Use of Intravenous Minocycline for the Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) and Resistant Gram-Negative Organisms

ABSTRACT Imipenem is a beta-lactam antibiotic mainly active against gram-negative bacterial pathogens and also could cause cell wall impairment in methicillin-resistant Staphylococcus aureus(MRSA). However, related antibacterial mechanisms of imipenem on MRSA and mixed infections of MRSA and gram-negative bacteria are relatively poorly revealed. This study was to identify proteins in the MRSA response to subminimal inhibitory concentrations (sub-MICs) of imipenem treatment. Our results showed that 240 and 58 different expression proteins (DEPs) in sub-MICs imipenem-treated S3 (a standard MRSA strain) and S23 (a clinical MRSA strain) strains were identified through the isobaric tag for relative and absolute quantitation method when compared with untreated S3 and S23 strains, respectively, which was further confirmed by multiple reactions monitoring. Our result also demonstrated that expressions of multiple DEPs involved in cellular proliferation, metabolism and virulence were significantly changed in S3 and S23 strains, which was proved by gene ontology annotations and qPCR analysis. Further, transmission electron microscopy and scanning electron microscopy analysis showed cell wall deficiency, cell lysis and abnormal nuclear mitosis on S23 strain. Our study provides important information for understanding the antibacterial mechanisms of imipenem on MRSA and for better usage of imipenem on patients co-infected with MRSA and other multidrug-resistant gram-negative bacteria.

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Polymerase Chain Reaction for the Rapid Detection of Cerebrospinal Fluid Shunt or Ventriculostomy Infections

Neurosurgery ◽

10.1227/01.neu.0000186038.98817.72 ◽

2005 ◽

Vol 57 (6) ◽

pp. 1237-1243 ◽

Cited By ~ 36

Author(s):

Jason T. Banks ◽

Suman Bharara ◽

R Shane Tubbs ◽

Charles L. Wolff ◽

G Yancey Gillespie ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Polymerase Chain Reaction ◽

Cerebrospinal Fluid ◽

16S Rrna ◽

Methicillin Resistant Staphylococcus Aureus ◽

Propionibacterium Acnes ◽

Chain Reaction ◽

Gram Negative ◽

Methicillin Resistant ◽

Polymerase Chain

AbstractOBJECTIVE:Infection after cerebrospinal fluid (CSF) shunts or ventriculostomies is a common complication associated with significant morbidity and mortality. Polymerase chain reaction (PCR) is a powerful molecular technique that allows rapid and precise amplification of bacterial deoxyribonucleic acid (DNA) and has proven a powerful tool in the detection of a wide variety of clinically important infectious diseases. We analyzed specimens of CSF derived from ventriculoperitoneal shunts or external ventricular drains by using both conventional cultures and PCR and report herein our preliminary results.METHODS:We selected 86 CSF samples from adult patients who underwent either shunt tap or routine surveillance cultures of their ventriculostomy. These specimens were chosen from a larger group of 300 specimens that were routinely collected (many serially) in our clinical practice. They were chosen because clinical suspicion of infection was increased because of either patient signs and symptoms (fever, stiff neck, lethargy, worsening neurological examination) or preliminary laboratory analysis of CSF data (increased white blood cell count, increased protein level, decreased glucose). We considered this subgroup optimal to efficiently initiate our investigation of the correlation of PCR and culture results. CSF was increased by using standard culture techniques and by using PCR. Samples of CSF that were to undergo PCR had DNA extracted, purified, and amplified for 16S rRNA using primers 16S-Forward and 16S-Reverse of conserved sequence regions of all bacteria. DNA was PCR-amplified for 30 cycles. One microliter of the first PCR product was subjected to nested PCR using primers specific for gram-positive and gram-negative bacteria. Samples were also subjected to PCR amplification for specific detection of Propionibacterium acnes, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus using specific primers for 16S rRNA Propionibacterium, nuclease gene of Staphylococcus, and Mec gene of methicillin-resistant Staphylococcus aureus.RESULTS:For 18 of 86 specimens (21%), both the culture and PCR were positive. For 30 of 86 specimens (35%), both the PCR and culture results were negative. For 42 of 86 specimens (49%), cultures were negative and PCR was positive. There were no positive culture results with negative PCR results. Most negative culture/positive PCR cases occurred after prolonged intravenous antibiotics. Of the 56 PCR-positive specimens, 30 were positive for Propionibacterium acnes, whereas 40 were positive for Staphylococcus aureus. Of the Staphylococcus aureus-positive specimens, two were positive for methicillin resistant-Staphylococcus aureus. Among the 56 PCR-positive specimens, 30 were positive for both Propionibacterium acnes and Staphylococcus aureus; gram-negative organisms were not detected by any method in these specimens.CONCLUSION:These preliminary data suggest that PCR is a highly sensitive, rapid, and potentially promising modality for the detection and treatment of CSF shunt ventriculostomy infection.

