Challenges and mitigation strategies associated with Burkholderia cepacia complex contamination in pharmaceutical manufacturing.

Burkholderia cepacia complex (BCC) is a Gram-negative, non-spore-forming bacterium with more than 20 opportunistic pathogenic species, most commonly found in soil and water. Due to their rapid mutation rates, these organisms are adaptable and possess high genomic plasticity. BCC can cause life-threatening infections in immunocompromised individuals, such as those with cystic fibrosis, chronic granulomatous disease, and neonates. BCC contamination is a significant concern in pharmaceutical manufacturing, frequently causing non-sterile product recalls. BCC has been found in purified water, cosmetics, household items, and even ultrasound gel used in veterinary practices. Pharmaceuticals, personal care products, and cleaning solutions have been implicated in numerous outbreaks worldwide, highlighting the risks associated with intrinsic manufacturing site contamination. Regulatory compliance, product safety, and human health protection depend on testing for BCC in pharmaceutical manufacturing. Identification challenges exist, with BCC often misidentified as other bacteria like non-lactose fermenting Escherichia coli or Pseudomonas spp., particularly in developing countries where reporting BCC in pharmaceuticals remains limited. This review comprehensively aims to address the organisms causing BCC contamination, genetic diversity, identification challenges, regulatory requirements, and mitigation strategies. Recommendations are proposed to aid pharmaceutical chemists in managing BCC-associated risks and implementing prevention strategies within manufacturing processes.

Identification of two distinct phylogenomic lineages and model strains for the understudied cystic fibrosis lung pathogen Burkholderia multivorans.

Burkholderia multivorans is the dominant Burkholderia pathogen recovered from lung infection in people with cystic fibrosis. However, as an understudied pathogen there are knowledge gaps in relation to its population biology, phenotypic traits and useful model strains. A phylogenomic study of B. multivorans was undertaken using a total of 283 genomes, of which 73 were sequenced and 49 phenotypically characterized as part of this study. Average nucleotide identity analysis (ANI) and phylogenetic alignment of core genes demonstrated that the B. multivorans population separated into two distinct evolutionary clades, defined as lineage 1 (n=58 genomes) and lineage 2 (n=221 genomes). To examine the population biology of B. multivorans, a representative subgroup of 77 B. multivorans genomes (28 from the reference databases and the 49 novel short-read genome sequences) were selected based on multilocus sequence typing (MLST), isolation source and phylogenetic placement criteria. Comparative genomics was used to identify B. multivorans lineage-specific genes - ghrB_1 in lineage 1 and glnM_2 in lineage 2 - and diagnostic PCRs targeting them were successfully developed. Phenotypic analysis of 49 representative B. multivorans strains showed considerable inter-strain variance, but the majority of the isolates tested were motile and capable of biofilm formation. A striking absence of B. multivorans protease activity in vitro was observed, but no lineage-specific phenotypic differences were demonstrated. Using phylogenomic and phenotypic criteria, three model B. multivorans CF strains were identified, BCC0084 (lineage 1), BCC1272 (lineage 2a) and BCC0033 lineage 2b, and their complete genome sequences determined. B. multivorans CF strains BCC0033 and BCC0084, and the environmental reference strain, ATCC 17616, were all capable of short-term survival within a murine lung infection model. By mapping the population biology, identifying lineage-specific PCRs and model strains, we provide much needed baseline resources for future studies of B. multivorans.

Clinical characteristics, drug resistance and death risk factors of Burkholderia cepacia infection in hematopoietic stem cell transplant patients.

