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Szemraj M, Glajzner P, Sienkiewicz M. Decreased susceptibility to vancomycin and other mechanisms of resistance to antibiotics in Staphylococcus epidermidis as a therapeutic problem in hospital treatment. Sci Rep 2023; 13:13629. [PMID: 37604965 PMCID: PMC10442409 DOI: 10.1038/s41598-023-40866-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023] Open
Abstract
Multidrug-resistant coagulase-negative staphylococci represent a real therapeutic challenge. The aim of the study was to emphasize the importance of heteroresistance to vancomycin presence in methicillin-resistant strains of S. epidermidis. The research comprised 65 strains of S. epidermidis. Heteroresistance to vancomycin was detected with the use of the agar screening method with Brain Heart Infusion and a population profile analysis (PAP test). In addition, types of cassettes and genes responsible for resistance to antibiotics for 22 multidrug resistant strains were determined. Our investigations showed that 56 of 65 S. epidermidis strains were phenotypically resistant to methicillin. The tested strains were mostly resistant to erythromycin, gentamicin, clindamycin, and ciprofloxacin. Six strains showed decreased susceptibility to vancomycin and their heterogeneous resistance profiles were confirmed with the PAP test. All tested multi-resistant strains exhibited the mecA gene. More than half of them possessed type IV cassettes. ant(4')-Ia and aac(6')/aph(2''), ermC and tetK genes were most commonly found. The described phenomenon of heteroresistance to vancomycin in multidrug resistant bacteria of the Staphylococcus genus effectively inhibits a therapeutic effect of treatment with this antibiotic. That is why it is so important to search for markers that will enable to identify heteroresistance to vancomycin strains under laboratory conditions.
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Affiliation(s)
- Magdalena Szemraj
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Lodz, Lodz, Poland.
| | - Paulina Glajzner
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Lodz, Lodz, Poland
| | - Monika Sienkiewicz
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Lodz, Lodz, Poland
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Martínez-Santos VI, Torres-Añorve DA, Echániz-Aviles G, Parra-Rojas I, Ramírez-Peralta A, Castro-Alarcón N. Characterization of Staphylococcus epidermidis clinical isolates from hospitalized patients with bloodstream infection obtained in two time periods. PeerJ 2022; 10:e14030. [PMID: 36213498 PMCID: PMC9541613 DOI: 10.7717/peerj.14030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/16/2022] [Indexed: 01/19/2023] Open
Abstract
Background In recent years Staphylococcus epidermidis has been considered an important and frequent causative agent of health care-associated infections (HAIs), increasing the costs of hospitalization, morbidity, and mortality. Antibiotic resistance and biofilm formation are the most important obstacles in the treatment of infections caused by this microorganism. The aim of this work was to determine the most prevalent STs, as well as the antibiotic resistance profile and biofilm formation of S. epidermidis clinical isolates obtained from hospitalized patients in two hospitals in Acapulco, Guerrero in two time periods. Methods Twenty methicillin-resistant S. epidermidis strains isolated from patients with bacteremia in two hospitals in two time periods were analyzed. Identification and antibiotic susceptibility were performed using the Vitek automated system. Molecular confirmation of the identification and methicillin resistance was performed by duplex PCR of the mecA and nuc genes. Biofilm production was analyzed, and the clonal origin was determined by multilocus sequence typing (MLST). Results We identified 14 antibiotic resistance profiles as well as 13 sequence types (ST), including the new ST761. We also found that ST2 and ST23 were the most prevalent and, together with ST59, were found in both time periods. Seventeen of our clinical isolates were multidrug-resistant, but all of them were sensitive to linezolid and vancomycin, and this was not related to biofilm production. Additionally, we standardized a duplex PCR to identify methicillin-resistant S. epidermidis strains. In conclusion, S. epidermidis STs 2, 23, and 59 were found in both time periods. This study is the first report of S. epidermidis ST761. The clinical isolates obtained in this work showed a high multidrug resistance that is apparently not related to biofilm production.
