug resistant bacteria. One strategy to combat resistance is to discover new chemical classes immune to current resistance mechanisms that inhibit essential metabolic enzymes. Many of the obvious drug targets that have no homologous isozyme in the human host have now been investigated. Bacterial drug targets that have a closely related human homologue represent a new frontier in antibiotic discovery. However, to avoid potential toxicity to the host, these inhibitors must have very high selectivity for the bacterial enzyme over the human homolog. We have demonstrated that the essential enzyme biotin protein ligase (BPL) from the clinically important pathogen Staphylococcus aureus could be selectively inhibited. Linking biotin to adenosine via a 1,2,3 triazole yielded the first BPL inhibitor selective for S. aureus BPL over the human equivalent. The synthesis of new biotin 1,2,3-triazole analogues using click chemistry yielded our most potent structure (K(i) 90 nM) with a >1100-fold selectivity for the S. aureus BPL over the human homologue. X-ray crystallography confirmed the mechanism of inhibitor binding. Importantly, the inhibitor showed cytotoxicity against S. aureus but not cultured mammalian cells. The biotin 1,2,3-triazole provides a novel pharmacophore for future medicinal chemistry programs to develop this new antibiotic class.

Antimicrobial resistant coagulase positive Staphylococcus aureus ...

African Journals Online (AJOL)

ADEYEYE

S. aureus is associated with many clinical syndromes including tenosynovitis, omphalitis, femoral head necrosis, .... Markey, 2008) where occurrence of multidrug ... Staphylococcus aureus isolates from bovine mastitis in. Denmark. Veterinary.

Antibiofilm activity of Vetiveria zizanioides root extract against methicillin-resistant Staphylococcus aureus.

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Kannappan, Arunachalam; Gowrishankar, Shanmugaraj; Srinivasan, Ramanathan; Pandian, Shunmugiah Karutha; Ravi, Arumugam Veera

2017-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading human pathogen responsible for causing chronic clinical manifestation worldwide. In addition to antibiotic resistance genes viz. mecA and vanA, biofilm formation plays a prominent role in the pathogenicity of S. aureus by enhancing its resistance to existing antibiotics. Considering the role of folk medicinal plants in the betterment of human health from the waves of multidrug resistant bacterial infections, the present study was intended to explore the effect of Vetiveria zizanioides root on the biofilm formation of MRSA and its clinical counterparts. V. zizanioides root extract (VREX) showed a concentration-dependent reduction in biofilm formation without hampering the cellular viability of the tested strains. Micrographs of scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) portrayed the devastating impact of VREX on biofilm formation. In addition to antibiofilm activity, VREX suppresses the production of biofilm related phenotypes such as exopolysaccharide, slime and α-hemolysin toxin. Furthermore, variation in FT-IR spectra evidenced the difference in cellular factors of untreated and VREX treated samples. Result of mature biofilm disruption assay and down regulation of genes like fnbA, fnbB, clfA suggested that VREX targets these adhesin genes responsible for initial adherence. GC-MS analysis revealed the presence of sesquiterpenes as a major constituent in VREX. Thus, the data of present study strengthen the ethnobotanical value of V. zizanioides and concludes that VREX contain bioactive molecules that have beneficial effect over the biofilm formation of MRSA and its clinical isolates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antibiotic tolerance and the alternative lifestyles of Staphylococcus aureus.

