Abstract

Background: Peritoneal Dialysis (PD) related peritonitis remains a major cause of morbidity, hospitalization, and technique failure. Local microbiological surveillance is essential to guide empirical antimicrobial therapy, particularly in underrepresented regions.

Methods: We conducted a retrospective, descriptive study including all PD-related peritonitis episodes occurring between November 2023 and January 2024 at a tertiary referral hospital in the Dominican Republic. Microbiological findings from peritoneal effluent cultures, descriptive antibiotic susceptibility patterns, recurrence, hospitalization, and clinical outcomes were analyzed.

Results: Thirty peritonitis episodes were identified among 307 patients enrolled in the PD program, corresponding to an estimated peritonitis rate of 0.39 episodes per patient-year. Episodes occurred more frequently in male patients, and the most affected age group was 51-65 years. Staphylococcus aureus was the most frequently isolated microorganism, followed by Pseudomonas aeruginosa and Acinetobacter baumannii. Ten episodes were culture-negative, and four were polymicrobial (4/30 episodes). Polymicrobial peritonitis involved clinically relevant microorganism combinations and included the only case with multiple recurrences. Gram-positive organisms showed susceptibility mainly to vancomycin and amikacin, while Gram-negative organisms demonstrated predominant susceptibility to meropenem. Six patients required transition to hemodialysis, and two deaths occurred due to septic shock.

Conclusion: Staphylococcus aureus remains the leading cause of PD-related peritonitis in our center, with a significant contribution from Gramnegative organisms. Polymicrobial and culture-negative peritonitis episodes were clinically relevant and associated with a more complicated course. These findings highlight the importance of continuous local microbiological surveillance, optimized diagnostic practices, and targeted infection prevention strategies to improve outcomes and preserve PD technique survival.

Keywords

Peritoneal dialysis; Peritonitis; Chronic kidney disease; Microbiology; Antibiotic susceptibility; Caribbean

Introduction

Peritoneal Dialysis (PD) is an established renal replacement therapy that preserves residual kidney function and provides home-based flexibility for patients with end-stage kidney disease. Despite these advantages, infectious complications-particularly PD-related peritonitis-remain a major limitation and a leading cause of hospitalization, catheter loss, technique failure, and mortality. The International Society for Peritoneal Dialysis (ISPD) recommends maintaining peritonitis rates below 0.5 episodes per patient-year; however, reported rates and causative organisms vary substantially across centers and regions, influenced by local practices, microbiological processing, and patient-related factors.

Local microbiological surveillance is essential to inform empirical antimicrobial therapy and support infection prevention strategies. This is particularly relevant in underrepresented regions such as the Caribbean, where published data on the microbiological profile of PD-related peritonitis remain limited. In addition, a high frequency of culture-negative peritonitis has been reported in multiple settings and may reflect prior antibiotic exposure, pre-analytical handling issues, or limitations in conventional microbiological techniques, all of which can hinder organism-directed therapy.

The aim of this study was to describe the microbiological profile of PD-related peritonitis episodes, summarize antibiotic susceptibility patterns as reported in routine microbiology results, and describe selected clinical outcomes, including mortality and transition to hemodialysis, in a tertiary referral hospital in the Dominican Republic during a defined 3-month surveillance period.

Methods

Study design and setting

We conducted a retrospective, descriptive, cross-sectional study at the Department of Nephrology of Hospital Regional Universitario José María Cabral y Báez, a tertiary referral center in Santiago, Dominican Republic. The study period was limited to three months (November 2023 to January 2024) because complete and consistently documented microbiological and clinical outcome data were available for systematic retrieval during this interval, allowing standardized case capture and reliable descriptive analysis within the Peritoneal Dialysis (PD) program.

Study population and sample

All patients undergoing chronic peritoneal dialysis who experienced at least one episode of PD-related peritonitis between November 2023 and January 2024 were eligible. During the study period, the PD program consisted of a stable cohort of 307 patients. The analytical sample comprised 30 PD-related peritonitis episodes identified during the study interval. Episodes were analyzed at the episode level. If a patient experienced more than one episode during the study period, each episode was considered a separate analytical unit.