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Affiliation(s)
| | - David A. Torres-Añorve
- Laboratorio de Investigación en Microbiología, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, Mexico
| | - Gabriela Echániz-Aviles
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Isela Parra-Rojas
- Labotatorio de Investigación en Obesidad y Diabetes, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, Mexico
| | - Arturo Ramírez-Peralta
- Laboratorio de Investigación en Patometabolismo Microbiano, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, Mexico
| | - Natividad Castro-Alarcón
- Laboratorio de Investigación en Microbiología, Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Guerrero, Chilpancingo, Guerrero, Mexico
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Szemraj M, Czekaj T, Kalisz J, Szewczyk EM. Differences in distribution of MLS antibiotics resistance genes in clinical isolates of staphylococci belonging to species: S. epidermidis, S. hominis, S. haemolyticus, S. simulans and S. warneri. BMC Microbiol 2019; 19:124. [PMID: 31182020 PMCID: PMC6558908 DOI: 10.1186/s12866-019-1496-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 05/29/2019] [Indexed: 11/10/2022] Open
Abstract
Background Macrolides and lincosamides are two leading types of antibiotics commonly used in therapies. The study examines the differences in resistance to these antibiotics and their molecular bases in S. epidermidis as well as in rarely isolated species of coagulase-negative staphylococci such as S. hominis, S. haemolyticus, S. warneri and S. simulans. The isolates were tested for the presence of the erm(A), erm(B), erm(C), lnu(A), msr(A), msr(B), mph(C), ere(A) and ere(B) genes. Phenotypic resistance to methicillin and mecA presence were also determined. Results The MLSB resistance mechanism was phenotypically found in isolates of species included in the study. The most prevalent MLSB resistance mechanism was observed in S. hominis, S. haemolyticus and S. epidermidis isolates mainly of the MLSB resistance constitutive type. Macrolide, lincosamide and streptogramin B resistance genes were rarely detected in isolates individually. The erm(B), ere(A) and ere(B) genes were not found in any of the strains. The erm(A) gene was determined only in four strains of S. epidermidis and S. hominis while lnu(A) was seen in eight strains (mainly in S. hominis). The erm(C) gene was present in most of S. epidermidis strains and predominant in S. hominis and S. simulans isolates. The examined species clearly differed between one another in the repertoire of accumulated genes. Conclusions The presence of genes encoding the MLSB resistance among CoNS strains demonstrates these genes’ widespread prevalence and accumulation in opportunistic pathogens that might become gene reservoir for bacteria with superior pathogenic potential.
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Affiliation(s)
- Magdalena Szemraj
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Łódź, Pomorska 137, 90-235, Łódź, Poland.
| | - Tomasz Czekaj
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Łódź, Pomorska 137, 90-235, Łódź, Poland
| | - Jacek Kalisz
- Synevo Sp. z o. o., Microbiological Laboratory of Łódź, Sokola 14, 93-519, Łódź, Poland
| | - Eligia M Szewczyk
- Department of Pharmaceutical Microbiology and Microbiological Diagnostic, Medical University of Łódź, Pomorska 137, 90-235, Łódź, Poland
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Khashei R, Malekzadegan Y, Sedigh Ebrahim-Saraie H, Razavi Z. Phenotypic and genotypic characterization of macrolide, lincosamide and streptogramin B resistance among clinical isolates of staphylococci in southwest of Iran. BMC Res Notes 2018; 11:711. [PMID: 30305181 PMCID: PMC6180372 DOI: 10.1186/s13104-018-3817-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/03/2018] [Indexed: 01/22/2023] Open
Abstract
Objective The present study aimed to determine the phenotypic and genotypic profile of macrolide, lincosamide and streptogramin B (MLSB) resistance in clinical isolates of staphylococci. Results This cross-sectional study was conducted on 164 non-duplicated staphylococci isolates collected during August 2015 to February 2016 from two tertiary care hospitals in Shiraz, southwest of Iran. Of the 164 isolates, 86 erythromycin-resistant isolates consist of 35 Staphylococcus aureus and 51 coagulase negative staphylococci (CoNS) were included in the study. Of the 35 S. aureus, the prevalence of cMLS (constitutive), iMLS (inducible), and MS phenotypes were found 82.9%, 8.6% and 8.6%, respectively. Among 51 CoNS, the frequencies of cMLS, iMLS, and MS phenotypes were detected 66.7%, 11.8% and 21.6%, respectively. Among S. aureus isolates, the predominant genes were ermC in 82.9% isolates, followed by ermA in 57.1% and msrA in 28.6% of isolates. Among CoNS isolates, the most frequent genes were diagnosed ermC in 70.6% isolates followed by msrA in 68.6% and ermA in 11.8% of isolates. In conclusion, regarding the presence of MLSB resistance in our region, diagnosis of this resistance type on a routine basis in staphylococcal clinical isolates is of particular importance.
