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1.
Microorganisms ; 12(8)2024 Aug 14.
Article in English | MEDLINE | ID: mdl-39203518

ABSTRACT

Vancomycin-resistant enterococci (VRE) commonly colonize the gut of individuals with hematologic malignancies or undergoing hematopoietic cell transplant (HCT) and may cause bacteremia. In 2012, we identified VRE isolates from patients and patients' rooms and showed transmission networks of highly genetically related daptomycin-resistant (DR)-VRE strains. This is a follow-up study performing whole-genome sequencing (WGS) and phylogenetic analyses on 82 clinical VRE strains isolated from stools and blood cultures of patients with leukemia and HCT between 2015 and 2019. Here, we observed transmission of highly genetically related strains between rooms on the same or on different floors, including a DR-VRE strain identified in 2012. Eleven of twenty-eight patients with DR-VRE were never exposed to daptomycin, suggesting horizontal transmission. Fifteen of the twenty-eight patients with DR-VRE died within 30 days of positive blood cultures. Amongst those, one DR-VRE strain belonging to ST1471 had the virulence gene bopD responsible for biofilm formation. Additionally, to our knowledge, this is the first report of a DR-VRE strain belonging to ST323 in the United States. In summary, our study demonstrated the emergence and persistence of VRE strains, especially DR-VRE, in our hospital. Adding WGS to routine infection control measures may timely identify potential horizontal VRE transmission including multi-drug-resistant isolates.

2.
Open Forum Infect Dis ; 10(8): ofad386, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37636519

ABSTRACT

Background: Cytomegalovirus (CMV) infection is a common opportunistic infection after allogeneic hematopoietic cell transplant (alloHCT). We explored whether a change in CMV cell-mediated immunity during the first month after transplant predicts the risk of development of CMV infection and all-cause mortality. Methods: This follow-up analysis is based on data from the REACT study, a multicenter prospective observational study of recipients of alloHCT who were CMV-seropositive. Production of interferon γ following ex vivo stimulation with CMV antigens IE1 (immediate early 1) and pp65 (phosphoprotein 65) was assessed by CMV ELISPOT assay at baseline and 2 and 4 weeks after transplant. Clinically significant CMV infection (CS-CMVi) was defined as CMV viremia and/or disease necessitating antiviral therapy. We evaluated the impact of CMV CMI changes on the risk of CS-CMVi and post transplant mortality. Results: The analysis included 226 recipients of alloHCT with CMV cell-mediated immunity data at baseline and 2 and/or 4 weeks after transplant. CS-CMVi occurred in 64 patients (28%). On Cox regression analyses, independent predictors of CS-CMVi included a negative Δ change from baseline to week 2 of pp65 spot counts (hazard ratio, 3.65 [95% CI, 1.65-8.04]; P = .001) to week 4 of IE1 spot counts (hazard ratio, 2.79 [95% CI, 1.46-5.35]; P = .002), anti-thymocyte globulin conditioning regimen, type of transplant, female sex, and corticosteroid use. Kaplan-Meir analysis showed a significant association of a negative IE1 change from baseline to week 4 and increased all-cause mortality after transplant (log rank test = 0.041). Conclusions: A decrease in CMV-specific T-cell responses during the first month after transplant may predict CS-CMVi and is associated with all-cause mortality in recipients of alloHCT.

3.
Front Microbiol ; 13: 1055427, 2022.
Article in English | MEDLINE | ID: mdl-36466675

ABSTRACT

Although some gastrointestinal diseases could be managed using various antibiotics regimen, this therapeutic approach lacks precision and damages the microbiota. Emerging literature suggests that phages may play a key role in restoring the gut microbiome balance and controlling disease progression either with exogenous phage intervention or filtered fecal transplantation or even engineered phages. In this review, we will discuss the current phage applications aiming at controlling the bacterial population and preventing infection, inflammation, and cancer progression in the context of gastrointestinal diseases.