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What is the Rate of Methicillin-resistant Staphylococcus aureus and Gram-negative Infections in Open Fractures?

Clinical Orthopaedics and Related Research ◽

10.1007/s11999-013-2855-4 ◽

2013 ◽

Vol 471 (10) ◽

pp. 3135-3140 ◽

Cited By ~ 35

Author(s):

Antonia F. Chen ◽

Verena M. Schreiber ◽

Wesley Washington ◽

Nalini Rao ◽

Andrew R. Evans

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Open Fractures ◽

Gram Negative ◽

Methicillin Resistant

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Adult Native Joint Septic Arthritis: A Nine-Year Retrospective Analysis in a Portuguese University Hospital

Acta Médica Portuguesa ◽

10.20344/amp.12998 ◽

2021 ◽

Vol 34 (13) ◽

Author(s):

Ana Cipriano ◽

Fábio Videira Santos ◽

Rita Dias ◽

André Carvalho ◽

Ernestina Reis ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Septic Arthritis ◽

Retrospective Analysis ◽

Methicillin Resistant Staphylococcus Aureus ◽

Empirical Treatment ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Methicillin Resistant ◽

Wide Range ◽

Amoxicillin Clavulanate

Introduction: Septic arthritis of a native joint represents a medical emergency. Drainage and effective antibiotic treatment are critical to avoid joint destruction and long-term impairment. The aim of this study was to evaluate epidemiological and clinical characteristics of patients with the diagnosis of septic arthritis to help establish local guidelines for empirical antibiotic treatment.Material and Methods: Retrospective analysis of adult patients admitted at Centro Hospitalar Universitário do Porto from 2009 to 2017 with suspected native joint septic arthritis. Relevant demographics, microbiology findings and respective antibiotic susceptibilities were analysed.Results: Ninety-seven patients, predominantly males (59.8%) with a median age of 61 years old were included. The most commonly reported comorbidity associated with septic arthritis was diabetes mellitus (20.6%). The knee was the most commonly affected joint (71.1%). Arthrocentesis was performed in all patients, but only 50.5% had positive microbial growth in the synovial fluid. Staphylococcus aureus was the most frequently identified microorganism, 86% of which were methicillin susceptible. Gram-negative bacteria were the causative agent in 15% of cases. A wide range of empirical antibiotic regimens were prescribed with a combination of vancomycin/carbapenem being the most common (30.9%). Analysis of antibiotic susceptibility profiles revealed that amoxicillin/clavulanate would have been appropriate as the initial regimen in 89% of cases.Discussion: The main causative pathogen was Staphylococcus aureus, with methicillin resistant Staphylococcus aureus remaining rare. The proportion of Gram-negative bacteria implies that these agents should be covered by empirical treatment, although no case of Pseudomonas infection has been identified. Therefore, antipseudomonal coverage is not necessary in empirical regimens.Conclusion: Routine coverage of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa is not warranted but must be considered when specific risk factors are found. Amoxicillin/clavulanate can provide adequate antibiotic coverage as an empirical treatment for adult native joint septic arthritis. Its use may allow a reduction in use of broader spectrum antibiotics.

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