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Affiliation(s)
- Reza Khashei
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Yalda Malekzadegan
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hadi Sedigh Ebrahim-Saraie
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Razavi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
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Różańska A, Chmielarczyk A, Romaniszyn D, Bulanda M, Walkowicz M, Osuch P, Knych T. Antibiotic resistance, ability to form biofilm and susceptibility to copper alloys of selected staphylococcal strains isolated from touch surfaces in Polish hospital wards. Antimicrob Resist Infect Control 2017; 6:80. [PMID: 28815023 PMCID: PMC5556671 DOI: 10.1186/s13756-017-0240-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/04/2017] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Despite the employment of sanitary regimes, contact transmission of the aetiological agents of hospital infections is still exceedingly common. The issue of microbe transmission becomes particularly important when facing multidrug-resistant microorganisms such as methicillin-resistant staphylococci. In the case of deficiencies in cleaning and disinfection procedures, hospital equipment made of copper alloys can play an important role, complementing traditional hospital hygiene procedures. The objective of this study was to characterize staphylococcal strains isolated from touch surfaces in Polish hospital wards in terms of their drug resistance, ability to form biofilm and susceptibility to antimicrobial activity of copper alloys. METHODS The materials for the study were 95 staphylococcal strains isolated from touch surfaces in 13 different hospital wards from Małopolska province (the south of Poland). Phenotypic and genotypic antibiotic resistance were checked for erythromycin, clindamycin, gentamycin, ciprofloxacin, trimethoprim/sulfamethoxazole and mupirocin. Biofilm formation ability for the tested strains was checked with the use of culture on Congo red agar. Susceptibility to copper, tin bronze, brass and new silver was tested using a modification of the Japanese standard. RESULTS Over 67% of the analysed staphylococcal strains were methicillin-resistant (MR). Four strains were resistant to all of the tested antibiotics, and 14 were resistant to all except mupirocin. Strains classified as MR had significantly increased resistance to the remaining antibiotic groups. About one-third of the analysed strains revealed biofilm-forming ability. Among the majority of species, biofilm-forming and non-biofilm-forming strains were distributed evenly; in the case of S. haemolyticus only, negative strains accounted for 92.8%. Susceptibility to copper alloys was different between strains and rather lower than in the case of the SA strain selected for comparison. CONCLUSIONS Coagulase-negative staphylococci, the most commonly isolated in Polish hospital wards, should not be neglected as an infection risk factor due their high antibiotic resistance. Our experiments confirmed that touch surfaces made of copper alloys may play an important role in eliminating bacteria from the hospital environment.
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Affiliation(s)
- Anna Różańska
- Jagiellonian University Medical College, Faculty of Medicine, Chair of Microbiology, Czysta str. 18, 31-121 Kraków, Poland
| | - Agnieszka Chmielarczyk
- Jagiellonian University Medical College, Faculty of Medicine, Chair of Microbiology, Czysta str. 18, 31-121 Kraków, Poland
| | - Dorota Romaniszyn
- Jagiellonian University Medical College, Faculty of Medicine, Chair of Microbiology, Czysta str. 18, 31-121 Kraków, Poland
| | - Małgorzata Bulanda
- Jagiellonian University Medical College, Faculty of Medicine, Chair of Microbiology, Czysta str. 18, 31-121 Kraków, Poland
| | - Monika Walkowicz
- Faculty of Non-Ferrous Metals, Department of Metal Working and Physical Metallurgy of Non-Ferrous Metals, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
| | - Piotr Osuch
- Faculty of Non-Ferrous Metals, Department of Metal Working and Physical Metallurgy of Non-Ferrous Metals, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
| | - Tadeusz Knych
- Faculty of Non-Ferrous Metals, Department of Metal Working and Physical Metallurgy of Non-Ferrous Metals, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
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Lenart-Boroń A, Wolny-Koładka K, Juraszek K, Kasprowicz A. Phenotypic and molecular assessment of antimicrobial resistance profile of airborne Staphylococcus spp. isolated from flats in Kraków. AEROBIOLOGIA 2017; 33:435-444. [PMID: 28955110 PMCID: PMC5591801 DOI: 10.1007/s10453-017-9481-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 04/04/2017] [Indexed: 05/25/2023]
Abstract
Bacteria of the genus Staphylococcus were isolated from air sampled from living spaces in Kraków (Poland). In total, 55 strains belonging to the genus Staphylococcus were isolated from 45 sites, and 13 species of coagulase-negative staphylococci were identified. The species composition of studied airborne microbiota contains Staphylococcus species that are rarely infectious to humans. Most commonly isolated species comprised S. hominis and S. warneri. The disk-diffusion tests showed that the collected isolates were most frequently resistant to erythromycin. The PCR technique was employed to search for genes conferring the resistance in staphylococci to antibiotics from the group of macrolides, lincosamides and streptogramins. The analyzed Staphylococcus isolates possessed simultaneously 4 different resistance genes. The molecular analysis with the use of specific primers allowed to determine the most prevalent gene which is mphC, responsible for the resistance to macrolides and for the enzymatic inactivation of the drug by phosphotransferase. The second most often detected gene was msrA1, which confers the resistance of staphylococci to macrolides and is responsible for active pumping of antimicrobial particles out of bacterial cells.
