Resistencia a la meticilina y producción de biopelícula en aislamientos clínicos de Staphylococcus aureus y Staphylococcus coagulasa negativa en México / Methicillin resistance and biofilm production in clinical isolates of Staphylococcus aureus and coagulase-negative Staphylococcus in México

Resumen Introducción. Las infecciones por Staphylococcus aureus y Staphylococcus coagulasa negativa multirresistentes a los antibióticos y asociadas con la atención en salud tienen un gran impacto epidemiológico por su alta morbimortalidad; además, se han relacionado con la formación de biopelículas, lo cual también se asocia con la resistencia a los antimicrobianos. Objetivo. Determinar la resistencia a la meticilina y cuantificar la producción de biopelículas para establecer su posible relación con los aislamientos clínicos de S. aureus y Staphylococcus coagulasa negativa. Materiales y métodos. Se estudiaron 11 cepas de S. aureus y 12 de Staphylococcus coagulasa negativa. La resistencia a la meticilina se determinó con discos de cefoxitina tomando como valores de referencia los estándares del Clinical Laboratory Standards Institute (CLSI) de 2018. La producción de biopelícula se cuantificó con cristal violeta. Los genes mecA e icaADBC se identificaron mediante reacción en cadena de la polimerasa (PCR), y se hizo un análisis bivariado con la prueba de ji al cuadrado y el coeficiente V de Cramér, utilizando el programa SPSS™, versión 20.0. Resultados. Nueve cepas de S. aureus fueron resistentes a la meticilina (SARM) y dos fueron sensibles. Ocho cepas de Staphylococcus coagulasa negativa fueron resistentes y cuatro fueron sensibles. El genotipo mecA se encontró en ocho de las nueve cepas de S. aureus y en seis de las ocho de Staphylococcus coagulasa negativa resistentes a meticilina. Todas las cepas formaron biopelícula. Diez cepas de S. aureus y 11 de Staphylococcus coagulasa negativa presentaron el genotipo icaADCB. No se encontró asociación entre la resistencia a meticilina y la formación de biopelícula. Conclusiones. La cefoxitina es suficiente para determinar el fenotipo resistente a meticilina y se asoció con el genotipo mecA. Las cepas resistentes a la meticilina y poseedoras del gen mecA pueden presentar un mecanismo de resistencia alterno. Los dos grupos de cepas formadoras de biopelícula se relacionaron con la presencia del operón icaADCB. La formación de biopelícula y la resistencia a la meticilina se expresaron como características independientes en los dos grupos de cepas.

Abstract Introduction: Infections associated with health care caused by S. aureus and coagulase- negative Staphylococci multi-resistant to antibiotics cause a high epidemiological impact due to their high morbidity and mortality. Biofilm formation, which has been associated with antimicrobial resistance, can also occur. Objectives: To determine methicillin resistance and to quantify the biofilm production to establish if there is a relationship in clinical isolates of S. aureus and coagulase-negative Staphylococci. Material and methods: A total of 11 strains of S. aureus and 12 of coagulase-negative Staphylococci were studied. Methicillin resistance was determined with cefoxitin discs and the Clinical Laboratory Standards Institute (CSLI), 2018 reference values. Biofilm production was quantified by the crystal violet method. The mecA and icaADBC genes were identified by PCR. A bivariate analysis was performed with chi-square (c2) and Cramér's V statistical tests, using SPSS™, version 20.0 software. Results: Nine S. aureus strains were methicillin-resistant and two were sensitive. Eight coagulase-negative Staphylococci strains were resistant and four were sensitive. The mecA genotype was found in eight of the nine S. aureus resistant strains and six of eight resistant coagulase-negative Staphylococci. All strains formed biofilms. Ten strains of S. aureus and 11 of coagulase-negative Staphylococci presented the icaADCB genotype. No association was found between methicillin-resistance and biofilm formation. Conclusions: Cefoxitin is enough to define the resistance phenotype and is associated with the mecA genotype. All strains formed biofilms and were related to the presence of the icaADCB operon. Biofilm formation and methicillin resistance were independent features in both groups of strains.

