Ototoxicity
James R. Tysome, Rahul G. Kanegaonkar in Hearing, 2015
The drugs most commonly attributed to causing ototoxicity include aminoglycosides, platinum-based chemotherapeutic agents, salicylates, loop diuretics and quinines. Ototoxicity typically results in high frequency sensorineural hearing loss, tinnitus and, if the vestibular system is also affected, imbalance. Aminoglycosides are the most common class of drugs causing ototoxicity. Patients who have undergone systemic therapy with aminoglycosides should be monitored for ototoxicity for up to 6 months after treatment. It is important to take a family history of ototoxicity in patients where aminoglycoside treatment is planned. Many topical antibiotic drops used commonly in the ear contain aminoglycosides, as they are effective against common ear pathogens such as Pseudomonas aeruginosa. They can be safely used in the ear with an intact tympanic membrane without any risk of ototoxicity. The incidence of ototoxicity in patients taking loop diuretics is 6–7%, with tinnitus and disequilibrium being the main symptoms experienced.
Extracellular Degradative Enzymes
Michael F. Cole in Unifying Microbial Mechanisms, 2019
This chapter examines degradative enzymes as classes, specifically proteases, glycosidases and phospholipases. It focuses on pathogen proteases that degrade host proteins, proteases produced by pathogens are involved in degrading pathogen surface proteins once they have performed their function(s). Many extracellular proteases are secreted in an inactive form termed a zymogen. Proteases may have a narrow or broad range of specificity. Microbial proteases inactivate plasma serine protease inhibitors. Two saprophytic bacteria, Clostridium perfringens and Pseudomonas aeruginosa, whose natural habitat is soil and water but are also opportunistic bacterial human pathogens, produce a plethora of degradative enzymes. In addition to secreted degradative enzymes that degrade host molecules, both pathogenic prokaryotes and eukaryotes possess cytoplasmic and membrane proteases that play important roles in controlling expression and solubility of determinants of pathogenesis. The role(s) of degradative enzymes in pathogenesis depend on the environments in which the bacteria that produce them operate.
Some Bacterial and Synthetic Polysaccharides
Stephen E. Harding, Michael P. Tombs, Gary G. Adams, Berit Smestad Paulsen, Kari Tvete Inngjerdingen, Hilde Barsett in An Introduction to Polysaccharide Biotechnology, 2017
Pseudomonas aeruginosa, commonly found in respiratory tract infections, produces alginate which contributes to blockage in the respiratory tract, which leads to further infection, while similar blockage of phloem in plants has been described. Bacterial products are very important in most aspects of polysaccharide biotechnology. Xanthan has been food grade approved by the US Food and Drug Administration. This makes it not only attractive as a food product but also for use in packaging material in contact with food and in pharmaceutical and biomedical applications that involve ingestion. The high suspension stability is made use of in pharmaceutical cream formulations and in barium sulphate preparations. Gellan is obtained from cultures of Pseudomonas elodea found on elodea plant. It is isolated by ethanol precipitation from the culture medium and may be partially deacetylated by alkali treatment. The ability of cyclodextrins to enclose smaller molecules and effectively to sequester them from solution has led to a number of applications.
Orbital ecthyma gangrenosum in multiple myeloma
Published in Baylor University Medical Center Proceedings, 2019
Ecthyma gangrenosum is a rare and highly lethal cutaneous infection classically associated with Pseudomonas aeruginosa bacteremia. We report a 58-year-old man with multiple myeloma receiving chemotherapy who presented with 2 days of painless left periorbital swelling that rapidly progressed to a blackish eschar. His absolute neutrophil count was 0.10/mm3; platelet count, 14,000/mm3; and hemoglobin, 6 g/dL. Computed tomography showed diffuse left periorbital cellulitis. Blood cultures grew pan-sensitive Pseudomonas aeruginosa, and the patient died from sepsis and multiorgan failure.
Epidemiology of cystic fibrosis respiratory pathogens isolated at a South African Hospital, 2006–2010
Published in Southern African Journal of Infectious Diseases, 2016
Vindana Chibabhai, Warren Lowman
Background: The epidemiology of cystic fibrosis (CF) associated pathogens other than Pseudomonas aeruginosa in the South African cystic fibrosis population has not been previously described. Methods: A retrospective review of respiratory cultures taken from cystic fibrosis clinic patients at the Charlotte Maxeke Johannesburg Academic Hospital from 2006 to 2010 was performed. Results: During the study period, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cepacia complex and Candida albicans prevalence remained stable, Aspergillus fumigatus increased from 8% to 20% (p = 0.0132); Staphylococcus aureus decreased from 66% to 50% (p = 0.0243) and Haemophilus influenzae decreased from 13% to 3% (p = 0.0136). There were significant antimicrobial susceptibility changes to meropenem (p
Comparative efficacies of contact lens disinfecting solutions against Pseudomonas aeruginosa
Published in Clinical and Experimental Optometry, 2011
Mohammad Aghazadeh Amiri, Mohadeseh Mohammadinia, Mehdi Tabatabaee, Farshad Askarizadeh, Abbas Behgozin
Purpose: The aim of the present study was to evaluate the disinfection properties of multipurpose contact lens disinfection solutions, based on the International Organization for Standardization (ISO) 14729 guidelines. Methods: Three lots of each of six multi‐purpose solutions were tested as follows: Renu MultiPlus, Solo Care Aqua, All‐Clean Soft, Contact All‐in one Advanced, Hippia, Ginza multi‐purpose solution and 0.9% normal saline solution were inoculated with the standard strain of Pseudomonas aeruginosa (ATCC 9027). The surviving bacteria were quantified at specified times. An average logarithm reduction in bacterial numbers at the manufacturer's minimum recommended disinfection time was determined and compared with the criteria for stand‐alone disinfection products for each multi‐purpose disinfection solution against each bacterial strain. Results: Renu MultiPlus, Solo Care, All‐Clean Soft and Contact All‐in one Advanced were effective in achieving a four logarithmic units reduction in the bacterial count; however, Renu MultiPlus and Solo Care Aqua resulted in the greatest reduction in bacterial numbers. The other solutions were not effective against Pseudomonas aeruginosa after specified times. Conclusions: Generally, Renu MultiPlus, Solo Care Aqua, All‐Clean Soft and Contact All‐in one Advanced meet the ISO 14729 guidelines for stand‐alone contact lens solutions.