Burkholderia Cepacia Research Articles

Burkholderia cepacia immobilized onto rGO as a biomaterial for the removal of naphthalene from wastewater

As one of the polycyclic aromatic hydrocarbons (PAHs), naphthalene is of serious environmental concern due to its carcinogenicity, persistence and refractory degradation. In this study, a new functional biomaterial based on Burkholderia cepacia (BK) immobilized on reduced graphene oxide (rGO) was prepared, resulting in the removal of 99.0% naphthalene within 48 h. This was better than the 67.3% for free BK and 55.6% for rGO alone. Various characterizations indicated that reduced graphene oxide-Burkholderia cepacia (rGO-BK) was successfully synthesized and secreted non-toxic and degradable surfactants which participated in the degradation of naphthalene. The adsorption kinetics and degradation kinetics conformed best to non-linear pseudo-second-order and pseudo-first-order kinetic models, respectively. Demonstrated in this work is that removing naphthalene by rGO-BK involved both chemically dominated adsorption and biodegradation. As well, GC-MS analysis revealed two things: firstly, that the degraded products of naphthalene were dibutyl phthalate, diethyl phthalate, phthalic acid, and benzoic acid; and secondly, two potentially viable biodegradation pathways of naphthalene by rGO-BK could be proposed. Finally, for practical application experiment, the rGO-BK was exposed to river water samples and generated 99% removal efficiency of naphthalene, so this study offers new insights into biomaterials that can remove naphthalene.

Exploring the views of infection consultants in England on a novel delinked funding model for antimicrobials: the SMASH study.

A novel 'subscription-type' funding model was launched in England in July 2022 for ceftazidime/avibactam and cefiderocol. We explored the views of infection consultants on important aspects of the delinked antimicrobial funding model. An online survey was sent to all infection consultants in NHS acute hospitals in England. The response rate was 31.2% (235/753). Most consultants agreed the model is a welcome development (69.8%, 164/235), will improve treatment of drug-resistant infections (68.5%, 161/235) and will stimulate research and development of new antimicrobials (57.9%, 136/235). Consultants disagreed that the model would lead to reduced carbapenem use and reported increased use of cefiderocol post-implementation. The presence of an antimicrobial pharmacy team, requirement for preauthorization by infection specialists, antimicrobial stewardship ward rounds and education of infection specialists were considered the most effective antimicrobial stewardship interventions. Under the new model, 42.1% (99/235) of consultants would use these antimicrobials empirically, if risk factors for antimicrobial resistance were present (previous infection, colonization, treatment failure with carbapenems, ward outbreak, recent admission to a high-prevalence setting).Significantly higher insurance and diversity values were given to model antimicrobials compared with established treatments for carbapenem-resistant infections, while meropenem recorded the highest enablement value. Use of both 'subscription-type' model drugs for a wide range of infection sites was reported. Respondents prioritized ceftazidime/avibactam for infections by bacteria producing OXA-48 and KPC and cefiderocol for those producing MBLs and infections with Stenotrophomonas maltophilia, Acinetobacter spp. and Burkholderia cepacia. The 'subscription-type' model was viewed favourably by infection consultants in England.

Systemic Burkholderia cepacia complex in a patient with ACLF associated to extreme polarization of the intestinal microbiota toward the phylum Proteobacteria

Burkholderia cepacia (Bcc) bloodstream infection, without bacterial peritonitis, has not been reported in cirrhosis. We report the case of a 51-year-old male inpatient with alcohol-associated cirrhosis complicated on admission, who was unresponsive to treatment and died 48 hours later. Thirty minutes before the patient’s death, stool and blood samples were taken. Albeit cultures were negative, Sanger and metagenomic sequencing of 16S-rRNA and ITS2 genes from samples revealed systemic infection dominated by Bcc, however other Proteobacteria were also identified. Interestingly, we observed that gut microbiota polarized toward Proteobacteria/Gammaproteobacteria/Enterobacteriaceae/Escherichia/Shigella, which suggests bacterial translocation as a source of systemic infection. Regarding Bcc, it is resistant to several antibiotics, hence timely and accurate molecular tests might help to improve clinical outcomes.

Improving Protection to Prevent Bacterial Infections: Preliminary Applications of Reverse Vaccinology against the Main Cystic Fibrosis Pathogens.

