Topics in Clinical Microbiology: Pseudomonas cepacia

Microbiology and management of respiratory infections in children with tracheostomy

Tracheostomy-related respiratory infections are common, though the diagnosis and management can be challenging in children. The goal of this review article was to provide an overview of the current knowledge known about recognizing and treating respiratory infections in this population and to emphasize future areas for further research. While several small and retrospective papers attempt to provide information, there remain more questions than answers. We have reviewed ten published articles to understand this topic, bringing to light significant variation in clinical practices across institutions. While identifying the microbiology is important, it is also crucial to recognize when to treat. Differentiating acute infection, chronic infection, and colonization are important features that influence the treatment of lower respiratory tract infection in children with a tracheostomy.

Consequences of Viral Infection and Cytokine Production During Pregnancy on Brain Development in Offspring

Infections during pregnancy can seriously damage fetal neurodevelopment by aberrantly activating the maternal immune system, directly impacting fetal neural cells. Increasing evidence suggests that these adverse impacts involve alterations in neural stem cell biology with long-term consequences for offspring, including neurodevelopmental disorders such as autism spectrum disorder, schizophrenia, and cognitive impairment. Here we review how maternal infection with viruses such as Influenza A, Cytomegalovirus, and Zika during pregnancy can affect the brain development of offspring by promoting the release of maternal pro-inflammatory cytokines, triggering neuroinflammation of the fetal brain, and/or directly infecting fetal neural cells. In addition, we review insights into how these infections impact human brain development from studies with animal models and brain organoids. Finally, we discuss how maternal infection with SARS-CoV-2 may have consequences for neurodevelopment of the offspring.

Fatal pneumonia caused by Burkholderia cepacia 9 months after resection of aspergilloma

A 69-year-old man developed an episode of severe community-acquired pneumonia 9 months after resection of aspergilloma. Although Aspergillus fumigatus was also isolated in the pleural cavity, it did not invade the remaining lung parenchyma. The patient developed progressive bilateral pneumonia leading to death from respiratory failure. Burkholderia cepacia was considered as prime pathogen, as it was repeatedly cultured from sputum and tracheal secretions, as well as the autopsy lung. B. cepacia is resistant to most antibiotics, and seldom causes pneumonia in patients without cystic fibrosis or chronic granulomatous disease. The precise reason that this apparently immunocompetent patient developed B. cepacia pneumonia remains unknown.

Recovery of Burkholderia pseudomallei and B. cepacia from drinking water

Samples of drinking water were examined in order to evaluate the occurrence of two gram-negative bacteria: Burkholderia pseudomallei and B. cepacia. A total of 85 samples were collected from public and private buildings in the province of Bologna (Italy). Other bacteriological indicators (heterotrophic plate count at 22 and 36 degrees C) were also examined, together with physical and chemical parameters (temperature, pH, residual chlorine, total hardness and chemical oxygen demand (COD)). High levels of B. pseudomallei were recovered (mean value = 578 cfu/100 ml) in about 7% of samples, while B. cepacia was recovered in 3.5% (mean value = < 1) of the samples. The two microorganisms were found to correlate positively with heterotrophic plate counts at 22 and 36 degrees C, but not with the physical and chemical parameters taken into consideration.

Endemic burkholderia cepacia bacteraemia: clinical features and antimicrobial susceptibilities of isolates

Burkholderia cepacia has emerged as a nosocomial pathogen, causing numerous outbreaks, particularly among cystic fibrosis (CF) patients. Reports of clinical features of endemic B. cepacia bacteraemia in non-CF patients are rare. Twenty-five patients with B. cepacia bacteraemia were matched with 25 controls with nosocomial Escherichia coli bacteraemia at China Medical College Hospital, Taichung, Taiwan, over a period of 3 y. Case-patients included 16 men and 9 women, from 13 to 75 y. All had severe underlying diseases, most commonly malignancy (44%). Twenty-four patients (96%) had nosocomial infections. Five patients (20%) had polymicrobial bacteraemia. Our controls included 11 men and 14 women, age range 18-80 y. The most common underlying disease was malignancy (44%). Multivariate analysis revealed that indwelling central venous catheter was the significant risk factor predisposing to B. cepacia bacteraemia (p= 0.025). Eleven case-patients met the definition of catheter-related bloodstream infection. Fifteen patients (60%) received appropriate antimicrobial therapy after notification of positive blood cultures and susceptibility patterns. The overall case-fatality rate was 12% (3/25), only 1 of whom died of B. cepacia bacteraemia. There was no statistically significant difference in overall mortality rate between case-patients and controls. All isolates were susceptible to ceftazidime, piperacillin and minocycline and 84% of the isolates were susceptible to imipenem. B. cepacia should be considered a potential pathogen in hospitalized patients with severe underlying diseases, particularly those with indwelling central venous catheters.

Antimicrobial therapy against Staphylococcus aureus, Pseudomonas aeruginosa, and Pseudomonas cepacia

The aims of antimicrobial therapy extend beyond short-term bacterial killing to long-term maintenance of weight and lung function. A review of antimicrobial drug trials shows that empiricism is still ahead of science and more studies are needed both to justify current practice and to make future changes logical.

Indolent epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia in an intensive care unit traced to a contaminated blood gas analyzer

An epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia occurred in the medical intensive care unit at the Clinical Center of the National Institutes of Health. Sixteen patients in the intensive care unit became colonized or infected with this organism in a 21-month period; whereas P. cepacia had been isolated only 16 times in the preceding 90 months from the entire hospital. Further analysis demonstrated a significant association of the epidemic cases with bloodstream isolation of the organism (p less than 0.001, Fisher's exact test). Mortality associated with bacteremia caused by P. cepacia was 38 percent. Intensive investigation of the intensive care unit and its surrounding environment eventually demonstrated that a blood gas analyzer in a satellite laboratory adjacent to the intensive care unit was the reservoir for the outbreak. Replacement of the machine resulted in termination of the outbreak, P. cepacia continues to represent an environmental threat to hospitalized patients.