Abstract
A high rate of infections with methicillin-resistant Staphylococcus aureus (MRSA) has been documented, in both hospital- (HA-MRSA) and community-acquired (CA-MRSA) diseases in Jordan. Erythromycin and clindamycin are considered treatments of choice. However, resistance to erythromycin with false susceptibility to clindamycin in vitro may lead to therapeutic failure. Hence, it is mandatory to study the prevalence of inducible resistance to macrolide-lincosamide-streptogramin B (iMLSB) antibiotics conferred by erm genes in those bacteria. S. aureus isolates were identified morphologically and biochemically, and MRSA were appraised using standard procedures. Induction in resistance to MLSB antibiotics among MRSA isolates was detected phenotypically using the D-test, and the presence of erm genes was revealed by polymerase chain reaction (PCR). Of 126 collected Staphylococcus isolates, 71 (56.3%) isolates were S. aureus, of which 55 (77.5%) were MRSA. A total of 43 (78.2%) MRSA-discordant isolates were resistant to erythromycin, of which 33 (76.7%) exhibited the iMLSB (D-test positive), 2 (4.7%) the MSB (D-test negative), and 8 (18.6%) the constitutive resistant (cMLSB) phenotypes. Induction of clindamycin resistance was 1.6 times greater in CA-MRSA than in HA-MRSA. Furthermore, ermA and ermC were significantly prevalent in HA-MRSA and CA-MRSA, respectively. Continuous surveillance of the MLSB resistance is important and required before the prescription of clindamycin to treat MRSA infections.
Highlights
A high rate of infections with methicillin-resistant Staphylococcus aureus (MRSA) has been documented, in both hospital- (HAMRSA) and community-acquired (CA-MRSA) diseases in Jordan
MRSA infections are treated with macrolidelincosamide-streptogramin B (MLSB) antibiotics, with clindamycin as the drug of choice due to its pharmacokinetic properties [2]
Three MLSB phenotypes are known in S. aureus, a constitutive resistant phenotype, a clindamycin-susceptible phenotype in vitro with inducible resistance in vivo, and a clindamycin-susceptible and macrolide-steptogramin B-resistant phenotype (MSB)
Summary
In Jordan, methicillin-resistant Staphylococcus aureus (MRSA) represents 57%–62% and 19% of clinical and nasal carriage isolates, respectively [1]. As the first study in Jordan to our best knowledge, this study reports the prevalence of iMLSB, cMLSB, and MS phenotypes with detection of erm genes in clinical and nasal carriage MRSA isolates. Multiplex PCR: A total volume of 20 μL containing 10 μL of Initial denaturation step of 5 min at 95°C, followed by master mix, 100 ng of template DNA, 6 μL of primer mixture (10 35 cycles at 95°C for 30 s of denaturation, 1 min of annealing at pmol/μL, Midland Company, Midland, USA), and nucleic acid 54°C, 1 min of elongation at 72°C, and a final extension step of 5 free water. Erm: erythromycin ribosomal methylase encoding gene; mec: methicillin resistance coding gene; sau: Staphylococcus aureus specific gene. Bp: base pair; erm: erythromycin ribosomal methylase encoding gene; mec: methicillin resistance coding gene; sau: Staphylococcus aureus specific gene. ErmB was detected at relatively high frequency in both HA-MRSA and CA-MRSA (56.3% and 58.8%, respectively)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