Treatment of Mycobacterium Abscessus Pulmonary Disease / 대한내과학회지

Mycobacterium abscessus is the second most important pathogen in pulmonary disease caused by nontuberculous mycobacteria (NTM), following Mycobacterium avium. Mycobacterium abscessus is classified into three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. Mycobacterium abscessus is the most difficult to treat NTM due to its resistance to many antibiotics. Treatment should include an initial regimen of 2–3 injectable and oral antibiotics for several weeks or months, followed by inhaled amikacin and 1–3 oral antibiotics, depending on the subspecies and drug susceptibility patterns, including macrolide susceptibility. The continuation phase should be continued for a minimum of 12 months after culture conversion. Suitable injectable antibiotics include amikacin, imipenem, cefoxitin, and tigecycline, while oral antibiotics include macrolides (azithromycin or clarithromycin), clofazimine, linezolid, and moxifloxacin. Surgery can be a useful adjunctive therapy for some patients with refractory disease. However, the overall treatment prognosis is still unsatisfactory. Therefore, novel and more effective interventions are required for the treatment of M. abscessus pulmonary disease.

Ceftaroline resistance in Staphylococcus pseudintermedius gene mecA carriers / Resistência à ceftarolina em Staphylococcus pseudintermedius portadores do gene mecA

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)

Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)

Cefoxitin plus levofloxacin for prevention of severe infection after transrectal prostate biopsy / 中华男科学杂志

<p><b>Objective</b>To evaluate the effect of cefoxitin prophylactic in reducing the incidence of severe infection after transrectal prostate biopsy (TRPB).</p><p><b>METHODS</b>This retrospective study included 155 cases of TRPB with a 5-day administration of oral levofloxacin at 200 mg bid (the control group) and another 167 cases with a 3-day administration of oral levofloxacin at the same dose plus intravenous cefoxitin at 2.0 g 2 hours before TRPB (the experimental group) according to the distribution characteristics of drug-resistance bacteria in our department. The patients of the control and experimental groups were aged (68.68 ± 8.12) and (68.72 ± 7.51) years, with PSA levels of (19.78 ± 21.57) and (21.15 ± 42.63) μg/L, involving (11.68 ± 1.44) and (11.77±1.02) biopsy cores, respectively. Comparisons were made between the two groups of patients in the incidence rate of severe infection, which was defined as lower urinary track symptoms plus the systemic inflammatory response syndrome (SIRS) within 7 days after TRPB.</p><p><b>RESULTS</b>The incidence rate of postoperative severe infection was significantly lower in the experimental group than in the control (0.6% ［1/167］ vs 5.8% ［9/155］, P < 0.05). Blood cultures revealed positive E-coli strains in 6 cases in the control group, including 5 ESBL-positive and 4 quinolone-resistant and amikacin-sensitive cases, all sensitive to cefoxitin, cefoperazone/sulbactam and imipenem. The only one case of severe infection was shown to be negative in blood culture.</p><p><b>CONCLUSIONS</b>Preoperative intravenous administration of cefoxitin according to the specific distribution characteristics of drug-resistance bacteria can significantly reduce the incidence of severe infection after TRPB.</p>

Perfil de resistencia antimicrobiana en bacilos Gram negativos no fermentadores aislados en fuentes hídricas / Antimicrobial resistance profile in non-fermenting gram negative bacilli isolated in water resources

