ABSTRACT
This study aimed to investigate the knowledge, attitudes, and practices regarding brucellosis among parents in the Aseer region of southwestern Saudi Arabia in order to estimate the population sectors that are at high risk for accidental exposure to brucellosis. This was a cross-sectional survey conducted in 2018, including 311 participants representing various genders, ages, and levels of education. Bivariate analysis showed a significant association of good awareness of the disease with the male gender and higher education levels. Of the 311 participants, 90.0% had good knowledge, whereas 10.0% showed inadequate knowledge about brucellosis. Practices and attitudes regarding brucellosis were satisfactory as participants did not eat meat from their own animals (52.7%), did not practice slaughtering (71.4%), did not participate in the birth of animals (91.3%), were not exposed to abortion in animals (93.2%), and practiced burial of aborted animal fetuses (59.2%). The practice regarding brucellosis was unsatisfactory as 66.6% never wore gloves when dealing with animals. The study concluded that the majority of parents showed fair and positive knowledge, attitudes, and practices regarding brucellosis and found that gender and education were determinants of satisfactory awareness.
ABSTRACT
BACKGROUND: A novel coronavirus was identified at the end of 2019 in Wuhan City, China. Later, it was named as coronavirus disease 2019 (COVID-19) and declared a pandemic in March 2020. Saudi and global health agencies have provided various COVID-19 knowledge tools and facts to the general public. Therefore, this study aims to assess COVID-19 knowledge among the general public in Saudi Arabia at the early stages of the pandemic. PARTICIPANTS AND METHODS: A cross-sectional study was conducted in March 2020 in Saudi Arabia. The study included 1006 participants who responded to a random online COVID-19 public knowledge questionnaire that included five sections: demographic characteristics, general knowledge, prevention practices, home quarantine measures, and knowledge of governmental restrictions. Three levels of knowledge were established: excellent, intermediate, and poor. Differences in the percentages of participants with different knowledge levels by the demographic variables were analyzed using the chi-square test. RESULTS: Regarding overall general knowledge of COVID-19, 75%, 24%, and 1% of the participants had excellent, intermediate, and poor knowledge levels, respectively. Knowledge levels were significantly different by nationality and age (P=0.027 and 0.008, respectively). Most participants (98.4%) reported excellent knowledge of prevention practices, with no statistically significant differences among groups (P>0.005). Older age groups reported higher knowledge of home quarantine measures (86.6% and 86.4% of the 51-60 and older than 60 age groups, respectively, P=0.001). CONCLUSION AND RECOMMENDATIONS: High levels of knowledge about the virus, including prevention practices, are essential. The provision of COVID-19 facts and knowledge tools should be focused on younger generations to enhance compliance with the governmental restrictions required to stop the spread of COVID-19.
ABSTRACT
Lactococcus lactis is the most widely exploited microorganism in global dairy fermentations. Lactococcal strains are described as typically harboring a number of prophages in their chromosomes. The presence of such prophages may provide both advantages and disadvantages to the carrying host. Here, we describe the deliberate generation of three distinct lysogens of the model lactococcal strain 3107 and the impact of additional prophage carriage on phage-resistance and anti-microbial susceptibility. Lysogen-specific responses were observed, highlighting the unique relationship and impact of each lysogenic phage on its host. Both homologous and heterologous phage-resistance profiles were observed, highlighting the presence of possible prophage-encoded phage-resistance factors. Superinfection exclusion was among the most notable causes of heterologous phage-resistance profiles with resistance observed against members of the Skunavirus, P335, P087, and 949 lactococcal phage groups. Through these analyses, it is now possible to identify phages that may pursue similar DNA injection pathways. The generated lysogenic strains exhibited increased sensitivity to the antimicrobial compounds, nisin and lysozyme, relative to the parent strain, although it is noteworthy that the degree of sensitivity was specific to the individual (pro)phages. Overall, the findings highlight the unique impact of each prophage on a given strain and the requirement for strain-level analysis when considering the implications of lysogeny.
ABSTRACT
The tail tape measure protein (TMP) of tailed bacteriophages (also called phages) dictates the tail length and facilitates DNA transit to the cell cytoplasm during infection. Here, a thorough mutational analysis of the TMP from lactococcal phage TP901-1 (TMPTP901-1) was undertaken. We generated 56 mutants aimed at defining TMPTP901-1 domains that are essential for tail assembly and successful infection. Through analysis of the derived mutants, we determined that TP901-1 infectivity requires the N-terminal 154 aa residues, the C-terminal 60 residues and the first predicted hydrophobic region of TMPTP901-1 as a minimum. Furthermore, the role of TMPTP901-1 in tail length determination was visualized by electron microscopic imaging of TMP-deletion mutants. The inverse linear correlation between the extent of TMPTP901-1-encoding gene deletions and tail length of the corresponding virion provides an estimate of TMPTP901-1 regions interacting with the connector or involved in initiator complex formation. This study represents the most thorough characterisation of a TMP from a Gram-positive host-infecting phage and provides essential advances to understanding its role in virion assembly, morphology and infection.