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Bui, Long M G; Conlon, Brian P; Kidd, Stephen P

2017-02-28

Staphylococcus aureus has an incredible ability to survive, either by adapting to environmental conditions or defending against exogenous stress. Although there are certainly important genetic traits, in part this ability is provided by the breadth of modes of growth S. aureus can adopt. It has been proposed that while within their host, S. aureus survives host-generated and therapeutic antimicrobial stress via alternative lifestyles: a persister sub-population, through biofilm growth on host tissue or by growing as small colony variants (SCVs). Key to an understanding of chronic and relapsing S. aureus infections is determining the molecular basis for its switch to these quasi-dormant lifestyles. In a multicellular biofilm, the metabolically quiescent bacterial community additionally produces a highly protective extracellular polymeric substance (EPS). Furthermore, there are bacteria within a biofilm community that have an altered physiology potentially equivalent to persister cells. Recent studies have directly linked the cellular ATP production by persister cells as their key feature and the basis for their tolerance of a range of antibiotics. In clinical settings, SCVs of S. aureus have been observed for many years; when cultured, these cells form non-pigmented colonies and are approximately ten times smaller than their counterparts. Various genotypic factors have been identified in attempts to characterize S. aureus SCVs and different environmental stresses have been implicated as important inducers. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

In vitro biofilm formation by methicillin susceptible and resistant Staphylococcus aureus strains isolated from cystic fibrosis patients

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Antonietta Lambiase

2008-12-01

Full Text Available Staphylococcus aureus is one of the most common pathogens isolated from respiratory tracts of Cystic Fibrosis patients (CF. The infection by this pathogen starts in early infancy, often preceding chronic infections by Pseudomonas aeruginosa. The infection and colonization by methicillin-resistant Staphylococcus aureus (MRSA are, by then, events very frequent among CF patients and this bacterial isolation leads to complications in therapeutic management because of the limited treatment options. Strains of Staphylococcus aureus are able to produce biofilms on natural or synthetic surfaces. Biofilms are sophisticated communities of matrix-encased bacteria and infections by biofilm-producing bacteria are particularly problematic because sessile bacteria can often withstand host immune responses and are generally much more tolerant to antibiotics. The first aim of this work is to evaluate the ability of MRSA strains isolated from respiratory secretions of CF patients to develop biofilms in comparison with methicillin-sensitive Staphylococcus aureus (MSSA strains obtained from respiratory secretions of CF patients.Therefore, our second aim is to evaluate the environmental influence on this ability. To evaluate the development of biofilm on solid matrix and the possible environmental influence,we applied the method described by Christensen et al. We found that a significantly higher number of MRSA strains were biofilm positive compared with MSSA strains (p<0.05.The presence of glucose did not influence the ability to form biofilm in our MRSA strains (p=0.165. MSSA strains are not strong biofilm-producers, but, when grown in TSB added with 0.25% glucose, the number of biofilm-forming strains increases, as expected. These data suggest a possible association between methicillin-resistance and biofilm formation.

Staphylococcus aureus nasal carriage in Ukraine: antibacterial resistance and virulence factor encoding genes.

Science.gov (United States)

Netsvyetayeva, Irina; Fraczek, Mariusz; Piskorska, Katarzyna; Golas, Marlena; Sikora, Magdalena; Mlynarczyk, Andrzej; Swoboda-Kopec, Ewa; Marusza, Wojciech; Palmieri, Beniamino; Iannitti, Tommaso

2014-03-05

The number of studies regarding the incidence of multidrug resistant strains and distribution of genes encoding virulence factors, which have colonized the post-Soviet states, is considerably limited. The aim of the study was (1) to assess the Staphylococcus (S.) aureus nasal carriage rate, including Methicillin Resistant S. aureus (MRSA) strains in adult Ukrainian population, (2) to determine antibiotic resistant pattern and (3) the occurrence of Panton Valentine Leukocidine (PVL)-, Fibronectin-Binding Protein A (FnBPA)- and Exfoliative Toxin (ET)-encoding genes. Nasal samples for S. aureus culture were obtained from 245 adults. The susceptibility pattern for several classes of antibiotics was determined by disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The virulence factor encoding genes, mecA, lukS-lukF, eta, etb, etd, fnbA, were detected by Polymerase Chain Reaction (PCR). The S. aureus nasal carriage rate was 40%. The prevalence of nasal MRSA carriage in adults was 3.7%. LukS-lukF genes were detected in over 58% of the strains. ET-encoding genes were detected in over 39% of the strains and the most prevalent was etd. The fnbA gene was detected in over 59% of the strains. All MRSA isolates tested were positive for the mecA gene. LukS-lukF genes and the etd gene were commonly co-present in MRSA, while lukS-lukF genes and the fnbA gene were commonly co-present in Methicillin Sensitive S. aureus (MSSA) isolates. No significant difference was detected between the occurrence of lukS-lukF genes (P > 0.05) and the etd gene (P > 0.05) when comparing MRSA and MSSA. The occurrence of the fnbA gene was significantly more frequent in MSSA strains (P aureus is a common cause of infection. The prevalence of S. aureus nasal carriage in our cohort of patients from Ukraine was 40.4%. We found that 9.1% of the strains were classified as MRSA and all MRSA isolates tested positive for the mecA gene