BACKGROUND: Burkholderia cepacia (BC) has been detected more and more in infected patients in recent years. However, as a high-risk population, the clinical characteristics and prognosis of BC infection in hematopoietic stem cell transplantation (HSCT) patients have not been reported. The purpose of this study is to obtain data that will help fill in the gaps in this field, provide evidence for reducing the mortality rate of BC infection in HSCT patients, and guide the use of antibiotics in the future. METHODS: Electronic medical records of patients with BC infection who underwent HSCT in Xiangya Hospital of Central South University from September 1, 2015 to August 31, 2021 were collected. At the same time, 1:1 case-control matching was conducted according to gender, age and disease type. Comparisons between patients with/without BC infection and respiratory failure were made respectively, and the sensitivity of BC to five clinically commonly used antibiotics was also evaluated. Univariate and multivariate analyses were performed to identify independent risk factors for death. RESULTS: The most common site of BC infection in HSCT patients was the lung (75%). Although BC infection rate (3.74%) and antibiotic resistance were not significant, it was closely associated with a higher risk of death (P = 0.022), which even further increased to 90.9% when combined with respiratory failure (P = 0.008). Procalcitonin > 10 µg/L (HR = 40.88, 95% CI 6.51-256.63, P = 0.000) and septic shock (HR = 4.08, 95% CI 1.02-16.33, P = 0.047) were two independent risk factors for death. CONCLUSION: HSCT patients with BC infection are in critical condition, and the management of respiratory infection should be especially strengthened to improve the prognosis of these patients.

Activity of Aerosolized Levofloxacin against Burkholderia cepacia in a Mouse Model of Chronic Lung Infection.

Burkholderia cepacia complex is an opportunistic pathogen capable of causing chronic pulmonary infections. These studies were conducted to demonstrate the activity of aerosolized levofloxacin in a chronic mouse lung infection model caused by B. cepacia isolates from patients with cystic fibrosis. Treatment with aerosolized levofloxacin for 4 days produced at least 1 log CFU of bacterial killing against all strains tested, suggesting possible utility in the treatment of lung infections caused by B. cepacia isolates.

Phenotypic diversity and genotypic flexibility of Burkholderia cenocepacia during long-term chronic infection of cystic fibrosis lungs.

Chronic bacterial infections of the lung are the leading cause of morbidity and mortality in cystic fibrosis patients. Tracking bacterial evolution during chronic infections can provide insights into how host selection pressures-including immune responses and therapeutic interventions-shape bacterial genomes. We carried out genomic and phenotypic analyses of 215 serially collected Burkholderia cenocepacia isolates from 16 cystic fibrosis patients, spanning a period of 2-20 yr and a broad range of epidemic lineages. Systematic phenotypic tests identified longitudinal bacterial series that manifested progressive changes in liquid media growth, motility, biofilm formation, and acute insect virulence, but not in mucoidy. The results suggest that distinct lineages follow distinct evolutionary trajectories during lung infection. Pan-genome analysis identified 10,110 homologous gene clusters present only in a subset of strains, including genes restricted to different molecular types. Our phylogenetic analysis based on 2148 orthologous gene clusters from all isolates is consistent with patient-specific clades. This suggests that initial colonization of patients was likely by individual strains, followed by subsequent diversification. Evidence of clonal lineages shared by some patients was observed, suggesting inter-patient transmission. We observed recurrent gene losses in multiple independent longitudinal series, including complete loss of Chromosome III and deletions on other chromosomes. Recurrently observed loss-of-function mutations were associated with decreases in motility and biofilm formation. Together, our study provides the first comprehensive genome-phenome analyses of B. cenocepacia infection in cystic fibrosis lungs and serves as a valuable resource for understanding the genomic and phenotypic underpinnings of bacterial evolution.

Of onions and men: Report of cavitary community acquired pneumonia due to Burkholderia cepacia complex in an immunocompetent patient and review of the literature.

Burkholderia cepacia complex consists of highly antibiotic resistant gram negative bacilli that are plant symbionts and also potential agents of human infection.  This bacterial family's claim to fame in clinical medicine is as the scourge of cystic fibrosis patients, in whom it is a notorious respiratory pathogen.  Outside of cystic fibrosis, it rarely comes to mind as an etiology of community acquired pneumonia with or without lung cavitation in immunocompetent hosts.  We describe a case of an otherwise healthy, community-dwelling man who presented with subacute cavitary lung disease, the causative organism of which turned out to be Burkholderia cepacia complex.  Our report is accompanied by a review of the literature, which identified an additional eleven cases in the same category.  We analyze all of the available cases for the emergence of any identifiable patterns or peculiarities.

Burkholderia multivorans septicemia in a pediatric liver transplant patient.

