Prevalence of bacteria identified in respiratory secretions from patients with CF , by age cohort Consequences of  Chronic infection with P. Aeruginosa and MRSA   PERIODIC SURVEILLANCE CULTURES Antibiotics for Treatment of acute pulmonary exacerbations Early eradication of MRSA Prevention of acquisition of chronic airways infection

1. Antibiotic therapy for
pulmonaryinfection in
Cystic fibrosis
Dr Ola Alkhars
General Pediatric Consultant
27/10/2022

2. Objectives:
Introduction
Prevalence
Case scenarios
Clinical Use of sputum culture results
Antibiotics for Treatment of acute pulmonary exacerbations
Antibiotics for persistent respiratory colonization
Prevention of acquisition of chronic airways infection

3. Cystic fibrosis (CF)
• Is a multisystem disorder caused by
pathogenic variants in the CFTR gene ,
located on chromosome 7
• Pulmonary disease remains the leading
cause of morbidity and mortality in patients
with CF
• (CF) lung disease is characterized by
persistent bacterial infection.

5. Prevalenceof bacteriaidentified in respiratorysecretionsfrom
patientswithCF , by age cohort

6. Pseudomonas
aeruginosa
• The CF airway is particularly susceptible
to P. aeruginosa, with infection occurring as
early as the first year of life.
• The prevalence of P. aeruginosa increases
with age

7. Methicillin-resistant
Staphylococcus
aureus
➢the pathogen is difficult to eradicate
once the infection is established.

8. Consequencesof ChronicinfectionwithP. Aeruginosaand
MRSA
• Accelerated loss of pulmonary function
• Worsens prognosis
• Decreased survival

9. PERIODICSURVEILLANCECULTURES
• Cultures of expectorated sputum or throat swabs should be performed at
least every three months during routine clinic visits.

10. Use the sputumculture results
●To guide selection of antibiotics in the event of
an acute exacerbation
●To monitor for the acquisition of P. aeruginosa,
and initiate chronic treatment with inhaled
antibiotics for chronically infected patients

11. Antibioticsfor Treatmentof acute pulmonary
exacerbations
• Virtuallyall guidelines for treatment of pulmonary exacerbationsrecommend selecting antibiotics
based on the bacteria identifiedby culture of respiratorysecretions
• Since CF patientsoften carry the same bacteria for long periods of time, these cultures are relatively
predictive of what will be found in specimens obtainedat the start of a pulmonary exacerbation.

12. Antibiotics for treating exacerbations of CF
lung disease

13. Antibiotics for treating exacerbations of CF
lung disease

14. Antibiotics for treating exacerbations of CF
lung disease

15. Antibiotics for treating exacerbations of CF
lung disease

17. • The traditional practice of using susceptibility test results to guide
selection is being questioned and actively reexamined
• Adviced to prescribe the same antibiotic regimen that
was previously successful, unless the bacteria identified
in respiratory secretions have changed since the last episode.

18. Earlyeradication of
P. aeruginosa
• Using a protocol to detect and
treat P. aeruginosa when it is first acquired,
regardless of age or whether there are
associated clinical signs or symptoms
• The therapy is repeated only if surveillance
cultures show recurrence of P. aeruginosa

19. PersistentP. aeruginosa infection
• chronic treatment with inhaled tobramycin is recommended
• Inhaled aztreonam lysine is a reasonable alternative, as is
inhaled colistin
• The inhaled antibiotic is typically cycled between 28 days on and 28
days off treatment.
• For patients with deteriorating pulmonary status and/or recurrent
pulmonary exacerbations despite cyclic treatment with a single
inhaled antibiotic, it is becoming common practice to administer
inhaled antibiotics continuously, by alternating 28 days of one
antibiotic with 28 days of another.

20. • Prescribing chronic or intermittentoral antibiotic therapy other
than oral azithromycinis not recommended

21. Early eradication of MRSA
Randomized study that showed successful eradication , which consisted
of
• oral rifampin
• oral trimethoprim-sulfamethoxazole
• or minocycline
• nasal mupirocin
• chlorhexidine oral rinses and body wipes
• Environmental decontamination

22. Eradication of chronic MRSAinfection
• Combined oral, inhaled, and topical antibiotics have been tested for
their ability to eradicate chronic MRSA infection from patients with CF.
• In a randomized study, subjects with chronic MRSA infection received
either inhaled vancomycin or placebo for 28 days . Both groups received
oral and topical anti-MRSA antibiotics and undertook environmental
cleaning to limit MRSA re-exposure. The rate of MRSA eradication one
month after treatment, was 20 percent in both groups.

23. Preventionof acquisitionof chronic airways infection
• A randomized trial evaluatedthe effects of treating childrenwithout P. aeruginosa infection with
cycles of oral ciprofloxacin andinhaled colistin. Three-week courses of these medicationswere
administeredevery three months for three years. At the end of the three-year trial, there was no
difference between rates of initialor chronic P. aeruginosa infection among childrenwho had
received this interventionas compared with controls.
Prophylactic use of antibiotics targeting P. aeruginosa or S. aureus is not recommended

24. • Chronicpulmonaryinfection in CFpatient is an independent riskfactor for:
• Accelerated loss of pulmonaryfunction
• Worsens prognosis.
• PERIODIC SURVEILLANCE CULTURES should be performed at least every
three months duringroutine clinicvisits.
• Advised to prescribe the same antibioticregimen that was previously
successful, unless the bacteria identified in respiratory secretionshave
changed since the last episode.
• Prophylacticuse of antibiotics targeting P. aeruginosa or S. aureus is not
recommended

25. References
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• Shteinberg M, Haq IJ, PolineniD, Davies JC. Cystic fibrosis. Lancet 2021; 397:2195.
• Cystic Fibrosis Foundation. 2019 PatientRegistry: AnnualData Report. 2020.
Available at: https://www.cff.org/Research/Researcher-Resources/Patient-
Registry/2019-Patient-Registry-Annual-Data-Report.pdf (Accessed on July 26, 2021).
• Gibson RL, Burns JL, Ramsey BW. Pathophysiology and managementof pulmonary
infections in cystic fibrosis. AmJ Respir Crit Care Med 2003; 168:918.
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