Higher mortality rates associated with Clostridioides difficile infection in hospitalized children with cystic fibrosis

OBJECTIVE(S)

To determine the association of Clostridioides difficile Infection (CDI) with in-hospital mortality, Length of Stay (LOS), and hospital charges among pediatric Cystic Fibrosis (CF) hospitalizations using a large nationally representative pediatric hospital database.

STUDY DESIGN

We identified Cystic Fibrosis-related hospitalizations during the years 1997 to 2016 in the Kids' Inpatient Database (KID) and compared in-hospital mortality, LOS, and hospital charges among hospitalizations with and without a coexisting diagnosis of C. difficile using logistic regression models for mortality and general linear models with gamma distribution and logarithmic transformation for LOS and hospital charges. We also evaluated temporal trends in the proportion of CF hospitalizations with concomitant CDI using data published triennially RESULTS: We analyzed 21,616 pediatric CF hospitalizations between the years 1997 to 2016 and found a total of 240 (1.1%) hospitalizations with concurrent CDI diagnosis. Adjusted analyses demonstrated an association of CDI with increased mortality (OR 5.2, 95% CI 2.5-10.7), longer LOS (46.5% increment, 95% CI 36.0-57.1), and higher charges (65.8% increment, 95% CI 53.5-78.1) for all comparisons. The proportion of CF hospitalizations with CDI increased over time from 0.64% in 1997 to 1.73% in 2016 (p < 0.001).

CONCLUSION(S)

As CDI is associated with excess mortality, LOS, and cost in children hospitalized for CF, a healthy level of suspicion for CDI may be needed in patients with CF in the appropriate clinical context. Efforts to prevent, diagnose, and treat CDI may improve hospital outcomes among children with CF.

Review on Stenotrophomonas maltophilia: an emerging multidrug-resistant opportunistic pathogen

Stenotrophomonas maltophilia is an opportunistic pathogen that results in nosocomial infections in immunocompromised individuals. These bacteria colonize on the surface of medical devices and therapeutic equipment like urinary catheters, endoscopes, and ventilators, causing respiratory and urinary tract infections. The low outer membrane permeability of multidrug-resistance efflux systems and the two chromosomally encoded β-lactamases present in S.maltophilia are challenging for arsenal control. The cell-associated and extracellular virulence factors in S.maltophilia are involved in colonization and biofilm formation on the host surfaces. The spread of antibiotic-resistant genes in the pathogenic S.maltophilia attributes to bacterial resistance against a wide range of antibiotics, including penicillin, quinolones, and carbapenems. So far, tetracycline derivatives, fluoroquinolones, and trimethoprim-sulfamethoxazole (TMP-SMX) are considered promising antibiotics against S.maltophilia. Due to the adaptive nature of the intrinsically resistant mechanism towards the number of antibiotics and its ability to acquire new resistance via mutation and horizontal gene transfer, it is quite tricky for medicinal contribution against S.maltophilia. The current review summarizes the literary data of pathogenicity, quorum sensing, biofilm formation, virulence factors, and antibiotic resistance of S.maltophilia.

Safety of high-dose doripenem in adult patients with cystic fibrosis

BACKGROUND

High doses of β-lactam antibiotics have been advocated for acute pulmonary exacerbations caused by Pseudomonas aeruginosa in patients with cystic fibrosis (CF) secondary to high minimum inhibitory concentrations (MIC) of the infecting organisms. Some β-lactam antibiotics have increased elimination in CF patients. This case series examines the safety of high-dose doripenem (HDD), 2 g intravenously every 8 hours, which is 4 times the labeled dose, in CF patients.

METHODS

This was a retrospective, single site, chart review of all CF patients given HDD during a 3-year period. Adverse events were prospectively defined using labeled definitions within the package insert and the medical literature. A standard case report form was used to collect demographic details, antibiotic lengths of therapy and adverse events.

RESULTS

A total of 17 patients (9 males), with a median age of 24 years, contributed 43 unique visits and 382 HDD exposure days. Mean duration of inpatient doripenem use was 8.9 days. Concurrent antibiotics were common, with a median number of additional antibiotics per admission of three. The median number of adverse effects documented was two. The most common adverse event was anemia, which was identified in 41 of 43 visits, but was present on admission in 31 instances. One patient developed leukopenia for 1 day, but returned to normal without dose adjustment. There were three instances of Clostridium difficile infection. One patient was documented to have an allergic reaction that led to discontinuation, but was ultimately rechallenged without adverse effect. Other common adverse events were gastrointestinal in origin. No other possible adverse effects led to discontinuation of the drug.