Reverse vaccinology is a powerful tool that was recently used to develop vaccines starting from a pathogen genome. Some bacterial infections have the necessity to be prevented then treated. For example, individuals with chronic pulmonary diseases, such as Cystic Fibrosis, are prone to develop infections and biofilms in the thick mucus that covers their lungs, mainly caused by Burkholderia cepacia complex, Haemophilus influenzae, Mycobacterium abscessus complex, Pseudomonas aeruginosa and Staphylococcus aureus. These infections are complicated to treat and prevention remains the best strategy. Despite the availability of vaccines against some strains of those pathogens, it is necessary to improve the immunization of people with Cystic Fibrosis against all of them. An effective approach is to develop a broad-spectrum vaccine to utilize proteins that are well conserved across different species. In this context, reverse vaccinology, a method based on computational analysis of the genome of various microorganisms, appears as one of the most promising tools for the identification of putative targets for broad-spectrum vaccine development. This review provides an overview of the vaccines that are under development by reverse vaccinology against the aforementioned pathogens, as well as the progress made so far.

Development of a qPCR detection approach for pathogenic Burkholderia cenocepacia associated with fresh vegetables

Natural environment serves as a reservoir for Burkholderia cepacia complex organisms, including the highly transmissible opportunistic human pathogen B. cenocepacia. Currently, there is a lack of an effective and quantitative method for B. cenocepacia detection in fresh food and other environmental niches. A quantitative real-time PCR (qPCR) detection method for B. cenocepacia bacteria was established in this study and validated using artificially inoculated fresh vegetable samples. Genome-wide comparative methods were applied to identify target regions for the design of species-specific primers. Assay specificity was measured with 12 strains of closely related Burkholderia bacteria and demonstrated the primer pair BCF6/R6 were 100% specific for detection of B. cenocepacia. The described qPCR assay evaluated B. cenocepacia with a 2 pg μl−1 limit of detection and appropriate linearity (R2 = 0.999). In 50 samples of experimentally infected produce (lettuce, onion, and celery), the assay could detect B. cenocepacia as low as 2.6 × 102 cells in each sample equal to 1 g. The established qPCR method quantitatively detects B. cenocepacia with high sensitivity and specificity, making it a promising technique for B. cenocepacia detection and epidemiological research on B. cepacia complex organisms from fresh vegetables.

Isolation and Identification of Bacteria from Soil Contaminated With Textile Dye And Tannery Effluents In Sokoto Metropolis

Soil contamination by textile and tannery effluents is a great concern to the environment, Complex effluents having a number of dyes accumulate in the soil there by polluting the environments and loss of microbial species in the soil. Samples were collected and the physicochemical analyses was determined. The pH was basic with 8.0 and 10.1 from tannery and dyeing site respectively. The organic carbon was very low with 0.76% and 0.06%, Nitrogen (0.067% and 0,095%), phosphorus 0.8mg/kg, and 1.62mg/kg), calcium (1.35mol/kg in both the two samples. Magnesium recorded 0.30mol/kg and 1.65mol/kg, potassium 0.85 mol/kg1.65mol/kg , Sodium 3.13mol/kg and 30.0 mol/kg in tannery and dyeing site respectively. The sand, silt and clay recorded (78.8% and 90.6%)(7.3% and 5.3%), (13.9% and 4.1%). The heavy metal content of the soil sample were determined the concentration of chromium was 0.0258 and 0.0043 from tannery and dyeing site respectively, while Nickel was almost unavailable in the site with -1.0700 and -1.0756. Lead recorded a very low concentration with -0.9164 and -7803. Thirteen bacterial species were isolated and identified based on morphology and biochemical charachteristics from the samples, tannery soil with frequency occurrences of 23.07% for Bacillus laterosporus, 15.38% for Bacillus subtilis and Bacillus megaterium while Bacillus firmus, Bacillus cereus, proteus vulgaris, proteus mirabilis and clostridium had 7.69% each. Fifteen species were isolated from the dyeing soil sample with Bacillus subtilis, Bacillus megaterium, and Pseudomonas aeruginosa with the highest frequency of occurrences with13.33% each. Burkholderia cepacia, P. florescense, Bacillus laterosporus,Bacillus amyloliquifeciens, Bacillus brevis and Proteus vulgaris had 6.66% each, all these were determine with the use of Microgen identification kit, molecular analysis was done on two bacterial isolates and were confirmed to be Alishwanella solinqauinati and Bacillus subtilis. These indicate that the species isolated can resist high amount of toxic chemicals and can withstand any harsh environment and hence their ability to serve as a potential biosorbents for bioremediation of the affected environments at a cheap cost.

