Diagnostic methods and identification challenges experienced in a Burkholderia contaminans outbreak occurred in a tertiary care centre

Species distribution and antimicrobial susceptibility of Burkholderia cepacia complex isolates in clinical infections: Experience from a tertiary care hospital, Southern India

PURPOSE

Burkholderia cepacia complex (Bcc) is a diverse group of environmental bacteria associated with opportunistic infections. The identification of Bcc using conventional methods poses challenges. Bcc infections are difficult to treat due to intrinsic antibiotic resistance. The study aimed to investigate the species distribution and antimicrobial susceptibility of clinical Bcc isolates.

METHODS

A total of 153 Bcc isolates obtained from clinical samples were analysed. Species identification was carried out using automated methods, including MALDI-TOF MS and VITEK2. Antimicrobial susceptibility testing was performed using the disc diffusion method.

RESULTS

Burkholderia cenocepacia (70.5%) emerged as the most prevalent species, followed by Burkholderia contaminans (9.8%) and Burkholderia cepacia (7.2%). Ventilator-associated pneumonia (38.6%) was the most common infection, followed by sepsis (28.1%). Co-existence of Bcc with other pathogens in many cases suggested potential co-infection scenarios. Antimicrobial susceptibility revealed that ceftazidime, co-trimoxazole and meropenem were the most effective drugs, while levofloxacin proved to be the least effective. Moderate susceptibility was noted to minocycline, with 4.6% of isolates exhibiting multi-drug resistance.

CONCLUSION

This study provides valuable insights into the prevalence, clinical associations, and antibiotic susceptibility of Bcc in India. It highlights the importance of Bcc as a nosocomial pathogen, especially in vulnerable patient populations. The findings contribute to understanding Bcc infections, their distribution, and emphasize the necessity for accurate identification methods in clinical settings.

Two consecutive outbreaks caused by chlorhexidine mouthwash contaminated with Burkholderia contaminans in a two-hospital tertiary care system

BACKGROUND

Hospital outbreaks caused by Burkholderia spp. have been linked to contamination of several medical solutions and products and are frequently associated with delayed detection and high mortality.

AIM

To describe the management of two consecutive Burkholderia contaminans outbreaks caused by contaminated mouthwash of different brands during the COVID-19 pandemic.

METHODS

This was a retrospective cohort study of all patients involved in two outbreaks caused by B. contaminans detected in 2021 and 2022. The investigation was initiated after a cluster of positive respiratory specimens, followed by retrospective and prospective case-finding.

FINDINGS

A total of 69 patients were affected, 47 in 2021 and 22 in 2022. The majority of affected patients had positive respiratory specimens (85.5%); 55.1% of cases had COVID-19, and 72.5% had multidrug-resistant organisms. Almost all (97.1%) patients required ventilation and 42.0% died. Seventeen percent of cases in the first outbreak were deemed to have been acquired by patient-to-patient transmission, whereas all of the cases in the second outbreak were infected directly from using mouthwash. The experience gained from the first outbreak and the formation of a multidisciplinary Infection Control Rapid Response Team resulted in more rapid recognition and control of the second outbreak. Multivariate analysis showed that older age, intensive care unit admission, and COVID-19 infection were independent predictors of mortality.

CONCLUSION

Burkholderia outbreaks at the time of COVID-19 were associated with high mortality. Rapid detection and response by a dedicated experienced team (as in the second outbreak) can reduce mortality and prevent superimposed cross-transmission between patients.

Induction of Resistance of Antagonistic Bacterium Burkholderia contaminans to Postharvest Botrytis cinerea in Rosa vinifera

In order to study the problem that grapes are vulnerable to microbial infection and decay during storage, a method based on antagonistic Burkholderia contaminans against postharvest Botrytis cinerea of Rosa vinifera was proposed in this paper. The method tested the resistance induction mechanism of Botrytis cinerea after harvest and determined the fruit decay rate treated by antagonistic Burkholderia contaminans. The results showed that the antagonistic bacterium B-1 had bacteriostatic effect on many common pathogens of fruits and vegetables to a certain extent, and the bacteriostatic range was wide. Among them, the inhibition rate of Fusarium moniliforme was 75.5% and that of Botrytis cinerea was 51.2%. After testing, it can be found that antagonistic bacteria have an inhibitory effect on pathogenic fungi and have an effect on phenylpropane metabolic pathway, reactive oxygen species metabolic pathway, and the activities of other resistance-related enzymes. Through comparison, it can be found that the antagonistic Burkholderia contaminans has a strong antibacterial mechanism against Botrytis cinerea of rose grape after harvest. The fruit treated with antagonistic B Burkholderia B-1 has significantly reduced the decay rate and increased the activity of antibacterial active protein.