High prevalence of inducible clindamycin resistance among Staphylococcus aureus isolates from patients with cystic fibrosis

Prevalence of antibiotic resistance of Staphylococcus aureus in cystic fibrosis infection: a systematic review and meta-analysis

OBJECTIVES

Cystic fibrosis (CF) is a hereditary recessive disease that affects the mucous clearance of the lungs and allows bacteria such as Staphylococcus aureus to settle in the lung and cause infection. This study examined the prevalence of antibiotic resistance of S. aureus in cystic fibrosis infection using a systematic review and meta-analysis.

METHODS

A comprehensive and systematic search of related articles was conducted through the PubMed, Scopus, and Web of Science databases until March 2022. The weighted pooled resistance rate of antibiotics was analysed with Freeman-Tukey double arcsine transformation in the Stata software version 17.1 using the Metaprop command.

RESULTS

In this meta-analysis, 25 studies were used based on criteria to evaluate the pattern of S. aureus resistance in CF. Vancomycin and teicoplanin were the most effective options for treatment of CF patients; the highest level of antibiotic resistance observed was to erythromycin and clindamycin.

CONCLUSION

High levels of resistance to most of the antibiotics studied was observed. The high levels of antibiotic resistance observed are worrisome and indicate the need to monitor antibiotic use.

State of the art in cystic fibrosis pharmacology optimization of antimicrobials in the treatment of cystic fibrosis pulmonary exacerbations: III. Executive summary

Acute pulmonary exacerbations are complications of cystic fibrosis (CF) and are associated with increased morbidity and mortality. Methicillin-resistant Staphylococcus aureus (MRSA) and Aspergillus fumigatus are organisms that have been detected in the lungs of CF patients. The focus of this review is to provide an overview of the classes of antimicrobials used for MRSA and allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity reaction caused by A. fumigatus. The current anti-MRSA antibiotics and medications for ABPA dosing recommendations are discussed. This article also reviews the findings from the MRSA utilization surveys and the pharmacokinetic and pharmacodynamic differences between CF and non-CF patients. Antimethicillin S. aureus antibiotics include ceftaroline, clindamycin, fluoroquinolone derivatives (ciprofloxacin, levofloxacin), glycopeptide derivatives (telavancin, vancomycin), linezolid, rifampin, sulfamethoxazole/trimethoprim, and tetracycline derivatives (doxycycline, minocycline, tigecycline). Medications used for ABPA include corticosteroids, amphotericin B, azole antifungals (isavuconazole, itraconazole, posaconazole, voriconazole), and a monoclonal antibody, omalizumab.

State of the art in cystic fibrosis pharmacology-Optimization of antimicrobials in the treatment of cystic fibrosis pulmonary exacerbations: I. Anti-methicillin-resistant Staphylococcus aureus (MRSA) antibiotics

Acute pulmonary exacerbations (APE) are a complication of cystic fibrosis (CF) and are associated with morbidity and mortality. Methicillin-resistant Staphylococcus aureus (MRSA) is one of many organisms that has been detected in the airways of patients with CF. This review provides an evidence-based summary of pharmacokinetic/pharmacodynamic (PK/PD), tolerability, and efficacy studies utilizing anti-MRSA antibiotics (ie, ceftaroline, clindamycin, fluoroquinolone derivatives (ciprofloxacin, levofloxacin), glycopeptide derivatives (telavancin, vancomycin), linezolid, rifampin, sulfamethoxazole/trimethoprim (SMZ/TMP), and tetracycline derivatives (doxycycline, minocycline, tigecycline) in the treatment of APE and identifies areas where further study is warranted. A recent utilization study of antimicrobials for anti-MRSA has shown some CF Foundation accredited care centers and affiliate programs are using doses higher than the FDA-approved doses. Further studies are needed to determine the PK/PD properties in CF patients with clindamycin, minocycline, rifampin, SMZ/TMP, telavancin, and tigecycline; as well as, efficacy and tolerability studies with ciprofloxacin, clindamycin, doxycycline, levofloxacin, minocycline, rifampin, SMZ/TMP, in CF patients with MRSA.