CONCLUSIONS

In adult patients with CF, HDD in combination with other antibiotics did not lead to adverse effects necessitating discontinuation. HDD should be considered in this selected patient population, particularly when high MIC organisms are identified.

Clinical Isolates of Pseudomonas aeruginosa from Chronically Infected Cystic Fibrosis Patients Fail To Activate the Inflammasome during Both Stable Infection and Pulmonary Exacerbation

Immune recognition of pathogen-associated ligands leads to assembly and activation of inflammasomes, resulting in the secretion of inflammatory cytokines IL-1β and IL-18 and an inflammatory cell death called pyroptosis. Inflammasomes are important for protection against many pathogens, but their role during chronic infectious disease is poorly understood. Pseudomonas aeruginosa is an opportunistic pathogen that persists in the lungs of cystic fibrosis (CF) patients and may be responsible for the repeated episodes of pulmonary exacerbation characteristic of CF. P. aeruginosa is capable of inducing potent inflammasome activation during acute infection. We hypothesized that to persist within the host during chronic infection, P. aeruginosa must evade inflammasome activation, and pulmonary exacerbations may be the result of restoration of inflammasome activation. We therefore isolated P. aeruginosa from chronically infected CF patients during stable infection and exacerbation and evaluated the impact of these isolates on inflammasome activation in macrophages and neutrophils. P. aeruginosa isolates from CF patients failed to induce inflammasome activation, as measured by the secretion of IL-1β and IL-18 and by pyroptotic cell death, during both stable infection and exacerbation. Inflammasome evasion likely was due to reduced expression of inflammasome ligands and reduced motility and was not observed in environmental isolates or isolates from acute, non-CF infection. These results reveal a novel mechanism of pathogen adaptation by P. aeruginosa to avoid detection by inflammasomes in CF patients and indicate that P. aeruginosa-activated inflammasomes are not involved in CF pulmonary exacerbations.

Host response to Staphylococcus aureus cytotoxins in children with cystic fibrosis

BACKGROUND

Staphylococcus aureus is one of the earliest bacterial pathogens to colonize the lungs of children with cystic fibrosis and is an important contributor to pulmonary exacerbations. The adaptive host response to S. aureus in cystic fibrosis remains inadequately defined and has important implications for pathogenesis and potential interventions. The objectives of this study were to determine the functional antibody response to select staphylococcal exotoxins (LukAB, alpha-hemolysin, and PVL) in children with cystic fibrosis and to evaluate the relationship of this response with pulmonary exacerbations.

METHODS

Fifty children with cystic fibrosis were enrolled and followed prospectively for 12months. Clinical characteristics and serologic profiles were assessed at routine visits and during pulmonary exacerbations, and functional antibody assessments were performed to measure neutralization of LukAB-mediated cytotoxicity.

RESULTS

For each antigen, geometric mean titers were significantly higher if S. aureus was detected at the time of exacerbation. For LukAB, geometric mean titers were significantly higher at exacerbation follow-up compared to titers during the exacerbation, consistent with expression during human disease, and the humoral response capably neutralized LukAB-mediated cytotoxicity. Moreover, the presence of a positive S. aureus culture during a pulmonary exacerbation was associated with 31-fold higher odds of having a LukA titer ≥1:160, suggesting potential diagnostic capability of this assay.

CONCLUSIONS

The leukotoxin LukAB is expressed by S. aureus and recognized by the human adaptive immune response in the setting of pulmonary infection in cystic fibrosis. Anti-LukAB antibodies were not only predictive of positive staphylococcal culture during exacerbation, but also functional in the neutralization of this toxin.

The Effect of Structural Violence on Patients with Sickle Cell Disease

Sickle Cell Disease (SCD) is a burdensome and prevalent condition predominantly seen in populations of African heritage. Treatments for SCD, particularly those related to pain crisis, are largely insufficient. We argue that it is through structural violence-a systemic series of policies, institutions, and practices-that individuals who live with SCD suffer from health disparities. Similarly, we argue against other suggested mechanisms and causes, such as purely economic factors or low public interest and knowledge. We shall do this in part by comparing the systemic response to SCD to that of Cystic Fibrosis (CF), another genetic based illness with similar prevalence. Notably, CF that affects a very different target population, and has very different research, funding, and treatment trajectories. Underlying these arguments is the hypothesis that structural violence can harm a population in a developed nation just as it can in a developing one.

