The first detection of SARS-CoV-2 RNA in the wastewater of Tehran, Iran.

Following the official announcement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide pandemic spread by WHO on March 11, 2020, more than 300,000 COVID-19 cases reported in Iran resulting in approximately 17,000 deaths as of August 2, 2020. In the present survey, we investigated the presence of SARS-CoV-2 RNA in raw and treated wastewater samples in Tehran, Iran. Untreated and treated wastewater samples were gathered from four wastewater treatment plants over a month period from June to July 2020. Firstly, an adsorption-elution concentration method was tested using an avian coronavirus (infectious bronchitis virus, IBV). Then, the method was effectively employed to survey the presence of SARS-CoV-2 genome in influent and effluent wastewater samples. SARS-CoV-2 RNA was found in 8 out of 10 treated wastewater samples utilizing a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) test to detect ORF1ab and N genes. Moreover, the rate of positivity in wastewater samples increased in last sample collection that shows circulation of SARS-CoV-2 was increased among the population. In addition, the high values detected in effluent wastewater from local wastewater treatment plants have several implications in health and ecology that should be further assessed.

Prevalence and characterization of Clostridium perfringens toxinotypes among patients with antibiotic-associated diarrhea in Iran.

Clostridium perfringens has emerged as an important cause of antibiotic-associated diarrhea (AAD), particularly in the hospital environment. Here we investigated the prevalence and molecular epidemiology of C. perfringens isolated from 2280 fecal samples from Iranian diarrheal patients suspected of having AAD. Overall, AAD was diagnosed in 13.3% (303/2280) of patients and associated with advanced age (>50 years, P = 0.001). A total of 106 C. perfringens isolates were cultured from AAD (n = 68) and non-AAD (n = 38) groups, with toxinotypes A and F comprising 84% and 16% of isolates, respectively. Notably, 41.2% of type F strains were also cpb2-positive and enterotoxigenic cpe-positive strains were detected in 13.2% of the isolates from AAD patients. Genes associated with the VirR/VirS signal transduction (virR, virS) and accessory gene regulator (agrB, agrD) systems were detected in 56.6% and 67% of the isolates, respectively, and peptides of the quorum-sensing modulator, AgrD were highly conserved across all strains. The high prevalence of C. perfringens in Iranian AAD patients suggests that diagnostic laboratories in this region should consider screening for C. perfringens in cases of suspected AAD, especially if the specimen is negative for other pathogens and/or the patients are aged >50 years.