Molecular identification of potentially pathogenic free-living amoebae in environmental samples from urban areas of Kerman, Southeastern Iran

TL;DR

This study identifies potentially harmful amoebae in urban water and soil samples in Kerman, Iran, highlighting risks to public health.

Contribution

The study reports the molecular identification of pathogenic free-living amoebae in urban environmental samples in southeastern Iran.

Findings

Acanthamoeba T4, T3, and T6 genotypes were detected in fountain water samples.

Two Naegleria species, N. canariensis and N. australiensis, were identified in fountain water.

Acanthamoeba lenticulata (T5) and Vermamoeba vermiformis were found in soil samples.

Abstract

Free-living amoebae (FLA) are widely distributed protozoans in various habitats. Some genera of these amoebae have the potential to be pathogenic to humans. The aim of this study was to identify the distribution of different FLA species in various environmental sources in Kerman, southeastern Iran. A total of 141 samples, including city fountains, tap water, and soil samples, were collected from various regions of the city. After filtration and cultivation on non-nutrient agar, molecular analysis was performed using PCR-sequencing with genus specific primers for Acanthamoeba, Balamuthia, Vahlkampfidae, and Hartmannella. PCR- sequencing fountain water samples revealed the presence of Acanthamoeba, Hartmannella and Naegleria species. Among the sequences obtained from Acanthamoeba isolates, 72.7 %, 18.2 %, and 9.1 % belonged to the genotype T4, T3, and T6, respectively. Two Naegleria species were identified as Naegleria canariensis and N. australiensis. Molecular analysis of tap water samples showed the presence of Acanthamoeba T6 genotype and Hartmannella (Vermamoeba) vermiformis. Sequencing of soil samples revealed the presence of Acanthamoeba lenticulata (T5) and Vermamoeba vermiformis species. The presence of potentially pathogenic FLA in urban environments in Iran presents potential hazards of infection for the people and appropriate measures needed to minimize the risks to human health including disinfection of water systems using chlorine dioxide, molecular monitoring, the implementation of educational measures for the public and health professionals.

Figures