One of the biggest challenges in phage therapy is selecting the ‘right’ phage. What constitutes a ‘good’ phage is unclear, but regulators are converging on exclusion criteria for ‘bad’ phages. Here, we examine three commonly applied criteria: the lack of virulence/antibiotic resistance, the inability to transduce, and being strictly lytic (virulent). We assess the risk posed, the tools for determining the criteria, and the potential impact of the criteria.
We describe the first use of phage therapy in Canada for the treatment of a life-threatening periprosthetic joint infection (PJI), with successful outcome. PJI is a devastating complication of joint replacement surgery, with high morbidity and mortality. Our patient presented with early sepsis from a chronic recalcitrant multidrug-resistant (MDR) Staphylococcus epidermidis hip PJI which had repeatedly failed standard therapy. She had previously undergone 10 operations of the right hip, and only three weeks after completing a prolonged course of daptomycin following her most recent hip revision, she developed a draining sinus tract. Given the high burden of disease, inability to achieve surgical source control, and lack of antibiotic treatment options for long-term suppressive therapy, bacteriophage (phage) therapy was pursued. The patient underwent irrigation and debridement with complex flap reconstruction: intraoperative tissue cultures again yielded MDR S. epidermidis. We developed a novel phage therapy protocol for this patient, with twice daily, intra-articular and intravenous (7 × 109 PFU/dose) phage delivery over a planned 14-day course. Complete healing of the wound with cessation of drainage occurred within one month after treatment. A marked improvement in right hip pain and mobility occurred within three months after treatment. Twelve months following phage treatment, there is normalization of serum inflammatory markers with diminished pain, increased mobility, and no recurrent surgery. Our patient continues to improve and is currently living independently at home, with sustained clinical control of infection.
Mouse models have delivered variable recapitulation of Kyasanur Forest disease (KFD) pathology and consistently demonstrated neurological involvement which may be a limited feature of human disease. With the purpose of more accurately modelling human disease progression we infected several small-mammalian models: guinea pigs, hamsters and ferrets with a titered infectious dose of Kyasanur Forest disease virus (KFDV). Clinical indicators of disease severity were observed for seventeen days, on day eighteen a visual post-mortem analysis of visceral organs was conducted. Viral load in selected tissues was measured to infer disease signs and the establishment of viral replication. Daily monitoring did not reveal any observable signs of illness; weight loss was minimal across species and gross pathology did not indicate severe viral infection. Tissue specific tropism and establishment of viral infection was monitored by quantitative real-time polymerase chain reaction (qRT-PCR). No viral replication was detected in ferrets (n = 0/3), but was present in the spleen of guinea pigs (n = 3/3) and the brain of hamsters (n = 3/3). Low levels of viral RNA were detected in multiple hamster tissues (kidney, liver, lung and spleen) suggesting the possibility of viral tropism and possible adaptation to the host. No serological tests were performed.
Rising SARS-CoV-2 cases, testing delays, and the risk of pre-symptomatic and asymptomatic transmission provided the impetus for an in-house rapid testing program. Employees and their household contacts were encouraged to self-collect saliva samples that were pooled for routine testing using an established colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. In brief, individual or a maximum of four saliva samples were pooled and heat-inactivated to render microorganisms, especially SARS-CoV-2, non-infectious prior to being added to RT-LAMP assay tubes containing either the human sample control gene, RNase P, or a region of the SARS-CoV-2 gene, ORF1ab. During the second wave of SARS-CoV-2 infections in November 2020, two samples from an employee and a member of their household tested positive via RT-LAMP within two days of each other. A delayed clinical qRT-PCR test confirmation of both individuals 5 days later underscored the power of routine rapid testing with within-the-hour turnaround times. Workplace rapid testing programs using RT-LAMP are flexible in their design, have a reduced cost compared to qRT-PCR, may involve non-invasive self-saliva collection for increased safety for the testing personnel, and can be performed with minimal training.
We describe the first use of phage therapy in Canada for the treatment of a life-threatening periprosthetic joint infection (PJI), with successful outcome. PJI is a devastating complication of joint replacement surgery, with high morbidity and mortality. Our patient presented with early sepsis from a chronic recalcitrant multidrug-resistant Staphylococcus epidermidis hip PJI which had repeatedly failed standard therapy. She had previously undergone 10 operations of the right hip, and only three weeks after completing a prolonged course of daptomycin following her most recent hip revision, she developed a draining sinus tract. Given the high burden of disease, inability to achieve surgical source control, and lack of antibiotic treatment options for long-term suppressive therapy, bacteriophage (phage) therapy was pursued. The patient underwent irrigation and debridement with complex flap reconstruction: intraoperative tissue cultures again yielded MDR S. epidermidis . We developed a novel phage protocol for this patient, with twice daily, intra-articular and intravenous (7 × 10 9 PFU/dose) phage delivery over a planned 14-day course. Complete healing of the wound with cessation of drainage occurred within one month after treatment. A marked improvement in right hip pain and mobility occurred within three months after treatment. Twelve months following phage treatment, there is normalization of serum inflammatory markers with diminished pain, increased mobility, and no recurrent surgery. Our patient continues to improve and is currently living independently at home, with sustained clinical control of infection.
Rising SARS-CoV-2 cases, testing delays and the risk of pre-symptomatic and asymptomatic transmission provided the impetus for an in-house rapid testing program. Employees and their household contacts were encouraged to self-collect saliva samples which were pooled for routine testing using an established colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. In brief, individual or a maximum of four saliva samples were pooled, heat-inactivated to render microorganisms, especially SARS-CoV-2, non-infectious prior to being added to RT-LAMP assay tubes containing either human sample control gene, RNase P or a region of the SARS-CoV-2 gene, ORF1ab. During the second wave of SARS-CoV-2 infections in November 2020, two samples from an employee and a member of their household tested positive via RT-LAMP within two days of each other. A delayed clinical qRT-PCR test confirmation of both individuals 5 days later underscores the power of routine rapid testing with with-in-the-hour turnaround times. Workplace rapid testing programs using RT-LAMP are flexible in their design, have a reduced cost compared to qRT-PCR, may involve non-invasive self-saliva collection for increased safety for the testing personnel, and can be performed with minimal training.