Copper Phthalocyanine Improving Nonaqueous Catalysis of Pseudomonas cepacia Lipase for Ester Synthesis.

The nonaqueous catalysis of lipases is significant for synthesis of high pure esters, but they usually behave low catalytic activity due to denaturation and aggregation of enzyme protein in organic phases. To improve the nonaqueous catalysis, the inexpensive copper phthalocyanine was taken as a new carrier on which Pseudomonas cepacia lipase was immobilized by physical absorption, and used for synthesis of hexyl acetate, an important flavor, via transesterification of hexanol and vinyl acetate. Results showed that the desired loading was 10-mg lipase immobilized on 10-mg copper phthalocyanine powder. When the immobilized lipase was employed in the reaction system consisted of 1.5-mL hexanol and 1.5-mL vinyl acetate at 37°C and 160 rpm, the conversion was fivefolds of that catalyzed by native lipase after 1 h, and reached 99.0% after 8 h. In six times of 8-h reuses, the immobilized lipase behaved an activity attenuation rate 1.22% h-1, lower than 1.77% h-1 of native lipase, which meant that the immobilized lipase was more stable. Even at the room temperature and the static state without shaking or stirring, the immobilized lipase still brought conversion 42.8% after 10 h and the native lipase gave 20.1%. Obviously, the immobilized lipase is an available biocatalyst in organic phase and has great potential in food industry.

DJ STENT COLONIZATION PATTERNS: EXPLORING MICROBIAL PROFILES AND CLINICAL RELEVANCE

With the advancement of endourology, a great variety of biomaterial devices have been developed. Several studies have reported that the formation of biofilm and device infection are commonly observed manifestations that lead to urinary tract infections. An indwelling double J ureteral stent carries a significant risk; a negative urine culture does not rule out a colonized stent. Hence, assessing the extent of stent colonization without positive voided urine culture is crucial. This cross-sectional study involved 44 patients, aged between 14 to 88 years, coming to the Department of Urology at Indus Hospital Karachi to remove DJ stents from April 2019 to October 2019. The samples were collected through a non-probability consecutive technique. Urine samples, before removal of the stent along with distal portions of the DJ stent, were sent for cultural analysis to study bacteriuria and stent colonization. The whole data was analyzed on SPSS version 22.0. The study found that five patients (11.4%) had colonization of the distal end of the DJ stent, and Burkholderia cepacia was the most common microorganism. However, n=31; 70.4% of patients had colonization in post-DJ stent urine, and Pseudomonas was the most common microorganism (n=14; 45.2%). Stent colonization had no significant association with age, gender, and positive urine culture. Most colonized stents were asymptomatic. Despite these observations, it is critical to emphasize that using DJ stents is still a generally recognized and safe treatment. Future studies should look at other aspects that colonization patterns may impact in improving the safety and management of DJ stent use.

Burkholderia cepacia Vertebral Osteomyelitis Following Cesarean Section: Case Report and Review of the Literature

The Burkholderia cepacia complex (Bcc) initially emerged as an important opportunistic pathogen in patients with predisposing lung disease. Bcc infections outside the respiratory tract are less common, although their incidence has been increasing particularly in immunocompromised patients. We herein describe the case of a healthy young woman who started experiencing low back pain 2 weeks after an uncomplicated cesarean section. She was found to have vertebral osteomyelitis at T12-L1. CT guided biopsy was performed, and cultures grew Bcc. She was treated with 3 weeks of meropenem and 5 weeks of oral trimethoprim-sulfamethoxazole with good response. No surgical intervention was warranted. We also performed a review of the literature on other existing reports. To the best of our knowledge, this is the first case of Bcc vertebral osteomyelitis in an immunocompetent patient following an obstetric procedure.