Case definition

Peritonitis was defined according to clinical and laboratory criteria, including the presence of compatible symptoms (abdominal pain and/ or cloudy peritoneal effluent) associated with an elevated peritoneal effluent leukocyte count and/or a positive peritoneal effluent culture. Interpretation of peritoneal effluent leukocyte counts followed institutional practice aligned with International Society for Peritoneal Dialysis (ISPD) diagnostic criteria.

Sample collection and microbiological analysis

Peritoneal effluent samples were collected under sterile conditions at the time of clinical suspicion of peritonitis and promptly transported to the microbiology laboratory. Conventional culture techniques were performed according to institutional protocols. Culture-negative peritonitis was defined as the absence of microbial growth despite fulfilment of clinical and cytological diagnostic criteria. Polymicrobial peritonitis was defined as the isolation of two or more microorganisms from the same peritoneal effluent sample.

Peritoneal dialysis modality and catheter management

All patients were receiving chronic peritoneal dialysis at the time of infection. Peritonitis episodes were counted as separate events when they met diagnostic criteria during the study period, regardless of recurrence. Catheter manipulation and exchange procedures followed routine institutional practices.

Data collection

Data were collected retrospectively using a structured data collection form specifically designed for this study. Information was extracted from institutional medical records and microbiology laboratory reports and systematically recorded in a spreadsheet-based database (Microsoft Excel). For each peritonitis episode, the following variables were collected: demographic data (age and sex), documented comorbidities (hypertension and diabetes mellitus), microbiological findings from peritoneal effluent cultures (including culture-negative results), and antibiotic susceptibility results as reported in routine microbiology records. Clinical outcome variables included recurrence pattern, length of hospital stay, need for transition to hemodialysis, and in-hospital mortality. All data were anonymized prior to analysis. When a variable was not documented in the source record, it was considered missing and no imputation was performed.

Statistical analysis

All analyses were descriptive. Categorical variables are presented as absolute frequencies (counts). Antibiotic susceptibility was summarized descriptively by microorganism based on routine microbiology reports; organism-specific susceptibility percentages were not calculated due to the limited number of isolates per microorganism and the retrospective nature of the study. Peritonitis burden was reported as a program-based proportion and as an estimated peritonitis rate expressed as episodes per patient-year, extrapolated from the 3-month observation period under the assumption of a stable cohort. Data management and descriptive statistical analyses were performed using Microsoft Excel and IBM SPSS Statistics (version XX).

Ethical considerations

This study used retrospective, de-identified data derived from routine clinical care. Institutional approval was obtained from the Ethics Committee / Institutional Review Board of Hospital Regional Universitario José María Cabral y Báez (Approval No. HRUJMCB202601). Given the retrospective nature of the study and the use of anonymized data, the requirement for informed consent was waived.

Results

During the 3-month study period, 30 episodes of peritoneal dialysis–related peritonitis were identified among 307 patients enrolled in the peritoneal dialysis program, corresponding to a programbased proportion of 9.8%. Assuming a stable cohort throughout the observation period, the estimated peritonitis rate was 0.39 episodes per patient-year [1-4].

Demographic characteristics

Peritonitis episodes occurred more frequently in male patients, accounting for 20 episodes, while 10 episodes occurred in female patients. The most affected age group was 51-65 years, followed by the 41-50-year age group (Table 1).

Variable	Category	Episodes
Sex	Male	20
	Female	10
Age group (years)	31–40	2
	41–50	8
	51–65	16
	>65	4

Table 1: Demographic characteristics of PD-related peritonitis episodes (N = 30).
This table summarizes the distribution of peritonitis episodes according to sex and age group among patients receiving peritoneal dialysis during the study period.

Antecedent comorbidities

The most frequent comorbid condition among patients with peritonitis was the coexistence of hypertension and diabetes, observed in 14 episodes. Hypertension as a single comorbidity was also common, while diabetes mellitus alone was less frequently reported (Table 2).