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Affiliation(s)
- Anna Lenart-Boroń
- Department of Microbiology, University of Agriculture, Mickiewicza Ave. 24/28, 31-059 Kraków, Poland
| | - Katarzyna Wolny-Koładka
- Department of Microbiology, University of Agriculture, Mickiewicza Ave. 24/28, 31-059 Kraków, Poland
| | - Katarzyna Juraszek
- Faculty of Biotechnology and Horticulture, University of Agriculture, 29 Listopada Ave 54, 31-425 Kraków, Poland
| | - Andrzej Kasprowicz
- Centre for Microbiological Research and Autovaccines, Sławkowska 17, 31-016 Kraków, Poland
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Fyfe C, Grossman TH, Kerstein K, Sutcliffe J. Resistance to Macrolide Antibiotics in Public Health Pathogens. Cold Spring Harb Perspect Med 2016; 6:a025395. [PMID: 27527699 PMCID: PMC5046686 DOI: 10.1101/cshperspect.a025395] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Macrolide resistance mechanisms can be target-based with a change in a 23S ribosomal RNA (rRNA) residue or a mutation in ribosomal protein L4 or L22 affecting the ribosome's interaction with the antibiotic. Alternatively, mono- or dimethylation of A2058 in domain V of the 23S rRNA by an acquired rRNA methyltransferase, the product of an erm (erythromycin ribosome methylation) gene, can interfere with antibiotic binding. Acquired genes encoding efflux pumps, most predominantly mef(A) + msr(D) in pneumococci/streptococci and msr(A/B) in staphylococci, also mediate resistance. Drug-inactivating mechanisms include phosphorylation of the 2'-hydroxyl of the amino sugar found at position C5 by phosphotransferases and hydrolysis of the macrocyclic lactone by esterases. These acquired genes are regulated by either translation or transcription attenuation, largely because cells are less fit when these genes, especially the rRNA methyltransferases, are highly induced or constitutively expressed. The induction of gene expression is cleverly tied to the mechanism of action of macrolides, relying on antibiotic-bound ribosomes stalled at specific sequences of nascent polypeptides to promote transcription or translation of downstream sequences.
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Affiliation(s)
- Corey Fyfe
- Tetraphase Pharmaceuticals, Watertown, Massachusetts 02472
| | | | - Kathy Kerstein
- Tetraphase Pharmaceuticals, Watertown, Massachusetts 02472
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Lenart-Boroń A, Wolny-Koładka K, Stec J, Kasprowic A. Phenotypic and Molecular Antibiotic Resistance Determination of Airborne Coagulase NegativeStaphylococcusspp. Strains from Healthcare Facilities in Southern Poland. Microb Drug Resist 2016; 22:515-522. [DOI: 10.1089/mdr.2015.0271] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Anna Lenart-Boroń
- Department of Microbiology, University of Agriculture, Kraków, Poland
| | | | - Joanna Stec
- Department of Microbiology, University of Agriculture, Kraków, Poland
| | - Andrzej Kasprowic
- Centre for Microbiological Research and Autovaccines, Kraków, Poland
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Juda M, Chudzik-Rzad B, Malm A. The prevalence of genotypes that determine resistance to macrolides, lincosamides, and streptogramins B compared with spiramycin susceptibility among erythromycin-resistant Staphylococcus epidermidis. Mem Inst Oswaldo Cruz 2016; 111:155-60. [PMID: 27008373 PMCID: PMC4804497 DOI: 10.1590/0074-02760150356] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/15/2016] [Indexed: 12/02/2022] Open
Abstract
Coagulase-negative staphylococci, particularly Staphylococcus
epidermidis, can be regarded as potential reservoirs of resistance genes
for pathogenic strains, e.g., Staphylococcus aureus. The aim of this
study was to assess the prevalence of different resistance phenotypes to macrolide,
lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant
S. epidermidis, together with the evaluation of genes promoting
the following different types of MLSB resistance:ermA,
ermB, ermC,msrA,
mphC, and linA/A’. Susceptibility to spiramycin
was also examined. Among 75 erythromycin-resistantS. epidermidis
isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and
constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the
majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas
strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of
inhibition around the clindamycin disc near the spiramycin disc was found for some
spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of
resistance to clindamycin by this 16-membered macrolide. The most frequently isolated
gene was ermC, irrespective of the MLSB resistance phenotype,
whereas the most often noted gene combination wasermC,
mphC, linA/A’. The results obtained showed that
the genes responsible for different mechanisms of MLSB resistance in S.
epidermidis generally coexist, often without the phenotypic expression of
each of them.