La amplia distribución de los bacilos gram negativos no fermentadores en medios ambientales como el agua y especies vegetales cobra importancia al ser reconocidos como agentes causales de enfermedades en pacientes inmunocomprometidos, de allí la relevancia del porque debemos conocer la prevalencia y perfil de susceptibilidad de estos microorganismos en ambientes no hospitalarios. Materiales y Métodos: Estudio transversal, realizado en muestras hídricas de fuentes naturales y artificiales de almacenamiento para el consumo humano en la ciudad de Bogotá y municipios aledaños. La identificación se realizó a través de pruebas IMVIC y el perfil de resistencia a través del método de kirby bauer o E-TEST®. Resultados: Se obtuvieron 42 muestras, 7 (16,6%) con aislamientos de interés: 3 (60%) Pseudomonas spp, 2 (20%) Acinetobacter spp, 1 (10%) Sphingomonas paucimobilis y 1 (10%) Pantoea spp. El 70% presento resistencia a la ceftriaxona, el 30% a cefoxitina, 20% a gentamicina, 10% a ciprofloxacina y 10% a piperacilina-tazobactam. No se presentó resistencia a imipenem. Conclusión: 5 de 7 aislamientos revelaron un BGNNF de importancia en infección en humanos, siendo importante la resistencia encontrada a la ceftriaxona.

The wide distribution of non-fermenting gram negative bacilli in environmental media such as water and plants becomes important as they are recognized a cause of diseases in immunocompromised patients, that’s the reason why we should to know the prevalence and the susceptibility profile of these microorganisms in non-hospital environments. Materials and Methods: Cross-sectional study done with samples of natural and artificial water storage for human consumption in the city of Bogotá and surrounding municipalities. The identification was made through IMVIC tests and the resistance profile through the kirby bauer or E-TEST® method. Results: 42 samples were obtained, 7 (16.6%) with isolates of interest: 3 (60%) Pseudomonas spp, 2 (20%) Acinetobacter spp, 1 (10%) Sphingomonas paucimobilis and 1 (10%) Pantoea spp. The 70% had resistance to ceftriaxone, 30% to cefoxitin, 20% to gentamicin, 10% to ciprofloxacin and 10% to piperacillin-tazobactam. No resistance to imipenem was shown. Conclusion: 5 of 7 isolates revealed a BGNNF of importance in infection in humans, with an important resistance to ceftriaxone.

Staphylococcus aureus y estafilococo coagulasa negativa resistentes a la meticilina / Staphylococcus aureus and negative coagulase staphylococcus resistant to methicillin

Se realizó un estudio prospectivo de 47 cepas de estafilococo procedentes de muestras biológicas del Laboratorio de Microbiología del Hospital Provincial Docente Clinicoquirúrgico Saturnino Lora Torres de Santiago de Cuba, desde febrero hasta abril de 2017, con vistas a determinar la frecuencia de estafilococos resistentes a la meticilina. En la serie, el mayor número de los aislamientos correspondió a las muestras de secreciones y catéter; asimismo, los servicios con mayores aislamientos notificados fueron Ortopedia y Cirugía. Se observó una frecuencia elevada de cepas de Staphylococcus aureus y estafilococo coagulasa negativa, resistentes a meticilina

A prospective study of 47 staphylococcus stumps coming from biological samples of the Microbiology Laboratory in Saturnino Lora Torres Teaching Clinical Surgical Provincial Hospital was carried out in Santiago de Cuba, from February to April, 2017, aimed at determining the frequency of staphylococcus resistant to methicillin. In the series, the highest number of isolations corresponded to the samples of secretions and catheter; also, the services with more notified isolations were Orthopedics and Surgery. A high frequency of Staphylococcus aureus stumps and negative coagulase staphylococcus resistant to methicillin was observed

Rapid screening of pyogenic Staphylococcus aureus for confirmation of genus and species, methicillin resistance and virulence factors by using two novel multiplex PCR

Objectives: Emergence of methicillin resistant Staphylococcus aureus [MRSA] is a major medical problem of current era. These bacteria are resistant to most drugs and rapid diagnosis can provide a clear guideline to clinicians. They possess specific virulence factors and relevant information can be very useful. We designed this study to develop multiplex PCRs to provide rapid information