Antimicrobial Treatment of Staphylococcus aureus in Patients With Cystic Fibrosis

Staphylococcus aureus is a ubiquitous human commensal pathogen. It is commonly isolated in cystic fibrosis (CF) patients and is considered one of the main causes of the recurrent acute pulmonary infections and progressive decline in lung function that characterize this inherited life-threatening multisystem disorder. However, the true role of S. aureus in CF patients is not completely understood. The main aim of this narrative review is to discuss the present knowledge of the role of S. aureus in CF patients. Literature review showed that despite the fact that the availability and use of drugs effective against S. aureus have coincided with a significant improvement in the prognosis of lung disease in CF patients, clearly evidencing the importance of S. aureus therapy, how to use old and new drugs to obtain the maximal effectiveness has not been precisely defined. The most important problem remains that the high frequency with which S. aureus is carried in healthy subjects prevents the differentiation of simple colonization from infection. Moreover, although experts recommend antibiotic administration in CF patients with symptoms and in those with persistent detection of S. aureus, the best antibiotic approach has not been defined. All these problems are complicated by the evidence that the most effective antibiotic against methicillin-resistant S. aureus (MRSA) cannot be used in patients with CF with the same schedules used in patients without CF. Further studies are needed to solve these problems and to assure CF patients the highest level of care.

Antibiotic Management of Methicillin-Resistant Staphylococcus aureus–Associated Acute Pulmonary Exacerbations in Cystic Fibrosis

Objective: To review the treatment of methicillin-resistant Staphylococcus aureus (MRSA)–associated acute pulmonary exacerbations (APEs) in cystic fibrosis (CF). Data Sources: A search of PubMed, MEDLINE, Cochrane Library and Clinicaltrials.gov databases through November 2014 was conducted using the search terms Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, pulmonary exacerbations, and cystic fibrosis. Study Selection and Data Extraction: All English-language research articles, case reports, and case series were evaluated. A total of 185 articles were identified related to MRSA and CF; 30 articles that studied treatments of MRSA APE in CF were included. Data Synthesis: The persistent presence of MRSA in the respiratory tract of patients with CF has been associated with higher morbidity and an increased risk of death. Limited clinical data exist supporting the efficacy of any specific antimicrobial currently available for the treatment of APE secondary to MRSA. Conclusions: Data extrapolated from other populations suggest that vancomycin and linezolid are appropriate first-line treatment options for the treatment of APE secondary to MRSA. Second-line options include doxycycline or minocycline and trimethoprim/sulfamethoxazole, each of which may be useful in patients coinfected with other respiratory pathogens, for which they may provide overlapping coverage. Ceftaroline and ceftobiprole are newer antibiotics that appear to have a potential role in the treatment of APE in CF, but the latter is not currently available to the US market. Although potentially useful, clindamycin is limited by high rates of resistance, telavancin is limited by its toxicity profile, and tigecycline is limited by a lack of demonstrated efficacy for infections that are similar to that seen in the CF population. Studies investigating the clinical utility of the above-cited antibiotics for APE in CF secondary to MRSA are desperately needed to broaden the treatment armamentarium for this medical condition.

Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic

Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.

Performance of an agar dilution method and a Vitek 2 card for detection of inducible clindamycin resistance in Staphylococcus spp

