METHODS: A retrospective record review of all CAPD patients on follow-up at the Miri Hospital, Sarawak, Malaysia from 2014 until 2017 was done.
RESULTS AND DISCUSSION: During the 4-year period, the overall peritonitis rate was 0.184 episodes per patient-year. Gram-positive and gram-negative bacteria each constituted one-third of the peritonitis; fungi (2.6%), Mycobacterium tuberculosis (MTB) (5.3%), polymicrobial (2.6%) and sterile culture (26.3%). The most commonly isolated gram-positive bacteria were coagulase-negative Staphylococcus. Our peritonitis rate is comparable to that of other centres i.e., Japan 0.195 and Indonesia 0.25. In comparison, countries like India (0.41), Korea (0.40) and Singapore (0.59) had relatively higher rate of PD-associated peritonitis. Two tuberculosis peritonitis patients died. The rate of catheter removal was approximately 20%. Gram-negative bacteria and MTB have a higher risk of catheter loss. About one-fifth used rainwater to clean their CAPD exit site. Out of this group, 33% did not boil the rainwater prior to usage.
CONCLUSION: Patient's characteristics and microbial susceptibility vary in different places of practice. The high rates of culture-negative peritonitis and high mortality risks associated with TB peritonitis warrant special attention. In patients with refractory peritonitis, early catheter removal is warranted in order to reduce mortality and minimize damage to peritoneal membrane.
METHODOLOGY/PRINCIPAL FINDINGS: Aeromonas hydrophila or Aeromonas sp were genetically re-identified using a combination of previously published methods targeting GCAT, 16S rDNA and rpoD genes. Characterization based on the genus specific GCAT-PCR showed that 94 (96%) of the 98 strains belonged to the genus Aeromonas. Considering the patterns obtained for the 94 isolates with the 16S rDNA-RFLP identification method, 3 clusters were recognised, i.e. A. caviae (61%), A. hydrophila (17%) and an unknown group (22%) with atypical RFLP restriction patterns. However, the phylogenetic tree constructed with the obtained rpoD sequences showed that 47 strains (50%) clustered with the sequence of the type strain of A. aquariorum, 18 (19%) with A. caviae, 16 (17%) with A. hydrophila, 12 (13%) with A. veronii and one strain (1%) with the type strain of A. trota. PCR investigation revealed the presence of 10 virulence genes in the 94 isolates as: lip (91%), exu (87%), ela (86%), alt (79%), ser (77%), fla (74%), aer (72%), act (43%), aexT (24%) and ast (23%).
CONCLUSIONS/SIGNIFICANCE: This study emphasizes the importance of using more than one method for the correct identification of Aeromonas strains. The sequences of the rpoD gene enabled the unambiguous identication of the 94 Aeromonas isolates in accordance with results of other recent studies. Aeromonas aquariorum showed to be the most prevalent species (50%) containing an important subset of virulence genes lip/alt/ser/fla/aer. Different combinations of the virulence genes present in the isolates indicate their probable role in the pathogenesis of Aeromonas infections.
METHODS: A total of 210 Aeromonas clinical isolates were investigated: 116 from Singapore General Hospital and 94 archived clinical isolates from University of Malaya Medical Center, Malaysia. The isolates were genetically identified based on the gcat gene screening and the partial sequences of the rpoD housekeeping gene. Genetic relatedness, distribution of 15 virulence genes and 4 beta-lactamase resistance genes, and susceptibility patterns to 11 antimicrobial agents were compared.
RESULTS: Of the 210 Aeromonas isolates, A. dhakensis-94 (45%) was the dominant species in Singapore and Malaysia. Species composition was similar and enterobacterial repetitive intergenic consensus-PCR did not show genetic relatedness between strains from the two countries. Of the 15 virulence genes, A. dhakensis and A. hydrophila harbored the most compared with other species. Different combinations of 9 virulence genes (exu, fla, lip, eno, alt, dam, hlyA, aexU, and ascV) were present in A. dhakensis, A. hydrophila, and A. veronii from both the countries. Distribution of virulence genes was species and anatomic site related. Majority (>80%) of the strains were susceptible to all antimicrobial agents tested, except amoxicillin and cephalothin. A. dhakensis strains from Malaysia significantly harbored the cphA gene compared with A. dhakensis from Singapore. Multidrug resistance was mostly detected in strains from peritoneal fluids of dialysis patients.
CONCLUSION: This study revealed A. dhakensis as the dominant species isolated in both geographic regions, and that it carried a high number of virulence genes. It also highlights the geographic-related differences of virulence gene distribution and antimicrobial resistance profiles of clinical Aeromonas strains from Singapore and Malaysia.
CASE REPORT: A 54-year-old male patient was hospitalized after a trip to Malaysia with strong greenish watery diarrhea and chills. On physical examination we saw a dehydrated patient in severely reduced general condition. The stool frequency was 30/d. The laboratory examinations only showed elevated parameters of inflammation. Plesiomonas shigelloides was cultivated in the stool cultures. With appropriate substitution of fluid and electrolytes, and antidiarrheal therapy the patient resumed a normal diet without any complications. Three days later his bowel movements were normal and his general condition was greatly improved. We withheld antibiotic therapy because of the noncomplicated course of illness.
CONCLUSION: In Germany infections with Plesiomonas shigelloides are rare, an increase is observed because of increasing tourism to tropical regions. The course of infection is sometimes asymptomatic, but usually patients develop an acute gastroenteritis. Especially immunocompromised patients can show serious courses of infection. Plesiomonas shigelloides should be included in the differential diagnosis of acute gastroenteritis after journeys to tropical regions. Some of our patients, however, denied traveling to tropical regions. They also denied consuming seafood, which indicates a risk of infection in Germany. Still an infection with Plesiomonas shigelloides seems to be rare in northern European countries.