Methods: We studied 60 Staphylococcus aureus isolates and detected methicillin resistance by cefoxitin sensitivity and targeting of mecA gene. After initial studies with uniplex PCRs we optimized two multiplex PCRs with highly reproducible results. The first multiplex PCR was developed to confirm genus, species and methicillin resistance simultaneously, and the second multiplex PCR was for screening of virulence factors

Results: We found 38.33% isolates as methicillin resistant, a-toxin, the major cytotoxic factor, was detected in 40% whereas 6-hemolysin was found in 25% cases. Panton Valentine leucocidin was detected in 8.33% and toxic shock syndrome toxin in5% cases. The results of uniplex and multiplex PCRs were highly compatible

Conclusions: These two multiplex PCRs when run simultaneously can provide vital information about methicillin resistance and virulence status of the isolate within a few hours as compared to several days needed by routine procedures

Rapid Diagnosis of Mycobacterium abscessus Bacteremia Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry / 대한임상미생물학회지

Mycobacterium abscessus was isolated from cultures of seven blood samples from a 64-year-old diabetic female who was admitted due to steroid-unresponsive adrenal insufficiency. The isolates were difficult to identify using the conventional commercial systems, VITEK 2 (bioMérieux, France) or MicroScan (Siemens Healthcare Diagnostics, USA), but were rapidly identified as M. abscessus by a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based Bruker Biotyper system (Bruker Daltonics, USA). Identification of M. abscessus was confirmed by a reverse hybridizationbased assay (Genotype Mycobacterium CM/AS 12, Hain Lifescience) and direct sequencing of a heatshock protein gene. After removal of her central venous catheter, the patient was successfully treated with a combination therapy comprising clarithromycin, amikacin, cefoxitin, and imipenem. Our findings demonstrate that MALDI-TOF MS can facilitate rapid and accurate identification of M. abscessus from blood cultures, which enables prompt administration of appropriate therapy following catheter removal.

Molecular characterization and epidemiology of cefoxitin resistance among Enterobacteriaceae lacking inducible chromosomal ampC genes from hospitalized and non-hospitalized patients in Algeria: description of new sequence type in Klebsiella pneumoniae isolates

In this study, 922 consecutive non-duplicate clinical isolates of Enterobacteriaceae obtained from hospitalized and non-hospitalized patients at Bejaia, Algeria were analyzed for AmpC-type β-lactamases production. The ampC genes and their genetic environment were characterized using polymerase chain reaction (PCR) and sequencing. Plasmid incompatibility groups were determined by using PCR-based replicon typing. Phylogenetic grouping and multilocus sequence typing were determined for molecular typing of the plasmid-mediated AmpC (pAmpC) isolates.Of the isolates, 15 (1.6%) were identified as AmpC producers including 14 CMY-4- producing isolates and one DHA-1-producing Klebsiella pneumoniae. All AmpC-producing isolates co-expressed the broad-spectrum TEM-1 β-lactamase and three of them co-produced CTX-M and/or SHV-12 ESBL. Phylogenetic grouping and virulence genotyping of the E. coli isolates revealed that most of them belonged to groups D and B1. Multilocus sequence typing analysis of K. pneumoniae isolates identified four different sequence types (STs) with two new sequences: ST1617 and ST1618. Plasmid replicon typing indicates that bla CMY-4 gene was located on broad host range A/C plasmid, while LVPK replicon was associated with bla DHA-1. All isolates carrying bla CMY-4 displayed the transposon-like structures ISEcp1/AISEcp1-blaCMY-blc-sugE. Our study showed that CMY-4 was the main pAmpC in the Enterobacteriaceae isolates inAlgeria.

