Legionella pneumophila (L. pneumophila) is one of the main pathogens, causing pneumonia and respiratory tract infections, especially in patients with ventilator-associated pneumonia (VAP). This study aimed to approve the hypothesis that the serogroup distribution of L. pneumophila isolates from patients is correlated with Legionella strains in the environment. A total of 280 bronchoalveolar lavage (BAL) samples from VAP patients admitted to the intensive care unit (ICU) as well as 116 water samples from different sources in four hospitals in Tehran, Iran, were evaluated for the presence of L. pneumophila infection by culture, nested polymerase chain reaction (PCR), real-time PCR, and sequencing for genetic diversity. The molecular and culture methods found 24 (8.6%) and 5 (1.8%) samples to be positive for L. pneumophila in VAP patients, while they found 23 (19.8%) and 8 (6.9%) positive samples in water resources, respectively. The sequencing results indicated that all positive clinical samples and 14 (60.8%) environmental samples were belonged to L. pneumophila serogroup 1. Smoking, age, length of ICU stay, and duration of ventilator use had strong relationship with L. pneumophila infectivity. In conclusion, this is the first report from Iran to determine minor differences in the serogroup distribution of environmental and clinical strains. However, further studies are needed to confirm this relationship in different regions of Iran.Keywords Legionella pneumophila • Ventilator-associated pneumonia • Serogroup 1 • Water resources Abbreviations L. pneumophila Legionella pneumophila VAP Ventilator-associated pneumonia BAL Bronchoalveolar lavage ICU Intensive care unit PCR Polymerase chain reaction BCYE Buffered charcoal yeast extract DST Drug susceptibility test Mip MAcrophage infectivity potentiator DFA Direct fluorescent antibody

Background: Ventilator-associated pneumonia (VAP) is a type of hospital acquired pneumonia with the mortality rate between 27% and 76% that develops more than 48-72 h after endotracheal intubation. Possible causes leading to this infection can be Mycoplasma pneumoniae. The objective of this study was to determine the presence of Mycoplasma pneumoniae in bronchoalveolar samples of patients with VAP who admitted in the intensive care unit (ICU). Materials and methods:In this cross-sectional study, 103 bronchoalveolar lavage samples were collected from VAP patients who admitted to ICU in Loghman, Erfan Niyayesh and Erfan Hospitals. Then, samples were investigated for presence of Mycoplasma pneumoniae using nested-PCR method with 16S rRNA gene. Results: 4 (3.9%) patients were positive for Mycoplasma pneumoniae. There was a significant relationship between the positive infectious agents with clinical signs (P=0.017) and the duration of using ventilator (P=0.043). Conclusion:The results of this study, as a first study in Iran, showed that Mycoplasma pneumoniae can be considered as true pathogens of the respiratory tract in patients with VAP and should be given more attention. To confirm the results of this study, further research is needed to reveal the association of this bacterium with VAP.

: A current biosafety and biosecurity crisis, SARS-CoV-2/COVID-19, threatens public health, making it crucial to assess and follow optimal laboratory conditions to prevent any contamination and spread of the lethal virus. Much medical staff have been lost to the COVID-19 pandemic. The dimensions of laboratory biosafety were examined in this study to reduce risks associated with COVID-19 treatment. In addition, this research primarily focuses on assessing laboratory biosafety regarding emerging coronaviruses. This research will determine which aspects need to be addressed to address the risks and implement them in the correct order and at the right time to be as educational as possible.