Utilization of antibiotics for methicillin-resistant Staphylococcus aureus infection in cystic fibrosis

OBJECTIVES

The purpose of this study was to characterize the utilization of antibiotics for chronic methicillin-resistant Staphylococcus aureus (MRSA) infection in cystic fibrosis (CF) patients with acute pulmonary exacerbations (PEx).

METHODS

An anonymous national cross-sectional survey of CF Foundation accredited care programs was performed using an electronic survey tool.

RESULTS

Fifty-eight percent (152/261) CF Foundation accredited programs completed the survey. Ninety-eight percent (149/152) of respondents reported using antibiotics (oral or intravenous) against MRSA. Variability exists in the use of antibiotics amongst the programs and in the dosages utilized. For oral outpatient treatment, sulfamethoxazole/trimethoprim was the most commonly utilized antibiotic by both pediatric (109/287, 38%) and adult (99/295, 34%) respondents, of which, ten percent of reported to use it in combination with rifampin. For inpatient treatment, linezolid (both intravenous (IV) and oral) was most commonly utilized in both pediatric (IV 35/224, 16%; oral 41/224, 18%), and adult (IV 44/235, 19%; oral 38/235, 16%) respondents for inpatient treatment. IV vancomycin was the second most commonly utilized antibiotic by pediatric (70/224, 31%) and adult (71/235, 30%) respondents. Most respondents reported dose titration to achieve a vancomycin trough level of 15-20 mg/L (150/179, 84%). Topical or inhaled antibiotic utilization was reported to be an uncommon practice with approximately 70% of pediatric and adult respondents reporting to use them either rarely or never. The concomitant use of anti-MRSA and anti-pseudomonal antibiotics was common with 96% of pediatric and 99% of adult respondents answering in the affirmative.

CONCLUSION

We conclude that anti-MRSA antibiotics are utilized via various dosage regimens by a majority of CF Foundation accredited care programs for the treatment of chronic MRSA in PEx, and there is no consensus on the best treatment approach.

Emerging bacterial pathogens and changing concepts of bacterial pathogenesis in cystic fibrosis

Chronic suppurative lower airway infection is a hallmark feature of cystic fibrosis (CF). Decades of experience in clinical microbiology have enabled the development of improved technologies and approaches for the cultivation and identification of microorganisms from sputum. It is increasingly apparent that the microbial constituents of the lower airways in CF exist in a dynamic state. Indeed, while changes in prevalence of various pathogens occur through ageing, differences exist in successive cohorts of patients and between clinics, regions and countries. Classical pathogens such as Pseudomonas aeruginosa, Burkholderia cepacia complex and Staphylococcus aureus are increasingly being supplemented with new and emerging organisms rarely observed in other areas of medicine. Moreover, it is now recognized that common oropharyngeal organisms, previously presumed to be benign colonizers may contribute to disease progression. As infection remains the leading cause of morbidity and mortality in CF, an understanding of the epidemiology, risk factors for acquisition and natural history of infection including interactions between colonizing bacteria is required. Unified approaches to the study and determination of pathogen status are similarly needed. Furthermore, experienced and evidence-based treatment data is necessary to optimize outcomes for individuals with CF.

Successful treatment of multiresistant Achromobacter xylosoxidans bacteremia in a child with acute myeloid leukemia

Achromobacter xylosoxidans is an aerobic gram-negative bacillus and important cause of bacteremia in immunocompromised patients. We describe a leukemia pediatric patient with severe neutropenia who developed bacteremia with A xylosoxidans resistant to multiple antibiotics, and treated the patient with tigecycline and piperacillin-tazobactam in addition to supportive medications.