Transmission of methicillin-resistant Staphylococcus aureus to household contacts

NARCIS (Netherlands)

F.P.N. Mollema (Femke); J.H. Richardus (Jan Hendrik); M.D. Behrendt (Myra); N. Vaessen (Norbert); W. Lodder; W. Hendriks; H.A. Verbrugh (Henri); A. Voss (Andreas)

2010-01-01

textabstractThe frequency of and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) transmission from a MRSA index person to household contacts were assessed in this prospective study. Between January 2005 and December 2007, 62 newly diagnosed MRSA index persons (46 patients and 16

Determination of antimicrobial susceptibility patterns in Staphylococcus aureus strains recovered from patients at two main health facilities in Kabul, Afghanistan.

Science.gov (United States)

Naimi, Haji Mohammad; Rasekh, Hamidullah; Noori, Ahmad Zia; Bahaduri, Mohammad Aman

2017-11-29

Staphylococcus aureus (S. aureus) is a major pathogen implicated in skin and soft tissue infections, abscess in deep organs, toxin mediated diseases, respiratory tract infections, urinary tract infections, post-surgical wound infections, meningitis and many other diseases. Irresponsible and over use of antibiotics has led to an increased presence of multidrug resistant organisms and especially methicillin resistant Staphylococcus aureus (MRSA) as a major public health concern in Afghanistan. As a result, there are many infections with many of them undiagnosed or improperly diagnosed. We aimed to establish a baseline of knowledge regarding the prevalence of MRSA in Kabul, Afghanistan, as well as S. aureus antimicrobial susceptibility to current available antimicrobials, while also determining those most effective to treat S. aureus infections. Samples were collected from patients at two main Health facilities in Kabul between September 2016 and February 2017. Antibiotic susceptibility profiles were determined by the disc diffusion method and studied using standard CLSI protocols. Out of 105 strains of S. aureus isolated from pus, urine, tracheal secretions, and blood, almost half (46; 43.8%) were methicillin-sensitive Staphylococcus aureus (MSSA) while 59 (56.2%) were Methicillin-resistant Staphylococcus aureus (MRSA). All strains were susceptible to vancomycin. In total, 100 (95.2%) strains were susceptible to rifampicin, 96 (91.4%) susceptible to clindamycin, 94 (89.5%) susceptible to imipenem, 83 (79.0%) susceptible to gentamicin, 81(77.1%) susceptible to doxycycline, 77 (77.1%) susceptible to amoxicillin + clavulanic acid, 78 (74.3%) susceptible to cefazolin, 71 (67.6%) susceptible to tobramycin, 68 (64.8%) susceptible to chloramphenicol, 60 (57.1%) were susceptible to trimethoprim-sulfamethoxazole, 47 (44.8%) susceptible to ciprofloxacin, 38 (36.2%) susceptible to azithromycin and erythromycin, 37 (35.2%) susceptible to ceftriaxone and 11 (10.5%) were

Molecular epidemiology of clinical and carrier strains of methicillin resistant Staphylococcus aureus (MRSA in the hospital settings of north India