"Cepacia syndrome", caused by Burkholderia cepacia complex and often associated with cystic fibrosis, carries a high mortality rate. It is rare for Burkholderia multivorans, a species within the B. cepacia complex, to cause cepacia syndrome even among patients with cystic fibrosis. This is the first reported fatal case of cepacia syndrome caused by B. multivorans occurring in a pediatric liver transplant recipient who does not have cystic fibrosis. We describe the unique characteristics of this pathogen among the non-cystic fibrosis population and the importance of early recognition and treatment.

An Oxygen-Sensing Two-Component System in the Burkholderia cepacia Complex Regulates Biofilm, Intracellular Invasion, and Pathogenicity.

Burkholderia dolosa is a member of the Burkholderia cepacia complex (BCC), which is a group of bacteria that cause chronic lung infection in patients with cystic fibrosis (CF) and can be associated with outbreaks carrying high morbidity and mortality. While investigating the genomic diversity of B. dolosa strains collected from an outbreak among CF patients, we previously identified fixL as a gene showing signs of strong positive selection. This gene has homology to fixL of the rhizobial FixL/FixJ two-component system. The goals of this study were to determine the functions of FixLJ and their role in virulence in B. dolosa. We generated a fixLJ deletion mutant and complemented controls in B. dolosa strain AU0158. Using a fixK-lacZ reporter we found that FixLJ was activated in low oxygen in multiple BCC species. In a murine pneumonia model, the B. dolosa fixLJ deletion mutant was cleared faster from the lungs and spleen than wild-type B. dolosa strain AU0158 at 7 days post infection. Interestingly, the fixLJ deletion mutant made more biofilm, albeit with altered structure, but was less motile than strain AU0158. Using RNA-seq with in vitro grown bacteria, we found ~11% of the genome was differentially expressed in the fixLJ deletion mutant relative to strain AU0158. Multiple flagella-associated genes were down-regulated in the fixLJ deletion mutant, so we also evaluated virulence of a fliC deletion mutant, which lacks a flagellum. We saw no difference in the ability of the fliC deletion mutant to persist in the murine model relative to strain AU0158, suggesting factors other than flagella caused the phenotype of decreased persistence. We found the fixLJ deletion mutant to be less invasive in human lung epithelial and macrophage-like cells. In conclusion, B. dolosa fixLJ is a global regulator that controls biofilm formation, motility, intracellular invasion/persistence, and virulence.

Impact of clonally-related Burkholderia contaminans strains in two patients attending an Italian cystic fibrosis centre: a case report.

BACKGROUND: Burkholderia contaminans is one of the 20 closely related bacterial of the Burkholderia cepacia complex, a group of bacteria that are ubiquitous in the environment and capable of infecting people with cystic fibrosis (CF). This species is an emerging pathogen and it has been widely isolated from CF patients in Argentina, Spain, Portugal, Australia, Canada, USA with a low prevalence in Ireland, France, Russia, Switzerland, Czech Republic, and Italy. This is the first report of B. contaminans affecting two Italian CF patients attending the same CF Centre. We correlate B. contaminans colonisation with lung function decline and co-infection with other clinically relevant CF pathogens. CASE PRESENTATION: B. contaminans was identified by Multi Locus Sequence Typing in routine sputum analysis of two Caucasian CF women homozygous for Phe508del CFTR mutation. Sequence Type 102 was detected in both strains. It is known that B. contaminans ST102 was isolated both from CF and non-CF patients, with an intercontinental spread across the world. Random Amplified Polymorphic DNA analysis revealed the genetic relatedness between the two strains. We examined their susceptibility to antimicrobial agents, comparing the latter with that recorded for other B. contaminans isolated from different countries. We also described key virulence factors possibly linked with a clinical outcome. Specifically, we attempted to correlate colonization with the incidence of acute exacerbation of symptoms and lung function decline. CONCLUSIONS: This case presentation suggests that acquisition of B. contaminans ST102 is not directly associated with a lung function decline. We retain that the presence of other CF pathogens (i.e. MRSA and Trichosporon) along with B. contaminans ST102 might have contributed to the worsening of clinical conditions in our CF patients. The circumstances leading to the establishment of B. contaminans ST102 infections are still unknown. We highlight the importance to proper detect and typing bacteria implicated in CF infection by using molecular techniques.