Tobramycin inhalation powder: an efficient and efficacious therapy for the treatment of Pseudomonas aeruginosa infection in cystic fibrosis

Inhaled antipseudomonal therapies are critical components in the management of cystic fibrosis (CF) and have significantly contributed to improved patient outcomes. Dry powder inhaler technologies represent a significant advance in drug delivery, alleviating treatment burden and potentially improving adherence associated with traditional CF nebulized therapies. Tobramycin inhalation powder (TIP) uses PulmoSphere® technology for very efficient drug delivery into the lower airways. In placebo-controlled and comparative studies with traditional tobramycin formulations, TIP is equally efficacious and is associated with increased patient convenience and satisfaction. TIP has been recommended in the 2013 CF Foundation and the 2014 European guidelines as a therapy in CF for the maintenance of lung health. Going forward, TIP may offer a therapeutic advantage over traditional formulations of tobramycin as recent prospective ‘real world’ studies of TIP have demonstrated high patient tolerance and improved adherence compared with traditional formulations.

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.

Intravenous and Inhaled Antimicrobials at Home in Cystic Fibrosis Patients

The primary clinical characteristics of cystic fibrosis (CF) are malnutrition caused by malabsorption secondary to pancreatic insufficiency, chronic pulmonary infections, and male infertility. The major cause of morbidity and mortality are bronchiectasis and obstructive pulmonary disease. Lung disease in CF is manifested by this chronic lung disease progression, with intermittent episodes of acute worsening of symptoms called pulmonary exacerbations. Once the patient has stabilized, and if suitable care can be arranged, these interventions are often transitioned to the home. This review summarizes important points pertinent to the use of intravenous and inhaled antimicrobials that may be encountered by prescribers, nurses, technicians, and case managers in the home health setting. Appropriate dosing, indications, adverse drug reactions, monitoring parameters, and practicality of both intravenous and inhaled antimicrobials are discussed.

New strategies against Stenotrophomonas maltophilia: a serious worldwide intrinsically drug-resistant opportunistic pathogen

Stenotrophomonas maltophilia is a worldwide human opportunistic pathogen associated with serious infections in humans, and is most often recovered from respiratory tract infections. In addition to its intrinsic drug resistance, this organism may acquire resistance via multiple molecular mechanisms. New antimicrobial strategies are needed to combat S. maltophilia infections, particularly in immunocompromised patients, cystic fibrosis patients with polymicrobial infections of the lung, and in patients with chronic infections. This editorial reports on newer drugs and antimicrobial strategies and their potential for use in treatment of S. maltophilia infections, the development of new technologies to detect this organism, and identifies strategies currently in use to reduce transmission of this pathogen.

Tobramycin Inhalation Powder (TIP): An Efficient Treatment Strategy for the Management of Chronic Pseudomonas Aeruginosa Infection in Cystic Fibrosis

Repeated bouts of acute and chronic lung infections are responsible for progressive pulmonary function decline in individuals with cystic fibrosis (CF), ultimately leading to respiratory failure and death. Pseudomonas aeruginosa is the archetypical CF pathogen, causes chronic infection in 70% of individuals, and is associated with an accelerated clinical decline. The management of P. aeruginosa in CF has been revolutionized with the development and widespread use of inhaled antibiotics. Aerosol delivery of antimicrobial compounds in CF enables extremely high concentrations of antibiotics to be reached directly at the site of infection potentially overcoming adaptive resistance and avoiding the potential for cumulative systemic toxicities. Tobramycin inhalation powder (TIP) represents the first dry powder inhaled (DPI) antibiotic available for use in CF. DPIs are notable for a markedly reduced time for administration, ease of portability, and increased compliance. TIP has been developed as a therapeutic alternative to tobramycin inhalation solution (TIS), the standard of care for the past 20 years within CF. Relative to TIS 300 mg nebulized twice daily in on-and-off cycles of 28 days duration, TIP 112 mg twice daily via the T-326 inhaler administered on the same schedule is associated with marked time savings, increased patient satisfaction, and comparable clinical end points. TIP represents an innovative treatment strategy for those individuals with CF and holds the promise of increased patient compliance and thus the potential for improved clinical outcomes.

Comparison of in Vitro Activity of Doripenem versus Old Carbapenems against Pseudomonas Aeruginosa Clinical Isolates from both CF and Burn Patients

PURPOSE

The antimicrobial activity of doripenem in comparison of imipenem, meropenem and ertapenem among Pseudomonas aeruginosa isolated from burn and Cystic Fibrosis (CF) patients were determined.