Profiling of antimicrobial resistance and plasmid replicon types in beta-lactamase producing Escherichia coli isolated from Korean beef cattle

In this study, 78 isolates of Escherichia coli isolated from Korean beef cattle farms were investigated for the production of extended-spectrum beta-lactamase (ESBL) and/or AmpC beta-lactamase. In the disc diffusion test with ampicillin, amoxicillin, cephalothin, ceftiofur, cefotaxime, ceftazidime, and cefoxitin, 38.5% of the isolates showed resistance to all of ampicillin, amoxicillin, and cephalothin. The double disc synergy method revealed that none of the isolates produced ESBL or AmpC beta-lactamases. DNA sequencing showed that all isolates encoded genes for TEM-1-type beta-lactamase. Moreover, 78.2% of the isolates transferred the TEM-1-type beta-lactamase gene via conjugation. In plasmid replicon typing of all donors, IncFIB and IncFIA were identified in 71.4% and 41.0% of plasmids, respectively. In transconjugants, IncFIB and IncFIA were the most frequent types detected (61.5% and 41.0%, respectively). Overall, the present study indicates that selection pressures of antimicrobials on beta-lactamases in beef cattle may be low relative to other livestock animals in Korea. Moreover, to reduce selection pressure and dissemination of beta-lactamase, the long-term surveillance of antimicrobial use in domestic beef cattle should be established.

Multicenter Study of Antimicrobial Susceptibility of Anaerobic Bacteria in Korea in 2012

BACKGROUND: Periodic monitoring of regional or institutional resistance trends of clinically important anaerobic bacteria is recommended, because the resistance of anaerobic pathogens to antimicrobial drugs and inappropriate therapy are associated with poor clinical outcomes. There has been no multicenter study of clinical anaerobic isolates in Korea. We aimed to determine the antimicrobial resistance patterns of clinically important anaerobes at multiple centers in Korea. METHODS: A total of 268 non-duplicated clinical isolates of anaerobic bacteria were collected from four large medical centers in Korea in 2012. Antimicrobial susceptibility was tested by the agar dilution method according to the CLSI guidelines. The following antimicrobials were tested: piperacillin, piperacillin-tazobactam, cefoxitin, cefotetan, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, metronidazole, and tigecycline. RESULTS: Organisms of the Bacteroides fragilis group were highly susceptible to piperacillin-tazobactam, imipenem, and meropenem, as their resistance rates to these three antimicrobials were lower than 6%. For B. fragilis group isolates and anaerobic gram-positive cocci, the resistance rates to moxifloxacin were 12-25% and 11-13%, respectively. Among B. fragilis group organisms, the resistance rates to tigecycline were 16-17%. Two isolates of Finegoldia magna were non-susceptible to chloramphenicol (minimum inhibitory concentrations of 16-32 mg/L). Resistance patterns were different among the different hospitals. CONCLUSIONS: Piperacillin-tazobactam, cefoxitin, and carbapemems are highly active beta-lactam agents against most of the anaerobes. The resistance rates to moxifloxacin and tigecycline are slightly higher than those in the previous study.

OXA-10 and GES-1 extended-spectrum beta-lactamases play a major role in causing antibiotic resistance of Pseudomonas aeruginosa isolated from nosocomial infections in Ismailia, Egypt

Background: Pseudomonas aeruginosa causes large percentages of nosocomial infections with high rates of treatment failure due to antibiotic resistance. The production of extended spectrum beta lactamases [ESBLs] is a principal mechanism of antibiotic resistance of this bacterium. Such infections represent a great challenge in our hospitals

Objectives: Application of phenotypic methods and PCR for detection of bla[OXA-10] and bla[GES-1] extended-spectrum beta-lactamases in Pseudomonas aeruginosa isolated from cases of nosocomial infections in Ismailia city, Egypt

Methodology: Forty five isolates of P. aeruginosa isolated from cases of surgical site infection were submitted for antibiotic susceptibility testing, followed by phenotypic screening for both OXA-10 and GES-1 beta lactamases using disc combination method of ceftazidime-clavulanic acid and cefotaxime- clavulanic acid disks. PCR targeting genes of these ESBLs was applied for more accurate detection