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Affiliation(s)
- Marek Juda
- Department of Pharmaceutical Microbiology, Medical University of Lublin, Lublin, Poland
| | - Beata Chudzik-Rzad
- Department of Pharmaceutical Microbiology, Medical University of Lublin, Lublin, Poland
| | - Anna Malm
- Department of Pharmaceutical Microbiology, Medical University of Lublin, Lublin, Poland
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Mesbah Elkammoshi A, Ghasemzadeh-Moghaddam H, Amin Nordin S, Mohd Taib N, Kumar Subbiah S, Neela V, Awang Hamat R. A Low Prevalence of Inducible Macrolide, Lincosamide, and Streptogramin B Resistance Phenotype among Methicillin-Susceptible Staphylococcus aureus Isolated from Malaysian Patients and Healthy Individuals. Jundishapur J Microbiol 2016; 9:e37148. [PMID: 27942364 PMCID: PMC5136447 DOI: 10.5812/jjm.37148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 08/24/2016] [Accepted: 09/05/2016] [Indexed: 01/14/2023] Open
Abstract
Background Antibiotic resistance among Staphylococcus aureus is of great concern worldwide. This resistance is further complicated by the ability of S. aureus to confer cross-resistance to other antibiotics due to the presence of resistance genes, such as erythromycin resistance methylase (erm) genes, which render the bacterium resistant to macrolide-lincosamide-streptogramin B (MLSB) antibiotics. Resistance to these antibiotics can lead to therapeutic failure, resulting in significant morbidity and mortality in patients with S. aureus infections. Objectives This study was performed to examine the distribution of MLSB-resistant strains of methicillin-susceptible S. aureus (MSSA), which were obtained from hospitalized patients and normal healthy individuals (carriers) using phenotypic methods, such as the double-disk diffusion (D-test) and the genotypic method by polymerase chain reaction (PCR). Methods A total of 183 nonduplicative MSSA isolates obtained from hospitalized patients (133) and carriers (50) in our previous studies were randomly selected for the D-test. The guidelines of the Clinical and Laboratory Standards Institute (CLSI) were used for the interpretation of the results of this test. The detection of ermA, ermB, ermC and msrA genes by PCR was performed for isolates that had positive D-test results and that were resistant to erythromycin. Results Of the 183 MSSA isolates, 97.2% and 98.4% were highly susceptible to erythromycin and clindamycin, respectively. MSLB resistance was detected in four isolates (2.2%). Of the 133 MSSA isolated from hospitalized patients, only 3.0% (4/133) and 2.3% (3/133) exhibited resistance to erythromycin and clindamycin, respectively. With regard to the MLSB resistance phenotypes, only 1.6% and 0.6% exhibited inducible MLSB (iMLSB) and MS phenotypes, respectively. The ermC gene was detected in all three iMLSB phenotypes, and the msrA gene was detected in the MS phenotype. Surprisingly, all MSSA isolates (100%) from carriers exhibited extremely high susceptibility to both antibiotics. Conclusions The prevalence rates of iMLSB MSSA isolates vary according to geographical locations and the local antibiotic policy. The low prevalence rate of iMLSB MSSA isolates could probably be related to the judicious use of antibiotics for treating S. aureus infections in our studied population. Nonetheless, continuous antibiotic surveillance is still necessary to control any emergence of resistance isolates so that targeted therapy and effective control can be implemented accordingly.
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Affiliation(s)
- Asma Mesbah Elkammoshi
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
| | - Hamed Ghasemzadeh-Moghaddam
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
- Faculty of Medicine, North Khorasan University of Medical Sciences, Bojnurd, IR Iran
| | - Syafinaz Amin Nordin
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
| | - Niazlin Mohd Taib
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
| | - Suresh Kumar Subbiah
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
| | - Vasanthakumari Neela
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
| | - Rukman Awang Hamat
- Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universit Putra Malaysia, Serdang, Selangor, Malaysia
- Corresponding author: Rukman Awang Hamat, Faculty of Medicine and Health Sciences, Department of Medical Microbiology and Parasitology, Universiti Putra Malaysia, P.O. Box: 43400, Serdang, Selangor, Malaysia. Tel: +603-89472365, Fax: +603-86413802, E-mail:
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