Phenotypic detection of multi-drug resistant MBL-producing Gram-negative bacteria isolated from clinical samples of patients in hospitals in Akwa Ibom State, Nigeria

Metallo-beta-lactamase (MBL)-producing Gram-negative bacteria (GNB) continue to be a bane in the treatment of clinical infections in both community and hospital settings. Prompt detection of multidrug resistant (MDR) strains using antimicrobial susceptibility testing (AST) and MBL detection are vital for therapeutic options. The aim of this study was to determine the prevalence, distribution and antibiotic susceptibility of MDR and MBL-producing GNB from clinical samples in health facilities in Akwa Ibom State. A total of 480 samples comprising wound, urine and blood were collected aseptically from eligible in- and out-patients for the study and GNB were recovered from the samples using standard bacteriological techniques. The identification of isolated GNB, AST and detection of MBL-producing GNB were done using VITEK®2 COMPACT (Biomerieux) automated system, Modified Kirby Bauer disc diffusion method and IMP+EDTA CDT phenotypic method, respectively. Gram-negative bacterial growth was detected in 135 (77.1%.) cases with Escherichia coli (20.7%), Klebsiella pneumoniae (17.8%) and Burkholderia cepacia (14.1%) being the most preponderant isolates. Urine yielded more GNB, 45.2% than other samples. The isolates were sensitive to gentamicin (63%), imipenem (54.8%), and ofloxacin (46.7%) but showed high resistance to sulfamethoxazole-trimethoprim (78.5%), ceftriaxone (74.1%) and aztreonam (66.7%). The overall prevalence of MDR was 60% with the highest recorded in University of Uyo Teaching Hospital (UUTH), 64.8%. The overall prevalence of MBL producers was 39.3% with H. alvei, M. morgannii, P. mirabilis, R. radiobacter and P. aeruginosa being the majority, mostly from urine samples (47.5%) and UUTH health facility (43.7%). All MBL-producing GNB were MDR strains. Seven strains were pan-drug resistant. A combination of robust antibiotic and MBL screening of drug resistant GNB is essential for effective therapeutic decisions. Also, rational use of antibiotics, review of antibiotic usage policies and increased surveillance of MBL-producing GNB is strongly advocated.

#3139 PREVALENCE OF INFECTIONS ASSOCIATED WITH THE HEMODIALYSIS CATHETER IN MEXICO CITY

Abstract Background and Aims In hemodialysis, intravenous catheter is the most frequent vascular access to begin treatment in patients with chronic kidney disease. Infectious complications are a frequent adverse effect of the vascular access, they may cause vascular access retreat and serious diseases like septic shock, bacterial endocarditis, septic arthritis, venous thromboembolism and death (between 5 and 10%). Leading microorganisms of hemodialysis infection are Gram positive bacteria, while Gram negative are less common. Method Study type and design: Used a descriptive, retrospective, open, observational and analytical cross-sectional study. Sampling type: Non-probabilistic of consecutive cases. Population: Patients diagnosed with CKD 5 KDIGO on renal function replacement therapy with hemodialysis through a temporary or permanent catheter in a private kidney care unit in Mexico City from October 2014 to September 2022. Results We identified 168 cases of CRBSI throughout the 8 years of the study. We found a prevalence of 0.86% for every 100 hemodialysis and a cumulative incidence of 4.97% for every 100 hemodialysis. Leading etiology pathogens of CRBSI in the kidney care unit were Gram negative bacteria (76.8%), mainly Enterobacter cloacae (20.8%), Escherichia coli (13.7%), Stenotrophomonas maltophilia (11.9%) and Burkholderia cepacia (4.2%). We found that 51,8% of the Gram negative CRBSI were due to multiresistant bacteria, which led to 5 directly related deaths. On the other hand, Gram positive bacteria caused 23.2% of CRBSI. Staphylococcus aureus and Staphylococcus epidermidis were the most frequent with 8.9% and 8.3%, respectively, with no related deaths. Conclusion Unlike international literature, in our study, gram negative bacteria were the main agents of CRBSI. The prevalence of CRBSI in our study was high, however, infection directly related mortality remained low. These results led us to investigate the origin of the vascular access infection. In an attempt to reduce the number of CRBSI, we emphasized preventive measures, especially hand hygiene of healthcare professionals within the kidney care unit and with the patient's personal environment at home. We would like to recall that empirical therapy should be based on the results of the kidney care unit microbiology and antibiotic sensitivity, to reduce CRBSI episodes and bacterial resistance.

Repurposing High-Throughput Screening Identifies Unconventional Drugs with Antibacterial and Antibiofilm Activities against Pseudomonas aeruginosa under Experimental Conditions Relevant to Cystic Fibrosis.

