Assessing the Impact of Burkholderia cepacia in Critical Care: Insights into Clinical Outcomes, Resistance Patterns, and Contamination Sources

• Enhanced surveillance and screening for B. cepacia, particularly in high-risk patients with diabetes or prolonged ICU stays.
• Tailored antibiotic therapy based on local susceptibility patterns, with consideration of ciprofloxacin and trimethoprim/sulfamethoxazole as potential first-line options.
• Stringent infection control measures, including strict hand hygiene, proper disinfection of medical equipment, and regular environmental sampling.

Contaminated medical equipment, intravenous fluids, and environmental reservoirs within hospitals have been implicated in outbreaks [10,11]. A 2020 case series by Bharara et al. highlighted the potential for B. cepacia to cause outbreaks in neonatal intensive care units, underscoring the vulnerability of certain patient populations [12]. Vulnerable groups; including those undergoing chemotherapy, organ transplants, or using immunosuppressive drugs, are at higher risk, with neonates and geriatrics being particularly susceptible [13]. Understanding B. cepacia's pathogenicity is crucial. Surface structures such as pili, flagella, and adhesins facilitate its adherence to host cells, promoting colonization in various body sites [14]. Biofilm formation, enabled by exopolysaccharides like cepacian, plays a pivotal role in chronic infections, particularly in cystic fibrosis patients [15]. B. cepacia secretes virulence factors such as proteases, lipases, and phospholipases that contribute to tissue damage and immune evasion, making it a formidable pathogen [16]. The treatment of B. cepacia infections is complicated by its intrinsic and acquired resistance to multiple classes of antibiotics [14,15]. Efflux pumps, enzymatic degradation, and alterations in target sites contribute to its multidrug resistance. This necessitates a tailored approach based on antimicrobial susceptibility testing [17]. However, the limited treatment options underscore the importance of antimicrobial stewardship and the urgent need for alternative therapeutic strategies.

Table 1: This table shows the prevalence of key risk factors among the 25 patients with B. cepacia infections in our study.

Our study provides valuable insights into the clinical profile, antibiotic susceptibility patterns, and outcomes of B. cepacia infections in a tertiary care setting in Delhi. The findings have important implications for clinical practice and infection control.

The prevalence of underlying conditions in our study, particularly diabetes mellitus (44%) and hypertension (40%), aligns with recent studies. For instance, Bhat et al. (2021) reported a significant association between B. cepacia infections and diabetes mellitus in their case series [17]. Our findings reinforce the vulnerability of patients with chronic conditions to opportunistic pathogens like B. cepacia.

The antibiotic susceptibility patterns observed in our study are concerning, particularly the high resistance to cefoperazone + sulbactam (92%). This is higher than the rates reported by Bharara et al. (2020) in their neonatal ICU outbreak investigation, where resistance to cephalosporins ranged from 60-80% [12]. However, our findings of high susceptibility to ciprofloxacin (88%) and trimethoprim/sulfamethoxazole (88%) are more encouraging and consistent with the study by Devanga Ragupathi and Veeraraghavan [9].

The mortality rate of 40% in our study is concerning but comparable to other recent reports. Bilgin et al. (2021) reported a mortality rate of 33% in their outbreak investigation, while Gangaram et al. (2020) observed a mortality rate of 45% in their ICU-based study [6,11]. Despite conducting extensive environmental sampling, encompassing over 200 samples from various sources in the critical care unit, we were unable to identify the specific source of Burkholderia cepacia contamination during the study period. This is a common challenge faced in outbreak investigations, where the environmental reservoir harboring the pathogen may not be readily apparent [18]. As highlighted in the outbreak investigation literature, several factors can contribute to the difficulty in tracing the source of Burkholderia infections:

1. Persistence in the Environment: Burkholderia species are known to survive and persist in a wide range of environmental niches, from water sources to medical equipment. Their ability to form biofilms further enhances their environmental resilience, making them difficult to eradicate.
2. Versatile Transmission Pathways: Burkholderia can be transmitted through multiple routes, including contaminated medical devices, intravenous solutions, respiratory equipment, and even person-to-person spread. The complex interplay of these transmission modes can obscure the primary source.

These findings collectively underscore the significant threat posed by B. cepacia infections in critical care settings.

Limitations of the Study

Several limitations should be considered when interpreting our results:

• Small sample size: With only 25 patients, our statistical power is limited, and some associations may not have reached significance due to type II error.
• Single-center study: Our findings may not be generalizable to other settings or geographical regions.
• Retrospective design: This limits our ability to establish causal relationships and may introduce bias due to missing data or inconsistencies in documentation.
• Lack of molecular typing: We were unable to perform genetic analysis to determine the clonality of the isolates, which could have provided insights into potential transmission patterns.
• Unidentified environmental source: Despite extensive sampling, we could not pinpoint the source of B. cepacia, highlighting the challenges in controlling this pathogen in healthcare settings.

Future studies with larger sample sizes, multi-center designs, and molecular typing methods are needed to further elucidate the epidemiology and clinical impact of B. cepacia infections in critical care settings.

CONCLUSION:

The clinical and epidemiological characteristics of Burkholderia cepacia infections in critical care patients are clarified by our investigation. Our study highlights three key findings:

• High prevalence of underlying conditions: Diabetes mellitus (44%) and hypertension (40%) were common comorbidities, emphasizing the vulnerability of patients with chronic diseases to B. cepacia infections.
• Alarming antibiotic resistance patterns: We observed high resistance rates to cefoperazone + sulbactam (92%) and ceftazidime (48%), while ciprofloxacin and trimethoprim/sulfamethoxazole showed better efficacy (88%) susceptibility each.
• Significant mortality rate: The 40% mortality rate underscores the severity of B. cepacia infections in critical care settings.

These findings have important implications for clinical practice and infection control:

• They emphasize the need for enhanced surveillance and screening for B. cepacia, particularly in high-risk patients.
• They guide empiric antibiotic therapy, suggesting the potential use of ciprofloxacin or trimethoprim/sulfamethoxazole as first-line options, pending susceptibility results.

They highlight the urgent need for stringent infection control measures to prevent the spread of B. cepacia in healthcare settings.

In conclusion, our study provides valuable insights into the challenges posed by B. cepacia infections in critical care units. To tackle this ongoing threat and protect vulnerable patients, future research should focus on identifying environmental reservoirs, developing rapid diagnostic methods, and exploring novel therapeutic approaches. A multidisciplinary approach involving microbiologists, infectious disease specialists, and critical care teams is crucial for optimal management of B. cepacia infections and improvement of patient outcomes.

Acknowledgments: None

Ethical considerations: This study was conducted as part of routine infection control and surveillance activities in our hospital. As it involved retrospective analysis of routinely collected, anonymized clinical and microbiological data, with no additional interventions or patient contact, formal ethical approval was not required as per our institutional guidelines.

Author Contributions:

Author contribution: We declare that all listed authors have made substantial contributions to all of the following three parts of the manuscript:

- research design, or acquisition, analysis, or interpretation of data;

- drafting the paper or revising it critically;

- approving the submitted version.

We also declare that no one who qualifies for authorship has been excluded from the list of authors.

Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conflict of interest: The authors declare no potential conflict of interest