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Dar Mohammad J

2006-09-01

and the ciprofloxacin (Cf and erythromycin (E resistance seemed to be chromosomal mediated. In one of the experiments, plasmid pJMR1O from Staphylococcus aureus coding for ampicillin (A, gentamicin (G and amikacin (Ak resistance was transformed into Escherichia coli. The minimal inhibitory concentrations (MICs for A and G were lower in E. coli than in S. aureus. However, the MIC for Ak was higher in E. coli transformants than in S. aureus. Conclusion There is a progressive increase in MRSA prevalence and multi-drug resistance in staphylococci. Vancomycin is still the drug of choice for MRSA infections. The major reservoir of methicillin resistant staphylococci in hospitals is colonized/infected inpatients and colonized hospital workers. Resistance transfer from staphylococci to E. coli as well as from clinical to carrier staphylococci due to antibiotic stress seemed to be an alarming threat to antimicrobial chemotherapy.

Antiinfective therapy with a small molecule inhibitor of Staphylococcus aureus sortase.

Science.gov (United States)

Zhang, Jie; Liu, Hongchuan; Zhu, Kongkai; Gong, Shouzhe; Dramsi, Shaynoor; Wang, Ya-Ting; Li, Jiafei; Chen, Feifei; Zhang, Ruihan; Zhou, Lu; Lan, Lefu; Jiang, Hualiang; Schneewind, Olaf; Luo, Cheng; Yang, Cai-Guang

2014-09-16

Methicillin-resistant Staphylococcus aureus (MRSA) is the most frequent cause of hospital-acquired infection, which manifests as surgical site infections, bacteremia, and sepsis. Due to drug-resistance, prophylaxis of MRSA infection with antibiotics frequently fails or incites nosocomial diseases such as Clostridium difficile infection. Sortase A is a transpeptidase that anchors surface proteins in the envelope of S. aureus, and sortase mutants are unable to cause bacteremia or sepsis in mice. Here we used virtual screening and optimization of inhibitor structure to identify 3-(4-pyridinyl)-6-(2-sodiumsulfonatephenyl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole and related compounds, which block sortase activity in vitro and in vivo. Sortase inhibitors do not affect in vitro staphylococcal growth yet protect mice against lethal S. aureus bacteremia. Thus, sortase inhibitors may be useful as antiinfective therapy to prevent hospital-acquired S. aureus infection in high-risk patients without the side effects of antibiotics.

[Prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. An international view].

Science.gov (United States)

Szabó, Rita

2016-07-03

Methicillin-resistant Staphylococcus aureus is one of the most important pathogens of healthcare and long-term care-associated infections over the world, resulting high morbidity, mortality and extra costs in these settings. The authors analyze the prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. Systematic review using PubMed, ScienceDirect and Cochrane Library CENTRAL databases between January 1, 2006 and December 31, 2015 was performed. In the past ten years methicillin-resistant Staphylococcus aureus prevalence in European long-term care facilities (12.6%) was lower than in North America (33.9%). The most frequent predisposing factor was previous antimicrobial therapy, hospital admission and infection/colonisation, chronic wounds, and high care need. Based on the results, the prevention and control of methicillin-resistant Staphylococcus aureus is an important public health priority in the European and Hungarian long-term care facilities.

Evaluation of combinations of putative anti-biofilm agents and antibiotics to eradicate biofilms of Staphylococcus aureus and Pseudomonas aeruginosa.