Results: The resistance rates were 100% for ampicillin, cefoxitin, cefuroxime, and cefazolin while for cefotaxime, ceftriaxone, ceftazidime and cefepime, the resistance reached 84.5%, 68.9%, 57.8% and 37.8%, respectively. Imipenem, ciprofloxacin and gentamicin were the most effective antibiotics as they had sensitivity rates of 77.8%, 68.9%, and 73.4%, respectively. Disc combination tests were positive in more than two thirds of isolates. PCR detected blaOXA-10 and blaGES-1 in fifteen and twelve isolates, respectively

Conclusion: ESBLs are still playing major role in marked antibiotic resistance P. aeruginosa against the extended beta lactam antibiotics in Ismailia, Egypt as OXA-10 and GES-1 beta lactamases were isolated at rates of 33.3% and 26.7%, respectively. The current study provides a new report for detection of GES-1 in Egypt

Screening of nasal carriage for Staphylococcus aureus and their resistance to oxacillin and cefoxitin among medical students in Karbala University

Objective: Carriage of Staphylococcus aureus, especially methicillin-resistant S. aureus [MRSA] is a problem within healthcare organizations and in the community. The aim of the study was to screen S. aureus carriage and their susceptibility to cefoxitin and oxacillin among medical students

Methods: A total of 100 nasal swabs were collected. Isolation and identification of the isolate as S. aureus was done using Gram stain, coagulase test and catalase test. S. aureus isolates were confirmed as MRSA using cefoxitin [30 micro g] disc and oxacillin [30 micro g] disc by Kirby- Bauer disc diffusion method on Mueller-Hinton agar. From 100 nasal swabs, 76 were coagulase negative Staphylococci and 20 were coagulase positive Staphylococci

Results: From 100 nasal swabs, 76 were coagulase negative Staphylococci and 20 were coagulase positive Staphylococci. From these, 60% and 40% were oxacillin- and cefoxitin-resistant isolates, respectively. The data obtained from this study revealed that there were carriers of MRSA among the medical students

Increase in the Prevalence of Carbapenem-Resistant Acinetobacter Isolates and Ampicillin-Resistant Non-Typhoidal Salmonella Species in Korea: A KONSAR Study Conducted in 2011

BACKGROUND: Antimicrobial surveillance is important for providing an up-to-date understanding of the epidemiology of antimicrobial resistance and for creating a forum for rational drug development. In this study, we analyzed antimicrobial test data generated in 2011 by hospitals and commercial laboratories participating in the Korean Nationwide Surveillance of Antimicrobial Resistance program (KONSAR). MATERIALS AND METHODS: Data on the results of susceptibility tests conducted in 32 hospitals and two commercial laboratories were analyzed. Data on isolates from patients admitted to an intensive care unit (ICU) and those admitted to other wards were compared. Intermediate susceptibility was not analyzed and duplicate isolates were excluded. RESULTS: Escherichia coli was the most prevalent organism identified in both the hospital and commercial laboratories. Among the hospital isolates, methicillin-resistant Staphylococcus aureus (MRSA), penicillin G-non-susceptible Streptococcus pneumoniae, and ampicillin-resistant Enterococcus faecium remained as prevalent as they were in 2009. The proportion of vancomycin-resistant E. faecium (VR-EFM) slightly decreased from 29% in 2009 to 23% in 2011. Resistance rates of Klebsiella pneumoniae to ceftazidime, cefoxitin, fluoroquinolone, and amikacin were 24%, 14%, 27%, and 8%, respectively. Resistance rates of Pseudomonas aeruginosa to fluoroquinolone, ceftazidime, imipenem, and amikacin were 33%, 20%, 22%, and 16%, respectively, whereas those of Acinetobacter spp. resistance were 71%, 66%, 64, and 51%, respectively. The prevalence of oxyimino-cephalosporin-resistant E. coli and K. pneumoniae, carbapenem-resistant Acinetobacter spp. and P. aeruginosa, MRSA, and VR-EFM among ICU isolates was higher than those among non-ICU isolates. Extended-spectrum beta-lactamase-producing E. coli and K. pneumoniae, imipenem-resistant P. aeruginosa, and VR-EFM were more prevalent among isolates from commercial laboratories than those from hospitals. Resistance rates of K. pneumoniae to ceftazidime and amikacin decreased from 32% and 24% in 2005 to 24% and 8% in 2011, respectively. The resistance rate of P. aeruginosa to amikacin decreased from 22% in 2005 to 16% in 2011. The proportion of imipenem-resistant Acinetobacter spp. increased from 16% in 2005 to 64% in 2011. CONCLUSIONS: The prevalence of MRSA, penicillin G-non-susceptible S. pneumoniae, and ampicillin-resistant E. faecium among clinical isolates tested in laboratories remained high. Multidrug resistance was more prevalent among isolates from ICUs. The prevalence of ceftazidime-resistant and amikacin-resistant K. pneumoniae and amikacin-resistant P. aeruginosa decreased after 2005, while the prevalence of imipenem-resistant Acinetobacter spp. increased.

