The ABCF family protein Msr(A) confers high resistance to macrolides but only low resistance to ketolides in staphylococci. Mutations in conserved functional regions of ClpX as well as deletion of clpX significantly increased Msr(A)-mediated resistance to the ketolide antibiotic telithromycin. ClpX is the chaperone component of the ClpXP two-component proteolytic system. Nevertheless, no changes in resistance were observed in a clpP knockout strain expressing msr(A), demonstrating that ClpX affects Msr(A) independently of ClpP.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacterial Proteins genetics   metabolism   MeSH
• Ketolides pharmacology   MeSH
• Macrolides pharmacology   MeSH
• Mutation MeSH
• Staphylococcus aureus drug effects   metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Proteins MeSH
• Ketolides MeSH
• Macrolides MeSH
• telithromycin MeSH Browser

The lincomycin biosynthetic gene lmbX was deleted in Streptomyces lincolnensis ATCC 25466, and deletion of this gene led to abolition of lincomycin production. The results of complementation experiments proved the blockage in the biosynthesis of lincomycin precursor 4-propyl-L-proline. Feeding this mutant strain with precursor derivatives resulted in production of 4'-butyl-4'-depropyllincomycin and 4'-pentyl-4'-depropyllincomycin in high titers and without lincomycin contamination. Moreover, 4'-pentyl-4'-depropyllincomycin was found to be more active than lincomycin against clinical Staphylococcus isolates with genes determining low-level lincosamide resistance.

• MeSH
• Anti-Bacterial Agents chemistry   metabolism   pharmacology   MeSH
• Bacterial Proteins genetics   metabolism   MeSH
• Humans MeSH
• Lincomycin analogs & derivatives   chemistry   metabolism   pharmacology   MeSH
• Microbial Sensitivity Tests MeSH
• Molecular Structure MeSH
• Proline analogs & derivatives   metabolism   MeSH
• Staphylococcal Infections microbiology   MeSH
• Staphylococcus drug effects   MeSH
• Streptomyces genetics   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Proteins MeSH
• Lincomycin MeSH
• Proline MeSH

Thirty-five Staphylococcus aureus strains from auricular infections were isolated. The identification of strains was confirmed by Api ID 32 Staph strips, the antibiotic susceptibility test was performed using ATB Staph kit. PCR assay was used to detect the oxacillin resistance gene (mecA) and the erythromycin genes (ermA, ermB, ermC, msrA and mef). The susceptibility profile of all strains revealed a low resistance level to oxacillin and erythromycin. The PCR results show that 60 % of the strains are mecA positive. The frequency of erythromycin genes was: ermA (+) 22.8 %, ermB (+) 45.7, ermC (+) 17.1, msrA (+) 28.6. The mef gene was not detected in any strain. No correlations between genotypic and phenotypic methods for the determination of oxacillin and erythromycin resistance was found. However, multiplex PCR technique was shown to be a fast, practical and economic technique for the detection of methicillin-and erythromycin-resistant staphylococci.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Drug Resistance, Bacterial * MeSH
• Bacterial Proteins genetics   metabolism   MeSH
• Erythromycin pharmacology   MeSH
• Humans MeSH
• Membrane Proteins genetics   metabolism   MeSH
• Methyltransferases genetics   metabolism   MeSH
• Oxacillin pharmacology   MeSH
• Polymerase Chain Reaction methods   MeSH
• Penicillin-Binding Proteins MeSH
• Staphylococcal Infections microbiology   MeSH
• Staphylococcus aureus drug effects   genetics   isolation & purification   MeSH
• Ear Auricle microbiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Proteins MeSH
• ErmA protein, Bacteria MeSH Browser
• Erythromycin MeSH
• mecA protein, Staphylococcus aureus MeSH Browser
• MefA protein, Streptococcus MeSH Browser
• Membrane Proteins MeSH
• Methyltransferases MeSH
• Oxacillin MeSH
• Penicillin-Binding Proteins MeSH

Staphylococcal hospital isolates (n = 166) were tested in a touchdown multiplex-polymerase chain reaction assay for the identification of methicillin and mupirocin resistance and discrimination of S. aureus (femA gene) from coagulase negative staphylococci and other bacteria. All isolates harbored the 16SrDNA (Staphylococcus genus specific internal control) gene, and 130 (78 %) the mecA (methicillin resistance) gene. Fifty-seven (44 %) of these were determined as methicillin-resistant S. aureus, while the remaining 73 (56 %) were methicillin-resistant coagulase-negative staphylococci. Seventy-five (45 %) isolates harbored the ileS-2 (high-level mupirocin resistance) gene and were determined as mupirocin-resistant. This assay represents a simple, rapid, reliable approach for the detection and discrimination of methicillin-and mupirocin-resistant staphylococci.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacterial Proteins genetics   metabolism   MeSH
• DNA, Bacterial genetics   MeSH
• Humans MeSH
• Methicillin pharmacology   MeSH
• Drug Resistance, Multiple, Bacterial * MeSH
• Mupirocin pharmacology   MeSH
• Hospitals MeSH
• Polymerase Chain Reaction methods   MeSH
• Methicillin Resistance MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Sensitivity and Specificity MeSH
• Staphylococcal Infections microbiology   MeSH
• Staphylococcus drug effects   genetics   isolation & purification   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Bacterial Proteins MeSH
• DNA, Bacterial MeSH
• Methicillin MeSH
• Mupirocin MeSH
• RNA, Ribosomal, 16S MeSH