Science.gov (United States)

Belfield, Katherine; Bayston, Roger; Hajduk, Nadzieja; Levell, Georgia; Birchall, John P; Daniel, Matija

2017-09-01

To evaluate potential anti-biofilm agents for their ability to enhance the activity of antibiotics for local treatment of localized biofilm infections. Staphylococcus aureus and Pseudomonas aeruginosa in vitro biofilm models were developed. The putative antibiotic enhancers N-acetylcysteine, acetylsalicylic acid, sodium salicylate, recombinant human deoxyribonuclease I, dispersin B, hydrogen peroxide and Johnson's Baby Shampoo (JBS) were tested for their anti-biofilm activity alone and their ability to enhance the activity of antibiotics for 7 or 14 days, against 5 day old biofilms. The antibiotic enhancers were paired with rifampicin and clindamycin against S. aureus and gentamicin and ciprofloxacin against P. aeruginosa. Isolates from biofilms that were not eradicated were tested for antibiotic resistance. Antibiotic levels 10× MIC and 100× MIC significantly reduced biofilm, but did not consistently eradicate it. Antibiotics at 100× MIC with 10% JBS for 14 days was the only treatment to eradicate both staphylococcal and pseudomonal biofilms. Recombinant human deoxyribonuclease I significantly reduced staphylococcal biofilm. Emergence of resistance of surviving isolates was minimal and was often associated with the small colony variant phenotype. JBS enhanced the activity of antibiotics and several other promising anti-biofilm agents were identified. Antibiotics with 10% JBS eradicated biofilms produced by both organisms. Such combinations might be useful in local treatment of localized biofilm infections. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Phytochemical Prospection and Modulation of Antibiotic Activity In Vitro by Lippia origanoides H.B.K. in Methicillin Resistant Staphylococcus aureus

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Humberto Medeiros Barreto

2014-01-01

Full Text Available The Lippia origanoides H.B.K. ethanol extract (LOEE and hexane (LOHEX, dichloromethane (LODCM, and ethyl acetate (LOEA fractions were tested for their antimicrobial activity alone or in combination with antibiotics against a methicillin resistant Staphylococcus aureus (MRSA strain. The natural products did not show antimicrobial activity against multidrug resistant strain at the clinically significant concentrations tested. However, a modulatory effect in the antibacterial activity of the neomycin and amikacin was verified when LOEE, LOHEX and LODCM were added to the growth medium at subinhibitory concentrations. A similar modulation was found when the natural products were changed for chlorpromazine, an inhibitor of bacterial efflux pumps, suggesting the involvement of resistance mediated by efflux system in the MRSA tested. The fractions LOHEX and LODCM showed a modulatory activity bigger than their majority compounds (carvacrol, thymol, and naringenin, indicating that this activity is not due to their majority compounds only, but it is probably due to a synergism between their chemical components. These results indicate that L. origanoides H.B.K. can be a source of phytochemicals able to modify the phenotype of resistance to aminoglycosides in MRSA.

Methicillin resistance in Staphylococcus aureus : a review of the ...

African Journals Online (AJOL)

Methicillin resistance in Staphylococcus aureus : a review of the molecular epidemiology, clinical significance and laboratory detection methods. ... Added to this burden is the emergence of more virulent strains of community-associated MRSA (CAMRSA) which at the turn of the century, has been increasingly reported to ...

New epidemiology of Staphylococcus aureus infection in Asia.

Science.gov (United States)

Chen, C-J; Huang, Y-C

2014-07-01

Not only is Asia the most populous region in the world, but inappropriate therapy, including self-medication with over-the-counter antimicrobial agents, is a common response to infectious diseases. The high antibiotic selective pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens. Indeed, Asia is among the regions with the highest prevalence rates of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in the world. Most hospitals in Asia are endemic for multidrug-resistant methicillin-resistant S. aureus (MRSA), with an estimated proportion from 28% (in Hong Kong and Indonesia) to >70% (in Korea) among all clinical S. aureus isolates in the early 2010s. Isolates with reduced susceptibility or a high level of resistance to glycopeptides have also been increasingly identified in the past few years. In contrast, the proportion of MRSA among community-associated S. aureus infections in Asian countries varies markedly, from 35%. Two pandemic HA-MRSA clones, namely multilocus sequence type (ST) 239 and ST5, are disseminated internationally in Asia, whereas the molecular epidemiology of CA-MRSA in Asia is characterized by clonal heterogeneity, similar to that in Europe. In this review, the epidemiology of S. aureus in both healthcare facilities and communities in Asia is addressed, with an emphasis on the prevalence, clonal structure and antibiotic resistant profiles of the MRSA strains. The novel MRSA strains from livestock animals have been considered to constitute a public health threat in western countries. The emerging livestock-associated MRSA strains in Asia are also included in this review. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

Structural characterization of Staphylococcus aureus biotin protein ligase and interaction partners: an antibiotic target.