[Development and evaluation of an in-house database for quick identification of Burkholderia contaminans by MALDI-TOF MS]. / Desarrollo y evaluación de una base de datos in house para la identificación rápida de Burkholderia contaminans por EM MALDI-TOF.

MALDI-TOF (matrix assisted laser desorption ionization-time of flight) mass spectrometry (MS) proved to be a robust tool for the identification of numerous taxonomic groups. However, it has limitations. A key advantage of this technique is the flexibility for the incorporation of protein profiles of microorganisms not included in the commercial database. Due to the prevalence of Burkholderia contaminans in fibrocystic patients in Argentina and the fact that rapid and reliable microbiological diagnosis is crucial in them, MALDI-TOF MS emerges as a strategic tool. The aim of this work was to develop an additional database with peptide spectra of reference isolates of B. contaminans. This database demonstrated to be successful for the identification of 97% of the isolates analyzed. Therefore, MALDI-TOF MS with the extended database was a useful tool for the identification and differentiation of other related species to B. contaminans.

Clinical characteristics of cystic fibrosis patients prior to lung transplantation: An international comparison between Canada and the United States.

BACKGROUND: Cystic fibrosis (CF) patients from Canada have better-reported post-lung transplant survival compared to patients from the United States. We hypothesized the clinical characteristics of CF patients prior to lung transplant differ between the two countries. METHODS: Population-based cohort study utilizing combined Canadian CF Registry and US CF Foundation Patient Registry data from 1986 to 2013. Demographic and clinical variables were analyzed prior to lung transplant. RESULTS: Between 1986 and 2013, 607 (10.2%) CF patients underwent lung transplantation in Canada and 3428 (7.5%) in the United States. A lower proportion of recipients had growth of B. cepacia complex prior to transplant in the United States compared to Canada (0.8% vs 4.3%). Lung function was similar between recipients from the two countries. The proportion of patients classified as underweight was significantly higher in the United States compared to Canada (39.8% vs 28.0%; SD 26.1) despite higher rates of feeding tube use (42.5% vs 28.6%; SD 29.0). CONCLUSIONS: CF lung transplant recipients from the United States have similar lung function, lower rates of B. cepacia complex, and worse nutritional parameters prior to transplant compared to counterparts in Canada. Future studies are necessary to evaluate the impact of these differences on post-transplant survival.

Implementation of a successful eradication protocol for Burkholderia Cepacia complex in cystic fibrosis patients.

BACKGROUND: Infection with Burkholderia cepacia complex (Bcc) results in a heterogeneous clinical course ranging from asymptomatic colonization of the airways to fulminant respiratory failure in patients with cystic fibrosis (CF). Early eradication of Pseudomonas aeruginosa improves clinical outcomes. The efficacy and clinical outcomes following implementation of an eradication protocol for Bcc are less well understood. METHODS: We developed and implemented a single center Bcc eradication protocol that included an intensive combination of intravenous, inhaled, and oral antibiotic therapies based on in vitro sensitivities. We conducted a retrospective cohort analysis of clinical outcomes compared to patients with chronic Bcc infection. RESULTS: Six patients were identified as having a newly acquired Bcc colonization and were placed on the eradication protocol. Sequential sputum samples after completion of the protocol demonstrated sustained clearance of Bcc in all patients. Lung function and nutritional status remained stable in the year following eradication. CONCLUSION: Clearance of Bcc from sputum cultures using a standardized protocol was successful at one year and was associated with clinical stability.

[Burkholderia cepacia infection in children: a clinical analysis of 16 cases].