Pseudomonas aeruginosa is the most common pathogen infecting cystic fibrosis (CF) lungs, causing acute and chronic infections. Intrinsic and acquired antibiotic resistance allow P. aeruginosa to colonize and persist despite antibiotic treatment, making new therapeutic approaches necessary. Combining high-throughput screening and drug repurposing is an effective way to develop new therapeutic uses for drugs. This study screened a drug library of 3,386 drugs, mostly FDA approved, to identify antimicrobials against P. aeruginosa under physicochemical conditions relevant to CF-infected lungs. Based on the antibacterial activity, assessed spectrophotometrically against the prototype RP73 strain and 10 other CF virulent strains, and the toxic potential evaluated toward CF IB3-1 bronchial epithelial cells, five potential hits were selected for further analysis: the anti-inflammatory and antioxidant ebselen, the anticancer drugs tirapazamine, carmofur, and 5-fluorouracil, and the antifungal tavaborole. A time-kill assay showed that ebselen has the potential to cause rapid and dose-dependent bactericidal activity. The antibiofilm activity was evaluated by viable cell count and crystal violet assays, revealing carmofur and 5-fluorouracil as the most active drugs in preventing biofilm formation regardless of the concentration. In contrast, tirapazamine and tavaborole were the only drugs actively dispersing preformed biofilms. Tavaborole was the most active drug against CF pathogens other than P. aeruginosa, especially against Burkholderia cepacia and Acinetobacter baumannii, while carmofur, ebselen, and tirapazamine were particularly active against Staphylococcus aureus and B. cepacia. Electron microscopy and propidium iodide uptake assay revealed that ebselen, carmofur, and tirapazamine significantly damage cell membranes, with leakage and cytoplasm loss, by increasing membrane permeability. IMPORTANCE Antibiotic resistance makes it urgent to design new strategies for treating pulmonary infections in CF patients. The repurposing approach accelerates drug discovery and development, as the drugs' general pharmacological, pharmacokinetic, and toxicological properties are already well known. In the present study, for the first time, a high-throughput compound library screening was performed under experimental conditions relevant to CF-infected lungs. Among 3,386 drugs screened, the clinically used drugs from outside infection treatment ebselen, tirapazamine, carmofur, 5-fluorouracil, and tavaborole showed, although to different extents, anti-P. aeruginosa activity against planktonic and biofilm cells and broad-spectrum activity against other CF pathogens at concentrations not toxic to bronchial epithelial cells. The mode-of-action studies revealed ebselen, carmofur, and tirapazamine targeted the cell membrane, increasing its permeability with subsequent cell lysis. These drugs are strong candidates for repurposing for treating CF lung P. aeruginosa infections.

The Conformational Transitions and Dynamics of Burkholderia cepacia Lipase Regulated by Water-Oil Interfaces.

Structural dynamics and conformational transitions are crucial for the activities of enzymes. As one of the most widely used industrial biocatalysts, lipase could be activated by the water-oil interfaces. The interface activations were believed to be dominated by the close-to-open transitions of the lid subdomains. However, the detailed mechanism and the roles of structure transitions are still under debate. In this study, the dynamic structures and conformational transitions of Burkholderia cepacia lipase (LipA) were investigated by combining all-atom molecular dynamics simulations, enhanced sampling simulation, and spectrophotometric assay experiments. The conformational transitions between the lid-open and lid-closed states of LipA in aqueous solution are directly observed by the computational simulation methods. The interactions between the hydrophobic residues on the two lid-subdomains are the driven forces for the LipA closing. Meanwhile, the hydrophobic environment provided by the oil interfaces would separate the interactions between the lid-subdomains and promote the structure opening of LipA. Moreover, our studies demonstrate the opening of the lids structure is insufficient to initiate the interfacial activation, providing explanations for the inability of interfacial activation of many lipases with lid structures.

The first report of a rot on Welsh onion (Allium fistulosum L.) caused by Burkholderia cepacia complex bacteria in Akita Prefecture, Japan

The first report of a rot on Welsh onion (Allium fistulosum L.) caused by Burkholderia cepacia complex bacteria in Akita Prefecture, Japan

68Ga]Ga-Ornibactin for Burkholderia cepacia complex Infection Imaging Using Positron Emission Tomography.