The D-zone test detects inducible clindamycin resistance in Staphylococcus spp. Two other methods not described by the Clinical and Laboratory Standards Institute (CLSI) are available to test for this resistance mechanism: an agar dilution method and new Vitek 2 cards. This study evaluated the performance of both methods in detecting inducible clindamycin resistance. Nonduplicate clinical strains of Staphylococcus spp. (111 Staphylococcus aureus and 52 coagulase-negative staphylococcus strains), intermediate or resistant to erythromycin but susceptible to clindamycin, were obtained from three hospitals in Montreal, Quebec, Canada. Molecular analysis to detect resistance genes was conducted on all strains. A Mueller-Hinton agar containing 1 mg of erythromycin and 0.5 mg of clindamycin/liter was used for the dilution method, and two inocula were tested: 10(4) and 10(5) CFU per spot. Plates were read at 24 and 48 h. The Vitek 2 AST-P580 card was used according to the manufacturer's recommendations. The results were compared to those of the D-zone test. The D-zone test was positive in 134 of 163 (82%) strains. With the 10(4) CFU inoculum, the sensitivities were 84 and 99% at 24 and 48 h, respectively. The 10(5) CFU inoculum increased the sensitivities at 24 and 48 h to 91 and 100%, respectively. The specificity was 100% for the 10(4) CFU inoculum at 24 h and 97% for the other combinations. The sensitivity and specificity for the Vitek 2 card were 93 and 100%, respectively. The performance of both the agar dilution method and the Vitek 2 card was good, but these methods were not as sensitive as the D-zone test at 24 h.

Update on cutaneous manifestations of infectious diseases

Many emerging pathogens present in the skin and are of interest to dermatologists. Recent epidemics of measles, avian flu, and SARS demonstrated how an organism can rapidly spread worldwide because of airline travel. Travelers are often contagious before they are aware that they have the disease, contributing to the spread. This article reviews bacterial, mycobacterial, fungal, and viral pathogens important to dermatologists.

Genomic analysis of an emerging multiresistant Staphylococcus aureus strain rapidly spreading in cystic fibrosis patients revealed the presence of an antibiotic inducible bacteriophage

Background

Staphylococcus aureus is a major human pathogen responsible for a variety of nosocomial and community-acquired infections. Recent reports show that the prevalence of Methicillin-Resistant S. aureus (MRSA) infections in cystic fibrosis (CF) patients is increasing. In 2006 in Marseille, France, we have detected an atypical MRSA strain with a specific antibiotic susceptibility profile and a unique growth phenotype. Because of the clinical importance of the spread of such strain among CF patients we decided to sequence the genome of one representative isolate (strain CF-Marseille) to compare this to the published genome sequences. We also conducted a retrospective epidemiological analysis on all S. aureus isolated from 2002 to 2007 in CF patients from our institution.

Results

CF-Marseille is multidrug resistant, has a hetero-Glycopeptide-Intermediate resistance S. aureus phenotype, grows on Cepacia agar with intense orange pigmentation and has a thickened cell wall. Phylogenetic analyses using Complete Genome Hybridization and Multi Locus VNTR Assay showed that CF-Marseille was closely related to strain Mu50, representing vancomycin-resistant S. aureus. Analysis of CF-Marseille shows a similar core genome to that of previously sequenced MRSA strains but with a different genomic organization due to the presence of specific mobile genetic elements i.e. a new SCCmec type IV mosaic cassette that has integrated the pUB110 plasmid, and a new phage closely related to phiETA3. Moreover this phage could be seen by electron microscopy when mobilized with several antibiotics commonly used in CF patients including, tobramycin, ciprofloxacin, cotrimoxazole, or imipenem. Phylogenetic analysis of phenotypically similar h-GISA in our study also suggests that CF patients are colonized by polyclonal populations of MRSA that represents an incredible reservoir for lateral gene transfer.

Conclusion

In conclusion, we demonstrated the emergence and spreading of a new isolate of MRSA in CF patients in Marseille, France, that has probably been selected in the airways by antibiotic pressure. Antibiotic-mediated phage induction may result in high-frequency transfer and the unintended consequence of promoting the spread of virulence and/or antibiotic resistance determinants. The emergence of well-adapted MRSA is worrying in such population chronically colonized and receiving many antibiotics and represents a model for emergence of uncontrollable super bugs in a specific niche.

Reviewers

This article was reviewed by Eric Bapteste, Pierre Pontarotti, and Igor Zhulin. For the full reviews, please go to the Reviewers' comments section.