Comorbidity	Episodes
Hypertension + diabetes	14
Hypertension alone	14
Diabetes alone	2

Table 2: Antecedent comorbidities among PD-related peritonitis episodes (N = 30).
This table describes the most frequent comorbid conditions present at the time of peritonitis, including hypertension and diabetes, either alone or in combination.

Microbiological findings

The most frequently isolated microorganism was Staphylococcus aureus, identified in six episodes, followed by Pseudomonas aeruginosa in five episodes and Acinetobacter baumannii in four episodes. Other organisms were less frequently isolated, including Klebsiella pneumoniae, Escherichia coli, and Candida spp., as well as Enterobacter cloacae, Enterococcus faecalis, Enterobacter aerogenes, and Haemophilus spp. ten episodes fulfilled clinical and cytological diagnostic criteria for peritonitis but showed no microbial growth on culture and were classified as culture-negative peritonitis (Table 3).

Microorganism	Episodes
Staphylococcusaureus	6
Pseudomonas aeruginosa	5
Acinetobacterbaumannii	4
Klebsiellapneumoniae	2
Escherichia coli	2
Candida spp.	2
Enterobactercloacae	1
Enterococcusfaecalis	1
Enterobacteraerogenes	1
Haemophilus spp.	1
Culture-negative	10

Table 3: Microorganisms isolated from peritoneal fluid cultures (N = 30).
Microbiological results are reported per episode. The total number of isolated microorganisms exceeds the number of episodes because some episodes were polymicrobial, while others were culture-negative.

Polymicrobial peritonitis

Polymicrobial peritonitis was identified in four episodes (4/30 episodes). The microorganisms involved included combinations of Enterobacter aerogenes with Acinetobacter baumannii and Haemophilus spp., Staphylococcus aureus with Pseudomonas aeruginosa, Staphylococcus aureus with Enterobacter cloacae, and Staphylococcus aureus with Candida spp (Table 4).

Episode	Microorganisms Isolated
1	Enterobacteraerogenes+ Acinetobacter baumannii + Haemophilus spp.
2	Staphylococcusaureus + Pseudomonas aeruginosa
3	Staphylococcusaureus+ Enterobacter cloacae
4	Staphylococcusaureus + Candida spp.

Table 4: Polymicrobial peritonitis episodes and isolated microorganisms (N = 4).
This table details the specific microorganism combinations identified in episodes of polymicrobial peritonitis.

Recurrence of peritonitis

Most episodes presented with one or two recurrences. Among polymicrobial peritonitis episodes, three cases had a single recurrence, while one episode was associated with three or more recurrences (Table 5).

Infection type	Recurrence pattern
Non-polymicrobial	Predominantly 1–2 recurrences
Polymicrobial	3 episodes with 1 recurrence; 1 episode with ≥ 3 recurrences

Table 5: Recurrence of peritonitis according to infection type.
Recurrence patterns are described for polymicrobial and nonpolymicrobial peritonitis episodes during the study period.

Hospital stay and clinical outcomes

Hospitalization was required in the majority of episodes. A substantial proportion of patients experienced prolonged hospital stays, particularly durations between 6 and 10 days and stays longer than 21 days. Six patients required transition to hemodialysis due to peritonitis. Two deaths occurred during the study period, both secondary to septic shock (Table 6).

Variable	Category	Episodes
Length of stay (days)	6–10	8
	>21	8
	Other durations	14
Clinical outcome	Transition to hemodialysis	6
	Mortality	2
	Continued pd	22

Table 6: Length of hospital stay and clinical outcomes of peritoneal dialysis–related peritonitis episodes (N =30).
This table summarizes hospitalization duration, modality switch to hemodialysis, mortality, and continuation of peritoneal dialysis after treatment.

Antibiotic susceptibility

Antibiotic susceptibility was summarized descriptively according to the isolated microorganisms. Gram-positive organisms, predominantly Staphylococcus aureus and Enterococcus faecalis, showed susceptibility mainly to vancomycin and amikacin. Gram-negative organisms demonstrated predominant susceptibility to meropenem, while Pseudomonas aeruginosa also showed susceptibility to amikacin. Antifungal therapy was required in episodes involving Candida spp. Given the limited number of isolates per microorganism and the retrospective nature of the data, susceptibility findings are presented descriptively rather than as organism-specific percentages (Table 7).