Comparison of cefoxitin disk diffusion test and mecA gene PCR results for methicillin resistance detection in Staphylococcus intermedius group isolates from canine origin in Brazil

The study evaluated cefoxitin disk diffusion tests breakpoints and their correlation to mecA gene PCR results for detecting Methicillin-resistant Staphylococcus intermedius Group (MRSP) isolates from dogs in Brazil. Agreement using proposed breakpoint (resistant < 30 mm) was encouraging. The current study reinforces that an epidemiological breakpoint can be established to predict presence of MRSP.

Detection of methicillin-resistant Staphylococcus aureus directly by loop-mediated isothermal amplification and direct cefoxitin disk diffusion tests

We evaluated the utility of 2 methods for detection of methicillin-resistant Staphylococcus aureus [MRSA] directly from signal-positive blood culture bottles: loop-mediated isothermal amplification [LAMP] assay, and direct cefoxitin disk diffusion [DCDD] test using a 30 microg cefoxitin disk. In parallel, standard microbiological identification and oxacillin susceptibility testing with MecA PCR was performed. Of 60 blood cultures positive for Gram-positive cocci in clusters, LAMP [via detection of the FemA and MecA genes] showed 100% sensitivity and specificity for identification of MRSA/MSSA. When coagulase-negative staphylococci were tested, sensitivity for detection of methicillin resistance was 91.7% and specificity was 100%. DCDD along with direct tube coagulase assay detected only 80.6% of MRSA/MSSA. LAMP showed higher diagnostic accuracy although DCDD was more cost-effective and did not require additional reagents or supplies

Clinical isolates of Mycobacterium abscessus in Guangzhou area most possibly from the environmental infection showed variable susceptibility / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mycobacterium abscessus (M. abscessus) can cause a variety of human infections, involving the lung, skin and soft tissues, and is generally believed to be acquired from environmental sources. The aim of this study was to investigate the molecular diversity and antibiotic susceptibility of M. abscessus isolates as the basis for strategies to improve control and management of infection.</p><p><b>METHODS</b>Seventy M. abscessus isolates from patients attending the Guangzhou Thoracic Hospital were identified from 2003 to 2005 by biochemical tests, gas chromatography, polymerase chain reaction (PCR)-restriction analysis (PRA) of heat shock protein gene hsp65, and sequencing of the quinolone resistance determining regions (QRDRs) of gyrA. Susceptibilities to six antibiotics were determined by micro-broth dilution. Isolates were genotyped using randomly amplified polymorphic DNA (RAPD) analysis.</p><p><b>RESULTS</b>Most isolates (63/70; 90%) were susceptible to amikacin but rates of susceptibility to other antibiotics varied from moderate, clarithromycin (60%) and imipenem (43%), to low for ciprofloxacin and ofloxacin (3%), and 87% of isolates had intermediate susceptibility to cefoxitin. RAPD analysis showed that the 70 clinical isolates displayed 69 unique RAPD patterns.</p><p><b>CONCLUSIONS</b>The high genetic diversity of isolates suggests that they are not transmitted from person to person but, presumably, are acquired independently from environmental sources. M. abscessus isolates displayed variable levels of susceptibility to all antibiotics tested, other than amikacin, indicating a need for routine susceptibility testing to guide treatment.</p>