OBJECTIVE: To investigate the distribution characteristics and clinical features of Burkholderia cepacia infection in children. METHODS: A retrospective analysis was performed for the clinical data of 16 children with Burkholderia cepacia infection who were hospitalized between June 2012 and September 2017. RESULTS: All 16 children with Burkholderia cepacia infection were sporadic cases. A total of 16 strains of Burkholderia cepacia were isolated, among which 8 were detected by sputum culture, 5 were detected by blood culture, 2 were detected by tracheal intubation tip culture, and 1 was detected by lung biopsy culture. Of the 16 children, there were 11 boys and 5 girls, with an age of 5 days to 6 years, and the children aged <1 year accounted for 69%. As for department distribution, 10 children were in the PICU/NICU and 6 were in the general wards. As for clinical manifestations, one child had disseminated intravascular coagulation, and the other 15 children had pulmonary infection, among who 11 had severe pneumonia (8 of them underwent mechanical ventilation during treatment). As for underlying diseases, 2 had severe congenital heart disease, 4 had primary immunodeficiency, 3 were highly suspected of immunodeficiency or inherited metabolic diseases, 1 had tracheal stenosis, 1 had Kawasaki disease, 1 was a preterm infant with bronchopulmonary dysplasia, 1 had severe cleft lip and palate, and 3 had no definite underlying diseases. Of all the children, 7 also had infections with adenovirus and Mycoplasma. The average length of hospital stay was 20.3 days for all children, and 12 were improved and 4 died after treatment. All 16 strains of Burkholderia cepacia had a drug resistance rate of 100% to amikacin and gentamicin and ≥80% to ampicillin/sulbactam and ticarcillin/clavulanic acid, as well as the lowest drug resistance rate to levofloxacin. CONCLUSIONS: Burkholderia cepacia is an opportunistic pathogen often found in immunocompromised children and can produce drug resistance. The presence or absence of underlying diseases should be considered during anti-infective therapy. The children with Burkholderia cepacia infection often have a poor prognosis, and an understanding of the disease spectrum of Burkholderia cepacia infection helps with clinical diagnosis and treatment.

Clinical and microbiological profile of chronic Burkholderia cepacia complex infections in a cystic fibrosis reference hospital in Brazil.

Burkholderia sp. infections are extremely complex in cystic fibrosis (CF) patients, especially considering the lack of knowledge regarding its behavior, its relationship with prognosis, as well as its transmissibility and multidrug resistance features. This study evaluated the frequency of chronic infection by Burkholderia, using microbiological and clinical data. Ninety-eight patients with CF attended from July 2011 to April 2014 in a Brazilian reference hospital were included. Antimicrobial activity, molecular epidemiology, Shwachman score, body mass index, exacerbations, and lung function were analyzed. Nine patients had chronic colonization, and all of them showed preserved pulmonary function levels, body mass index, and Shwachman score. Meropenem was the most effective antibiotic; however, divergent results were shown by other studies. Cross-contamination may have occurred in only two unrelated patients of different ages, who were colonized by B. vietnamiensis, which does not occur frequently. Twelve new sequence types (STs) were identified and three STs have presented intercontinental distribution. None of the patients presented known epidemic strains. In conclusion, a relatively low number of patients with chronic colonization and suspected cross-infection were identified. Different from other studies that have found CF patients chronically colonized with Burkholderia sp. having a greater deterioration of lung function, more frequent antibiotic therapy, and increased mortality, in the current study, the patients showed good clinical outcomes and favorable options for antibiotics therapy. This study also updated the epidemiological database, which facilitates the multicentric collaborative analysis and assists in the control of global infection by these pathogens.

Clinafloxacin for Treatment of Burkholderia cenocepacia Infection in a Cystic Fibrosis Patient.

Respiratory infection with Burkholderia cenocepacia is associated with accelerated decline in lung function and increased mortality in cystic fibrosis (CF) patients (A. M. Jones, M. E. Dodd, J. R. W. Govan, V. Barcus, C. J. Doherty, J. Morris, and A. K. Webb, Thorax 59:948-951, 2004, http://dx.doi.org/10.1136/thx.2003.017210). B. cenocepacia often possesses innate resistance to multiple antimicrobial classes, making eradication uncommon in established infection (P. B. Davis, Am J Respir Crit Care Med 173:475-482, 2006, http://dx.doi.org/10.1164/rccm.200505-840OE). We report the use of clinafloxacin in a CF patient with advanced B. cenocepacia infection, present pharmacokinetic (PK) data, and discuss the potential therapeutic role of clinafloxacin in patients with this condition.

Burkholderia cepacia complex in Serbian patients with cystic fibrosis: prevalence and molecular epidemiology.