Microorganism	Antibiotics with reported susceptibility
Staphylococcusaureus	Vancomycin, amikacin
Pseudomonas aeruginosa	Meropenem, amikacin
Acinetobacterbaumannii	Meropenem
Klebsiellapneumoniae	Meropenem
Escherichia coli	Meropenem
Enterobactercloacae	Meropenem
Enterobacteraerogenes	Meropenem
Enterococcusfaecalis	Vancomycin
Candida spp.	Antifungal therapy
Haemophilus spp.	Ciprofloxacin

Table 7: Isolated microorganisms and antibiotics with reported susceptibility in PD-related peritonitis episodes.

Discussion

Peritoneal dialysis-related peritonitis remains a major complication in patients undergoing chronic peritoneal dialysis and continues to be a leading cause of hospitalization, technique failure, and mortality. In this single-center study conducted at a tertiary referral hospital in the Dominican Republic, we describe the microbiological profile, descriptive antibiotic susceptibility patterns, and clinical outcomes of peritonitis episodes during a defined surveillance period, providing local data from an underrepresented Caribbean population.

Consistent with previous reports, Staphylococcus aureus was the most frequently isolated microorganism in our cohort. The predominance of S. aureus has been widely attributed to skin or catheter-related contamination, including exit-site colonization and touch contamination during dialysis exchanges. These findings reinforce the importance of continuous patient education, meticulous exit-site care, and strict adherence to aseptic technique as essential preventive strategies in peritoneal dialysis programs.

Gram-negative organisms, particularly Pseudomonas aeruginosa and Acinetobacter baumannii, represented a substantial proportion of isolates. These pathogens are commonly associated with environmental contamination, biofilm formation on peritoneal dialysis catheters, and healthcare-associated exposure, especially in tertiary care settings.

Their presence underscores the need for robust infection control measures, regular review of environmental hygiene, and strict procedural protocols to reduce the risk of infection.

Polymicrobial peritonitis accounted for a minority of episodes (4/30) in our cohort but involved clinically relevant combinations of microorganisms, including Gram-negative bacilli and, in one case, fungal infection. The presence of polymicrobial infections, particularly those involving Staphylococcus aureus in combination with Gramnegative organisms or Candida spp., is clinically significant, as previous studies have associated these patterns with increased disease complexity and recurrence. In our cohort, polymicrobial episodes included the only case with multiple recurrences, suggesting a more challenging clinical course that may require closer monitoring and more aggressive management strategies.

A notable proportion of peritonitis episodes were culture-negative despite fulfilling clinical and cytological diagnostic criteria. Culturenegative peritonitis remains a recognized challenge in peritoneal dialysis programs worldwide and may result from prior antibiotic exposure, delays in specimen processing, or limitations in conventional microbiological techniques. This finding highlights the need to strengthen pre-analytical procedures, optimize sample handling, and consider the implementation of improved diagnostic strategies to enhance microorganism recovery and guide targeted therapy.

Antibiotic susceptibility was reported descriptively by microorganism due to the limited number of isolates per pathogen. Gram-positive organisms demonstrated susceptibility mainly to vancomycin and amikacin, while Gram-negative organisms showed predominant susceptibility to meropenem, with Pseudomonas aeruginosa also susceptible to amikacin. These findings support the continued use of locally informed empirical antibiotic regimens while emphasizing the importance of ongoing microbiological surveillance to detect emerging resistance patterns and guide periodic protocol updates.

A substantial proportion of peritonitis episodes required hospitalization, and prolonged hospital stays were frequently observed. Although detailed episode-level comparisons were not performed, prolonged hospitalization likely reflects disease severity, the need for intravenous antimicrobial therapy, and complications related to Gramnegative or polymicrobial infections. These observations underscore the significant clinical burden of peritoneal dialysis-related peritonitis and the importance of early diagnosis, timely initiation of appropriate therapy, and continuous evaluation of local management protocols.