Science.gov (United States)

Pendini, Nicole R; Yap, Min Y; Traore, D A K; Polyak, Steven W; Cowieson, Nathan P; Abell, Andrew; Booker, Grant W; Wallace, John C; Wilce, Jacqueline A; Wilce, Matthew C J

2013-06-01

The essential metabolic enzyme biotin protein ligase (BPL) is a potential target for the development of new antibiotics required to combat drug-resistant pathogens. Staphylococcus aureus BPL (SaBPL) is a bifunctional protein, possessing both biotin ligase and transcription repressor activities. This positions BPL as a key regulator of several important metabolic pathways. Here, we report the structural analysis of both holo- and apo-forms of SaBPL using X-ray crystallography. We also present small-angle X-ray scattering data of SaBPL in complex with its biotin-carboxyl carrier protein substrate as well as the SaBPL:DNA complex that underlies repression. This has revealed the molecular basis of ligand (biotinyl-5'-AMP) binding and conformational changes associated with catalysis and repressor function. These data provide new information to better understand the bifunctional activities of SaBPL and to inform future strategies for antibiotic discovery. © 2013 The Protein Society.

Resistance to Antibiotics in Strains of Staphylococcus spp., Enterococcus spp. and Escherichia coli Isolated from Rectal Swabs of Pigs

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M. Kolář

2008-01-01

Full Text Available The study aimed at determining the level of resistance of selected bacterial species (Staphylococcus spp., Enterococcus spp., Escherichia coli isolated from rectal swabs of pigs to antimicrobial agents. The tested strains were isolated from piglets aged 7 to 30 days. Bacterial species were identified by standard microbiological techniques and susceptibility to antibiotics was determined quantitatively by the standard microdilution method. Resistance of the Staphylococcus aureus strain to oxacillin was confirmed by detection of the mecA gene and PBP2a. A total of 115 Staphylococcus spp. isolates were collected. In the case of Staphylococcus aureus, the methicillin-resistant strain (MRSA was identified. Moreover, higher frequency of coagulase-negative staphylococci with minimum inhibitory concentration of oxacillin ≥ 0.5 mg/l was noticed. Inducible resistance to clindamycin in the Staphylococcus hominis strain was also detected. The strains of Enterococcus spp. (61 isolates exhibited high resistance to tetracycline (98.5%, erythromycin (86.8% and chloramphenicol (54.4%. Vancomycin-resistant enterococci were not isolated. In the case of Escherichia coli strains (111 isolates, higher frequency of resistant strains to tetracycline (81.1% and ampicillin (62.2% was documented. Resistance to fluoroquinolones and production of broad-spectrum β-lactamases was not noticed. The presented study may be considered as a pilot project assessing the prevalence of resistant bacteria in piglets kept on a single farm. It demonstrated the presence of resistant strains of Staphylococcus spp., including one MRSA strain, Enterococcus spp. and Escherichia coli. These strains may be present as a result of postnatal colonization with both bacterial microflora of dams and environmental microflora.

Antibiotic resistance profile of staphylococci from clinical sources ...

African Journals Online (AJOL)

Infants, children and the aged are among the groups most vulnerable to microbial infections more so when these microbial agents become resistant to antimicrobials. The antibiotic resistant profile of Staphylococcus aureus and selected coagulase negative staphylococci were determined by standard methods. Of the 178 ...