Preventive administration of antibiotics to patients with benign prostatic hyperplasia before urodynamic examination / 中华男科学杂志

<p><b>OBJECTIVE</b>To discuss the effect and safety of preventive administration of antibiotics to patients with benign prostatic hyperplasia (BPH) before urodynamic examination.</p><p><b>METHODS</b>A total of 256 BPH patients to undergo urodynamic examination were randomly divided into a control group (n = 118) and a trial group (n = 138). The former received no pre-treatment while the latter were given cefoxitin sodium iv at 1.0 g 30 minutes before complete urodynamic examination. Then we compared the incidence rates of urinary tract infection between the two groups.</p><p><b>RESULTS</b>Statistically significant differences were found in the incidence rate of urinary tract infection between the control and trial groups (20.3% [24/118] vs 7.3% [10/138], P < 0.01), as well as in those with diabetes mellitus (6.7% [3/45] vs 23.5% [8/34], P < 0.05), those with residual urine > 50 ml (5.4% [3/56] vs 18.5% [10/54], P < 0.05), and those with both diabetes mellitus and residual urine (9.5% [2/21] vs 44.4% [8/18], P < 0.05). Only 3 patients (2.2%) in the trial group had mild adverse drug reactions.</p><p><b>CONCLUSION</b>For BPH patients, particularly those with diabetes mellitus and residual urine, preventive administration of antibiotics before urodynamic examination is safe and can effectively protect the patients against urinary tract infection.</p>

The Study of Aerobic Bacterial Culture and Antibiotic Susceptibility in Epidermal Cysts / 대한피부과학회지

BACKGROUND: Epidermal cyst is a common acquired skin cyst. When such cysts may be inflamed, they are often referred to as being infected. To clarify the etiology of inflamed epidermal cysts, several studies have carried bacteriology of inflamed and uninflamed epidermal cyst and sought to identify the role of micro-organisms. OBJECTIVE: The aim of this study is to evaluate the bacterial influences on inflammatory process of epidermal cysts and the antibiotic sensitivity of cultured aerobic bacteria in epidermal cysts. METHODS: We carried out the bacterial cultures using sterile swabbing internal materials in each cyst which has been incised after surgical removals of epidermal cyst. An inflamed epidermal cyst was defined as a known cyst that developed a fluctuant soft-tissue swelling surrounded by the erythema and contained a localized collection of purulent material. For the aerobic culture, samples were cultured on blood agar plates, McConkey agar plate and chocolate agar plates in 5% CO2 at 35degrees C for 5 days. Colonies formed were identified based on VITEK2 system. Then antimicrobial susceptibility test were also done on VITEK2 system. RESULTS: Total of 100 epidermal cyst specimens from 96 patients (67 men and 29 women) were involved had confirmed histopathological findings by dermatologists. Seventy were from face and neck, 24 from trunk, 4 from the extremities, 2 from buttock. Of the 53 inflamed cysts, 30 (56.6%) yielded bacterial growth. On the other hand, from the 47 uninflamed cysts, 15 (31.9%) cyst resulted in bacterial growth (p=0.013). The predominant bacteria from inflamed and uninflamed cyst were coagulase-negative Staphylococci (32 isolate of 45 specimens, 71.1%). All cultured bacteria were susceptible to almost all of antibiotics except amoxicillin/clavulanic acid, ampicillin, benzylpenicillin, cefoxitin, cephalothin, fucidic acid, piperacillin, piperacillin/Tazobactam. CONCLUSION: Our study showed that CoNS was predominant in inflamed cysts, which strongly suggests that aerobic bacteria play a role in the inflammatory process and treatment with antibiotics is necessary for epidermal cyst.