METHODS

Metallo-β-lactamase (MBL) genes in imipenem non susceptible P. aeruginosa isolates were detected using PCR method. The in vitro susceptibilities of doripenem, imipenem, meropenem and ertapenem were determined by Etests. MIC50 and MIC90 for corresponding antibiotics were determined individually in burn and CF isolates.

RESULTS

Among isolates which were resistant to imipenem, 16 isolates were positive for the bla IMP gene. All isolates had no bla VIM gene. All MBL producing isolates were excluded. MIC50/MIC90 of doripenem in CF and burn isolates were 0.75/>32 and >32/>32 mg/L respectively. The corresponding values for imipenem in CF and burn isolates were 2/>32 and >32/>32 mg/L, respectively.

CONCLUSION

The susceptibility rate of doripenem is higher than that of imipenem and meropenem among P.aeruginosa isolated from CF patients, whereas, there is no difference between the efficiency of doripenem and old carbapenems in non MBL producing P.aeruginosa isolates in burn patients.

Comprehensive allergy work-up is mandatory in cystic fibrosis patients who report a history suggestive of drug allergy to beta-lactam antibiotics

BACKGROUND

In the general population, reports on suspected ß-lactam hypersensitivity are common. After a drug allergy work-up at best 20% of the selected patients are positive. However, these considerations have not been explored in cystic fibrosis patients for whom antibiotics are even more crucial.

METHODS

The study, part of the Drug Allergy and Hypersensitivity (DAHD) cohort, was performed in the regional cystic fibrosis center of Montpellier, France. After identifying patients with a clinical history suggestive of drug allergy to ß-lactams, a complete drug allergy work-up, was carried out according to the EAACI recommendations.

RESULTS

Among the 171 patients involved, 23 reported clinical manifestations potentially compatible with a drug allergy to ß-lactams. After performing the complete drug-allergy work-up, 7 were considered as drug hypersensitive (3 had positive skin tests, 1 a positive provocation test, 3 declined the tests). Excluding the latter 3 patients with incomplete drug allergy work-up, the rate of proven drug allergy was 2.3%.

CONCLUSIONS

Drug allergy to ß-lactams in cystic fibrosis patients is of importance. A full drug allergy work-up is mandatory in case of suspicion, because ß-lactam responsibility is often ruled out.

Update on methicillin-resistant Staphylococcus aureus in cystic fibrosis

PURPOSE OF REVIEW

Respiratory infection is a major contributor to morbidity and mortality in cystic fibrosis (CF). One infection the CF community is particularly concerned about is methicillin-resistant Staphylococcus aureus (MRSA). Worldwide, the prevalence of MRSA has been rising and the impact on clinical outcomes and optimal prevention and treatment strategies are unclear.

RECENT FINDINGS

Studies have demonstrated MRSA is independently associated with poor clinical outcomes, even after taking into account severity of illness. Additionally, characteristics of MRSA strains, such as small colony variants and borderline oxacillin-resistant S. aureus, may be important in predicting the subsequent clinical course. The treatment of MRSA has had variable results and emergence of resistance to commonly prescribed antibiotics is a concern.

SUMMARY

The evidence to date supports MRSA infection is independently associated with worse outcomes. The next step is to build upon the current research to expand the knowledge about the impact different strains of MRSA have on infection control strategies and MRSA treatment protocols. Interventions should balance patient safety, efficacy, and treatment burden to improve the quality and length of life in patients with CF.

Characterization of BmKbpp, a multifunctional peptide from the Chinese scorpion Mesobuthus martensii Karsch: gaining insight into a new mechanism for the functional diversification of scorpion venom peptides

BmKbpp is a novel cationic and α-helical peptide from the Chinese scorpion Mesobuthus martensii Karsch, of which function or biological activity has not been characterized so far. Here we showed that BmKbpp possesses strong antimicrobial activity against both Gram-positive and Gram-negative bacteria with a MIC range from 2.3 μM to 68.2 μM for the majority of tested bacteria. BmKbpp also inhibits the growth of tested fungi with an IC50 range from 0.2 μM to 3.1 μM. Because BmKbpp potently inhibits the growth of some antibiotics-resistant pathogens, and shows very weak hemolytic activity, it has considerable potentials for therapeutic applications. Moreover, we found that BmKbpp markedly inhibits the superoxide production in granulocytes or HL-60 cells at the concentrations of submicromolar level; this suggests that BmKbpp can act as a signaling molecule involving innate immune regulation at low concentrations. The C-terminal region of BmKbpp (BmKbpp-C) shows 72% similarity to the peptide K-12, a bradykinin-potentiating peptide. We found that both BmKbpp and BmKbpp-C possess bradykinin-potentiating activity, and the activity of BmKbpp-C is stronger than that of BmKbpp. PCR amplification for the genomic gene of BmBpp showed that it is not a continuous sequence in the genome; it suggests that BmKbpp could come from a recombination event in transcript level. Taken together, our data suggest that multi-functionalization of a single peptide, which is probably mediated by trans-splicing, could be a new mechanism for the functional diversification of scorpion venom peptides.