The Burkholderia cepacia complex (Bcc) organisms remain significant pathogens in patients with cystic fibrosis (CF). This study was performed to evaluate the prevalence, epidemiological characteristics, and presence of molecular markers associated with virulence and transmissibility of the Bcc strains in the National CF Centre in Belgrade, Serbia. The Bcc isolates collected during the four-year study period (2010-2013) were further examined by 16 s rRNA gene, pulsed-field gel electrophoresis of genomic DNA, multilocus sequence typing analysis, and phylogenetic analysis based on concatenated sequence of seven alleles. Fifty out of 184 patients (27.2 %) were colonized with two Bcc species, B. cenocepacia (n = 49) and B. stabilis (n = 1). Thirty-four patients (18.5 %) had chronic colonization. Typing methods revealed a high level of similarity among Bcc isolates, indicating a person-to-person transmission or acquisition from a common source. New sequence types (STs) were identified, and none of the STs with an international distribution were found. One centre-specific ST, B. cenocepacia ST856, was highly dominant and shared by 48/50 (96 %) patients colonized by Bcc. This clone was characterized by PCR positivity for both the B. cepacia epidemic strain marker and cable pilin, and showed close genetic relatedness to the epidemic strain CZ1 (ST32). These results indicate that the impact of Bcc on airway colonization in the Serbian CF population is high and virtually exclusively limited to a single clone of B. cenocepacia. The presence of a highly transmissible clone and probable patient-to-patient spread was observed.

The first reported case of Burkholderia contaminans in patients with cystic fibrosis in Ireland: from the Sargasso Sea to Irish Children.

BACKGROUND: Burkholderia contaminans is an emerging pathogen in the cystic fibrosis (CF) setting. Included in the Burkholderia cepacia complex (Bcc), B. contaminans is a Gram negative, motile, obligate aerobe previously classified as a pseudomonad. Previous reports have described B. contaminans isolation from patients in Portugal, Switzerland, Spain, Argentina and the USA. This, however, is the first report relating to B. contaminans affecting Irish patients with CF, initially detected in a paediatric setting. CASE PRESENTATION: Burkholderia contaminans was identified in the routine analysis of sputum from a fourteen year old boy, at his annual review and subsequently from the sputum from his 19 year old brother. RecA gene sequencing and pulsed field gel electrophoresis (PFGE) were unable to distinguish between the isolates, which demonstrated with susceptibility to ciprofloxacin, cotrimoxazole, meropenem, pipercillin/tazobactam and ceftazidime. Both isolates were resistant to aztreonam, with reduced susceptibility to tobramycin. Following treatment with intravenous meropenem and ceftazidime, oral ciprofloxacin and nebulised tobramycin for 6 weeks, sputum specimens from both patients were negative for B. contaminans. No other member of the local CF cohort proved positive. CONCLUSIONS: Bcc bacteria are associated with poor prognosis in CF and decreased life expectancy, specifically leading to a more rapid decline in lung function and, in some cases, to a fatal necrotizing pneumonia known as the "cepacia syndrome". Some species exhibit innate resistance to multiple antimicrobial agents and their transmission rate can be high in susceptible patients. In that context, we describe the first incidence of CF-related B. contaminans in Ireland and its successful eradication from two patients, one paediatric, using an aggressive antimicrobial regimen.

Forced oscillations and respiratory system modeling in adults with cystic fibrosis.

BACKGROUND: The Forced Oscillation Technique (FOT) has the potential to increase our knowledge about the biomechanical changes that occur in Cystic Fibrosis (CF). Thus, the aims of this study were to investigate changes in the resistive and reactive properties of the respiratory systems of adults with CF. METHODS: The study was conducted in a group of 27 adults with CF over 18 years old and a control group of 23 healthy individuals, both of which were assessed by the FOT, plethysmography and spirometry. An equivalent electrical circuit model was also used to quantify biomechanical changes and to gain physiological insight. RESULTS AND DISCUSSION: The CF adults presented an increased total respiratory resistance (p < 0.0001), increased resistance curve slope (p<0.0006) and reduced dynamic compliance (p<0.0001). In close agreement with the physiology of CF, the model analysis showed increased peripheral resistance (p<0.0005) and reduced compliance (p < 0.0004) and inertance (p<0.005). Significant reasonable to good correlations were observed between the resistive parameters and spirometric and plethysmographic indexes. Similar associations were observed for the reactive parameters. Peripheral resistance, obtained by the model analysis, presented reasonable (R=0.35) to good (R=0.64) relationships with plethysmographic parameters. CONCLUSIONS: The FOT adequately assessed the biomechanical changes associated with CF. The model used provides sensitive indicators of lung function and has the capacity to differentiate between obstructed and non-obstructed airway conditions. The FOT shows great potential for the clinical assessment of respiratory mechanics in adults with CF.