Overall, this study provides valuable insight into the microbiological characteristics and clinical impact of peritoneal dialysis–related peritonitis in our institution. The findings highlight the ongoing predominance of Staphylococcus aureus, the important contribution of Gram-negative organisms, and the clinical relevance of polymicrobial and culture-negative episodes. These observations support the need for continuous local microbiological surveillance, strengthened diagnostic practices, and targeted infection prevention strategies to improve patient outcomes and preserve peritoneal dialysis technique survival.

Limitations

This study has several limitations. Its retrospective design and singlecenter setting limit the generalizability of the findings. The relatively small number of peritonitis episodes and the short observation period preclude robust risk factor analysis and causal inference. The three-month surveillance interval was selected because complete and consistently documented microbiological and clinical outcome data were available for systematic retrieval during this period. In addition, episode-level length-of-stay data were not available for detailed comparative analysis. Organism-specific antibiotic susceptibility data were not consistently available, which limited the construction of a microorganism-level antibiogram. Despite these limitations, the study provides relevant local epidemiological data from an underrepresented Caribbean population and offers valuable insight to guide empirical therapy and infection prevention strategies.

Conclusion

Peritoneal dialysis–related peritonitis remains a major complication in our center. Staphylococcus aureus was the most frequently isolated microorganism, and Gram-negative pathogens contributed substantially to disease burden. Polymicrobial and culture-negative peritonitis episodes were clinically relevant and associated with a more complicated course, including recurrence and technique failure. These findings highlight the importance of continuous local microbiological surveillance, optimization of diagnostic procedures, and reinforcement of infection prevention measures to improve outcomes and preserve peritoneal dialysis technique survival.

Declarations

Ethics approval and consent to participate

This study was approved by the Ethics Committee/Institutional Review Board of Hospital Regional Universitario José María Cabral y Báez (Approval No. HRUJMCB202601). Given the retrospective nature of the study and the use of de-identified data, the requirement for informed consent was waived.

Consent for publication

Not applicable.

Availability of data and materials

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Competing interests

The authors declare that they have no competing interests.

Funding

This research received no external funding.

Authors’ contributions

KR conceived the study. KR, YC, AD, AV, GA, and DT contributed to data collection and manuscript drafting. All authors reviewed and approved the final manuscript.

Acknowledgements

The authors thank the nursing staff and microbiology laboratory personnel of Hospital Regional Universitario José María Cabral y Báez for their support in patient care and data collection.

References

1. Al Sahlawi M, Perl J (2022) Peritoneal dialysis peritonitis outcomes: getting to the heart of the matter. Kidney Int Rep 7: 2329-2331. [Ref.]
2. Salzer WL (2018) Peritoneal dialysis-related peritonitis: challenges and solutions. Int J Nephrol Renovasc Dis 11: 173-186. [Ref.]
3. De la Espada Piña V, Quirós Ganga PL, Gil Junquero JM, Aresté Fosalba N, Fernández Girón F, et al. (2021) Two decades of peritonitis analysis in peritoneal dialysis: epidemiological, clinical, microbiological and outcome aspects. Nefrologia 41: 417-425. [Ref.]
4. Portolés Pérez J, García E, Janeiro D, Sánchez Álvarez JE (2023) Peritonitis associated with peritoneal dialysis. Nefrología al Día. [Ref.]

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Article Information

Article Type: RESEARCH ARTICLE

Citation: Ramos K, Cosme Y, Durán A, Zorrilla J, Veras A, et al. (2026) Microbiological Profile and Antibiotic Susceptibility of Peritoneal DialysisRelated Peritonitis in a Tertiary Hospital in the Dominican Republic. Int J Nephrol Kidney Fail 12(2): dx.doi.org/10.16966/2380-5498.264

Copyright: © 2026 Ramos K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication history: 

Received date: 11 Jan, 2026

Accepted date: 02 Feb, 2026

Published date: 10 Feb, 2026