Tomatidine acts in synergy with aminoglycoside antibiotics against multiresistant Staphylococcus aureus and prevents virulence gene expression

OBJECTIVES

This study characterized the multiple biological activities of the natural compound tomatidine against Staphylococcus aureus. Notably, this work examined the antibacterial activity of tomatidine in combination with other antibiotics and the influence of this compound on the expression of virulence factors in S. aureus.

METHODS

The effect of tomatidine on the susceptibility of S. aureus to several antibiotic classes was determined by a broth microdilution procedure and a chequerboard protocol to measure fractional inhibitory concentration indices and to reveal drug interactions. Time-kill experiments for aminoglycoside/tomatidine combinations were also performed. The haemolytic ability of several strains in the presence of tomatidine was measured on blood agar plates and the expression of virulence-associated genes in strain ATCC 29213 treated with tomatidine was monitored by quantitative PCR.

RESULTS

Tomatidine specifically potentiated the inhibitory effect of aminoglycosides but not of other classes of drugs. This potentiating effect was observed against strains of different clinical origins (human blood, cystic fibrosis airways, osteomyelitis, skin tissues and bovine mastitis), including aminoglycoside-resistant bacteria possessing the aac(6')-aph(2″), ant(4')-Ia and aph(3')-IIIa genes. The killing kinetics for the combination of aminoglycosides with tomatidine revealed strong bactericidal activity. Although tomatidine did not possess growth-inhibitory activity of its own against prototypical S. aureus, it inhibited the haemolytic activity of several strains and, more specifically, blocked the expression of several genes normally influenced by the agr system.

CONCLUSIONS

These results show that tomatidine is an aminoglycoside potentiator that also acts as an anti-virulence agent targeting both antibiotic-susceptible and antibiotic-resistant S. aureus.

Review: Staphylococcus aureus and MRSA in cystic fibrosis

BACKGROUND

Staphylococcus aureus (S. aureus) is one of the earliest bacteria detected in infants and children with cystic fibrosis (CF). The rise of methicillin resistant S. aureus (MRSA) in the last 10 years has caused a lot of attention to this organism.

RESULTS

The aim of this review is to provide a general overview of methicillin sensitive S. aureus (MSSA) and MRSA, discuss special aspects of S. aureus in cystic fibrosis, and to review treatment concepts. Microbiology of the organism will be reviewed along with data regarding the epidemiology of both MSSA and MRSA. Antibiotic treatments both in regards to acute management and eradication of MSSA and MRSA will be reviewed. Prophylaxis of MSSA in CF remains controversial. Treatment with anti-staphylococcal agents reduces the infection rate with MSSA but may lead to a higher rate of infection with P. aeruginosa. In regards to MRSA, there is a paucity of clinical data regarding approaches to eradication.

CONCLUSIONS

To advance the care of CF patients, controlled clinical trials are urgently needed to find the optimal approach to treating CF patients who are infected with either MSSA or MRSA.

Management of refractory Pseudomonas aeruginosa infection in cystic fibrosis

Cystic fibrosis (CF) is the most common life-limiting inherited disease in Caucasian populations. The main cause of death in CF patients is respiratory failure resulting from chronic pulmonary infection. Pseudomonas aeruginosa is the most prevalent organism in the airway colonization of CF patients, and its persistence in the airways has been related to greater morbidity with a more rapid deterioration in lung function. P. aeruginosa has enormous genetic and metabolic flexibility that allows it to adapt and persist within the airways of CF patients, and it has the ability to easily acquire antimicrobial resistance. For these reasons, the management of infections and chronic colonization by P. aeruginosa remains a challenge for physicians. This article reviews the current and future antibacterial chemotherapy options for respiratory pseudomonal infection in CF patients.