Bacteria from the Burkholderia cepacia complex are generally considered to be non-pathogenic to the healthy population. However, some of these species may cause serious nosocomial infections in immunocompromised patients; as such, it is essential to diagnose these infections rapidly so that adequate treatment can be initiated. We report here the use of a radiolabeled siderophore, ornibactin (ORNB), for positron emission tomography imaging. We successfully radiolabeled ORNB with gallium-68 with high radiochemical purity and proved that the resulting complex has optimal in vitro characteristics. In mice, the complex did not show excessive accumulation in organs and was excreted in the urine. We demonstrated that the [68Ga]Ga-ORNB complex accumulates at the site of Burkholderia multivorans infection, including pneumonia, in two animal infection models. These results suggest that [68Ga]Ga-ORNB is a promising tool for the diagnosis, monitoring, and evaluation of the therapeutic response to B. cepacia complex infection.

Analysis of cumulative antibiogram reports in intensive care units at an Egyptian University Hospital

BackgroundInstitutions must have access to antibiograms to monitor changes in antimicrobial resistance and direct empirical antibiotic therapy. The first facility-specific cumulative antibiogram was launched in the ICU in 2019. Consequently, many antibiogram-operation-related actions have been adopted in the institution based on reported data. This study aimed to analyze the cumulative antibiogram reports for multiple intensive care units (ICUs) for 2020, and compare the antimicrobial susceptibility testing (AST) patterns between the 2019 and 2020 years in an academic medical center. MethodsThis cross-sectional study was performed of routine bacterial culture and AST data extracted from a laboratory information system in a 2252-bed capacity hospital. Only the first diagnostic isolate of a given species per patient per year was included in the study. Interpretation and reporting were done in accordance with the applicable Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing guidelines. ResultsOf the 46,791 clinical isolates, the Gram-negative bacilli isolation rate witnessed a significant increase: 35,670 isolates in 2020 versus. 33,652 isolates in 2019. Klebsiella pneumoniae showed a statistically significant increase, mainly in pediatric, emergency, and cardiothoracic ICUs (p < 0.001). Neonatal and pediatric ICUs showed statistically significant increases in Pseudomonas aeruginosa and Proteus mirabilis isolates (p < 0.001). A statistically significant decrease was noted in the prevalence of Acinetobacter, Escherichia coli, Burkholderia cepacia, and Enterobacter cloacae. The sensitivities of K. pneumoniae and E. coli to imipenem and tigecycline significantly improved (p < 0.001). The sensitivity to colistin was significantly decreased (p < 0.001). The sensitivity of P. aeruginosa isolates to colistin and carbapenems was improved (p < 0.001). We reported a statistically significant decrease in all Gram-positive cocci (11,121 in 2020 versus. 11,528 in 2019). Staphylococcus aureus showed a statistically significant increase (p < 0.001), particularly in the medical ICU. ConclusionThe high susceptibility rates of Enterobacteriaceae toward colistin and tigecycline, should be cautiously considered in empiric therapy while looking for alternatives. The majority of isolates of Gram-positive cocci were coagulase negative staphylococci (CONS), we still need to confirm whether they are true pathogens or commensals before considering anti-staphylococcal agents in the empirical therapy. We underscored some corrective actions that might have improved the susceptibility rates, such as antibiotic cycling

Identification by Reverse Vaccinology of Three Virulence Factors in Burkholderia cenocepacia That May Represent Ideal Vaccine Antigens.

The Burkholderia cepacia complex comprises environmental and clinical Gram-negative bacteria that infect particularly debilitated people, such as those with cystic fibrosis. Their high level of antibiotic resistance makes empirical treatments often ineffective, increasing the risk of worst outcomes and the diffusion of multi-drug resistance. However, the discovery of new antibiotics is not trivial, so an alternative can be the use of vaccination. Here, the reverse vaccinology approach has been used to identify antigen candidates, obtaining a short-list of 24 proteins. The localization and different aspects of virulence were investigated for three of them-BCAL1524, BCAM0949, and BCAS0335. The three antigens were localized in the outer membrane vesicles confirming that they are surface exposed. We showed that BCAL1524, a collagen-like protein, promotes bacteria auto-aggregation and plays an important role in virulence, in the Galleria mellonella model. BCAM0949, an extracellular lipase, mediates piperacillin resistance, biofilm formation in Luria Bertani and artificial sputum medium, rhamnolipid production, and swimming motility; its predicted lipolytic activity was also experimentally confirmed. BCAS0335, a trimeric adhesin, promotes minocycline resistance, biofilm organization in LB, and virulence in G. mellonella. Their important role in virulence necessitates further investigations to shed light on the usefulness of these proteins as antigen candidates.