Deep pyoderma caused by Burkholderia cepacia complex associated with ciclosporin administration in dogs: a case series.

BACKGROUND: Bacteria of the Burkholderia cepacia complex (Bcc) are ubiquitous Gram-negative bacilli associated with fatal nosocomial infections in humans; multi-antibiotic resistance makes this organism a serious threat in hospital settings. OBJECTIVE: To describe the historical, clinicopathological and treatment characteristics of Bcc-associated deep skin infections in dogs. ANIMALS: Six dogs with skin infections in which skin bacterial cultures resulted in pure growth of Bcc. METHODS: Retrospective study with review of medical records and skin biopsies. RESULTS: All dogs were receiving oral ciclosporin at the time of skin infection development. All dogs were castrated males and four of six were West Highland white terriers. Cutaneous lesions consistent with deep pyoderma were confined mainly to the trunk. In all dogs skin cytology revealed a strong inflammatory response, with moderate to abundant numbers of intracellular (neutrophils and macrophages) and extracellular bacilli. In three dogs histopathology showed a multifocal, nodular to coalescing pyogranulomatous dermatitis associated with multifocal folliculitis and furunculosis. Tissue Giemsa and Gram stains identified numerous Gram-negative rods within macrophages. Antimicrobial susceptibility testing revealed multidrug-resistant Bcc strains with sensitivity to trimethoprim/sulfonamides in all dogs and to marbofloxacin, piperacillin and ceftazidime in three dogs. Successful treatment was achieved in all dogs using trimethoprim/sulfonamides or quinolones (marbofloxacin, ciprofloxacin) or doxycycline in conjunction with ciclosporin withdrawal. CONCLUSIONS AND CLINICAL IMPORTANCE: Clinicians should be aware of the rare potential for Bcc-associated deep skin infections in dogs receiving oral ciclosporin. Owners should be made conscious of the potential transmission risk to humans or other animals.

Depletion of the ubiquitin-binding adaptor molecule SQSTM1/p62 from macrophages harboring cftr ΔF508 mutation improves the delivery of Burkholderia cenocepacia to the autophagic machinery.

Cystic fibrosis is the most common inherited lethal disease in Caucasians. It is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), of which the cftr ΔF508 mutation is the most common. ΔF508 macrophages are intrinsically defective in autophagy because of the sequestration of essential autophagy molecules within unprocessed CFTR aggregates. Defective autophagy allows Burkholderia cenocepacia (B. cepacia) to survive and replicate in ΔF508 macrophages. Infection by B. cepacia poses a great risk to cystic fibrosis patients because it causes accelerated lung inflammation and, in some cases, a lethal necrotizing pneumonia. Autophagy is a cell survival mechanism whereby an autophagosome engulfs non-functional organelles and delivers them to the lysosome for degradation. The ubiquitin binding adaptor protein SQSTM1/p62 is required for the delivery of several ubiquitinated cargos to the autophagosome. In WT macrophages, p62 depletion and overexpression lead to increased and decreased bacterial intracellular survival, respectively. In contrast, depletion of p62 in ΔF508 macrophages results in decreased bacterial survival, whereas overexpression of p62 leads to increased B. cepacia intracellular growth. Interestingly, the depletion of p62 from ΔF508 macrophages results in the release of the autophagy molecule beclin1 (BECN1) from the mutant CFTR aggregates and allows its redistribution and recruitment to the B. cepacia vacuole, mediating the acquisition of the autophagy marker LC3 and bacterial clearance via autophagy. These data demonstrate that p62 differentially dictates the fate of B. cepacia infection in WT and ΔF508 macrophages.