Zoonotic Dis., Volume 2, Issue 2 (June 2022) – 3 articles

In this study, two lytic bacteriophages designated as vB_CjP and vB_CcM were isolated and evaluated for their ability to combat multidrug-resistant bacteria Campylobacter jejuni and Campylobacter coli, respectively. A morphological analysis of these phages by transmission electron microscopy revealed that the vB-CjP bacteriophage had a mean head dimension of 66.6 ± 2.1 nm and a short non-contractile tail and belongs to the Podoviridae family, whereas vB_CcM had a mean head dimension of 80 ± 3.2 nm, a contractile tail, and a length calculated to be 60 ± 2.5 nm and belongs to the Myoviridae family. The results of the host range assay showed that vB_CjP could infect 5 of 10 C. jejuni isolates, whereas vB_CcM could infect 4 of 10 C. coli isolates. Both phages were thermostable and did not lose their infectivity and ability to lyse their host following exposure to 60 °C for 10 min; furthermore, phage particles were relatively stable within a pH range of 6–8. A one-step growth curve indicated that the phages produced estimated burst sizes of 110 and 120 PFU per infected cell with latent periods of 10 and 15 min, for vB-CjP and vB-CcM, respectively. The lytic activity of these phages against planktonic Campylobacter showed that these phages were able to control the growth of Campylobacter in vitro. These results suggest that these phages have a high potential for phage applications and can reduce significantly the counts of Campylobacter spp. The lytic activity of vB-CjP and vB-CcM phages at different (MOIs) against multidrug resistance Campylobacter strains was evaluated. The bacterial growth was slightly delayed by both phages, and the highest efficiency of both phages was observed when MOI = 1 was applied. Full article

Syria has experienced armed conflict since 2011, and the provision of health care has been severely compromised due to the hostilities. At the time of writing, Northwest Syria (NWS) was outside governmental control and faced the challenges of the COVID-19 outbreak. Since the emergence of this disease, several studies have looked at the dynamics of COVID-19 transmission, predicted its progression, and determined the impact of different preventive measures. While most of these studies’ settings were in stable contexts, this study investigated the progression of the COVID-19 pandemic in Northwest Syria, a conflict-affected region, for nine months (from July 2020 to March 2021) using the Suspected-Infected-Removed (SIR) model. We adjusted the SIR model to study the impact of wearing facial masks on the outbreak dynamics and progression. Based on available data and using the basic and adjusted SIR models, we estimated the value of the basic reproduction number (R0), which provides an initial prediction of disease progression. Using the basic SIR model, the estimated R0 for the first wave of SARS-CoV-2 in Northwest Syria was 2.38. The resulting figures were overestimated in comparison with the reported numbers and data on the COVID-19 pandemic. However, the results were significantly reasonable when we adjusted the model for a preventive measure (in this case, wearing face masks). Face masks, the most available preventive measure to be applied in emergency and conflict settings, remarkably affect the outbreak dynamics and may play a key role in controlling and limiting the spread of COVID-19. The novelty of the study is provided by simulating the progress of the COVID-19 outbreak in conflict settings, as it is the first study to predict the dynamics of COVID-19 disease in NWS by adjusting for face-mask-wearing as a preventive measure to explore its impact on outbreak dynamics. Full article