Propidium Monoazide (PMAxx)-Recombinase Polymerase Amplification Exo (RPA Exo) Assay for Rapid Detection of Burkholderia cepacia Complex in Chlorhexidine Gluconate (CHX) and Benzalkonium Chloride (BZK) Solutions.

Both sterile and non-sterile pharmaceutical products, which include antiseptics, have been recalled due to Burkholderia cepacia complex (BCC) contamination. Therefore, minimizing the frequency of outbreaks may be conducive to the development of a quick and sensitive approach that can distinguish between live and dead loads of BCC. We have assessed an exo probe-based recombinase polymerase amplification (RPA) with 10 µM propidium monoazide (PMAxx) for selective detection of live/dead BCC cells in various concentrations of antiseptics (i.e., chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions) after 24 h. The optimized assay conducted using a set of primer-probes targeting gbpT was performed at 40 °C for 20 min and shows a detection limit of 10 pg/µL of genomic DNA from B. cenocepacia J2315, equivalent to 104 colony-forming units (CFU/mL). The specificity of a newly designed primer and probe was 80% (20 negatives out of 25). The readings for total cells (i.e., without PMAxx) from 200 µg/mL CHX using PMAxx-RPA exo assay was 310 relative fluorescence units (RFU), compared to 129 RFU with PMAxx (i.e., live cells). Furthermore, in 50-500 µg/mL BZK-treated cells, a difference in the detection rate was observed between the PMAxx-RPA exo assay in live cells (130.4-459.3 RFU) and total cells (207.82-684.5 RFU). This study shows that the PMAxx-RPA exo assay appears to be a valid tool for the simple, rapid and presumptive detection of live BCC cells in antiseptics, thereby ensuring the quality and safety of pharmaceutical products.

Burkholderia cepacia infections at sites other than the respiratory tract: A large case series from a tertiary hospital in Madurai

Sparsely reported extrapulmonary Burkholderia cepacia complex (Bcc) infections highlights the importance of this study. This was a retrospective chart review of 37 patients with extrapulmonary Bcc infections admitted between December 2019 and July 2022 in a tertiary hospital. Males accounted for 70% of cases. 78% had atleast one underlying comorbid illness. Among 37 isolates, 22 were from blood, others include exudates, urine and peritoneal fluid. Susceptibility rates of ceftazidime, meropenem, minocycline, cotrimoxazole and levofloxacin were 88, 88, 70, 65.7 and 56.7% respectively. Eleven died of septic shock and 24 patients (64.8%) had good outcomes, while two were lost to followup.

Mixed bacterial-viral lung infections in patients with cystic fibrosis

The main cause of death in patients with cystic fibrosis (CF) is infectious process in the lungs, in particular, chronic lung infections caused by various pathogens, most often a combination of bacteria, fungi, or viruses. Data on mixed bacterial and viral-bacterial infections from domestic and foreign sources are fragmentary and sparse. The dominant associations of bacterial and viral pathogens in patients with cystic fibrosis have not been studied properly, and data on their epidemiological significance are lacking. The aim of this study was to assess the prevalence of bacterial and viral infections in patients with cystic fibrosis and to substantiate the need for the development of virological monitoring. Methods. Biomaterials from the respiratory tract of CF patients (409 children and 160 adults with CF) examined from 2006 to 2022 were used. The study was carried out using bacteriological methods, molecular genetic methods (RT-PCR) and MALDI-TOF mass-spectrometry. Results. Microflora of the respiratory tract was shown to be mixed in 2/3 patients with CF. The microflora of the lungs of children with CF is a dynamic community of microorganisms with high diversity and variability. In adult patients, associations of microorganisms are more common than in children, but the composition of associations is less diverse. We isolated about 40 species of bacteria from adult patients and more than 85 species from children in our sample. NFMO prevailed, including Burkholderia cepacia complex, Pseudomonas aeruginosa, Achromobacter xylosoxidans, Achromobacter ruhlandii, Stenotrophomonas maltophilia, and Staphylococcus aureus, Candida albicans, Aspergillus spp. Real-time PCR showed the presence of rhinovirus RNA in 10% of samples obtained from children and 12.9% from adults with cystic fibrosis. Conclusion. Our results indicate the need for continuous monitoring of the lung microflora in patients with CF, including testing for viruses.