4.
Pharmaceutics ; 14(8)2022 Jul 30.
Article in English | MEDLINE | ID: mdl-36015218

ABSTRACT

Phages are naturally occurring viruses that selectively kill bacterial species without disturbing the individual's normal flora, averting the collateral damage of antimicrobial usage. The safety and the effectiveness of phages have been mainly confirmed in the food industry as well as in animal models. In this study, we report on the successful isolation of phages specific to Vancomycin-resistant Enterococci, including Enterococcus faecium (VREfm) and Enterococcus faecalis from sewage samples, and demonstrate their efficacy and safety for VREfm infection in the greater wax moth Galleria mellonella model. No virulence-associated genes, antibiotic resistance genes or integrases were detected in the phages' genomes, rendering them safe to be used in an in vivo model. Phages may be considered as potential agents for therapy for bacterial infections secondary to multidrug-resistant organisms such as VREfm.

5.
Clin Infect Dis ; 73(12): 2306-2313, 2021 12 16.
Article in English | MEDLINE | ID: mdl-33421068

ABSTRACT

BACKGROUND: Vancomycin-resistant enterococci (VRE) are a major cause of morbidity and mortality in immunocompromised patients. Tracking the dissemination of VRE strains is crucial to understand the dynamics of emergence and spread of VRE in the hospital setting. METHODS: Whole genome sequencing (WGS) and phylogenetic analyses were performed to identify dominant VRE strains and potential transmission networks between 35 patients with VRE-positive rectal swabs and their rooms (main rooms and bathrooms) on the leukemia (LKM) and the hematopoietic cell transplant (HCT) floors. Sequence types (STs), drug resistance genes, and patients' outcomes were also determined. RESULTS: A total of 89 VRE strains grouped into 10 different STs, of which newly described STs were isolated from both floors (ST736, ST494, ST772, and ST1516). We observed highly genetically related strains transmitted between rooms, floors, and time periods in an average period of 39 days (ranging from 3 to 90 days). Of 5 VRE bacteremia events, 3 strains were lacking the pili operon fms14-17-13 (ST203) and the remaining 2 were resistant to daptomycin (DAP; ST736, ST664). Of 10 patients harboring DAP-resistant strains, only 2 were exposed to DAP within 4 months before strain recovery. CONCLUSIONS: Our comparisons of VRE strains derived from the environment and immunocompromised patients confirmed horizontal transfer of highly related genetic lineages of multidrug-resistant (particularly to DAP) VRE strains between HCT and LKM patients and their room environment. Implementing WGS can be useful in distinguishing VRE reservoirs where interventions can be targeted to prevent and control the spread of highly resistant organisms.


Subject(s)
Daptomycin , Gram-Positive Bacterial Infections , Hematopoietic Stem Cell Transplantation , Vancomycin-Resistant Enterococci , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Daptomycin/pharmacology , Daptomycin/therapeutic use , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/epidemiology , Hospitals , Humans , Microbial Sensitivity Tests , Phylogeny , Vancomycin-Resistant Enterococci/genetics
6.
Clin Infect Dis ; 71(9): 2365-2374, 2020 12 03.
Article in English | MEDLINE | ID: mdl-32076709

ABSTRACT

BACKGROUND: Cytomegalovirus (CMV) infection remains an important cause of morbidity and mortality in allogeneic hematopoietic cell transplant (allo-HCT) recipients. CMV cell-mediated immunity (CMV-CMI) as determined by a peptide-based enzyme-linked immunospot (ELISPOT) CMV assay may identify patients at risk for clinically significant CMV infection (CS-CMVi). METHODS: The CS-CMVi was defined as CMV viremia and/or disease necessitating antiviral therapy. CMV-CMI was characterized as high when the intermediate-early 1 (IE-1) antigen spot counts (SPCs) were >100 (cutoff 1) or when the IE-1 and phosphoprotein 65 antigen SPCs were both >100 SPCs per 250 000 cells (cutoff 2), and a low CMV-CMI when SPCs were below these thresholds. In this prospective multicenter study, we evaluated CMV-CMI every 2 weeks from the pretransplant period until 6 months posttransplantation in 241 allo-HCT recipients with positive CMV serostatus. The primary endpoint was CS-CMVi occurring within 2 weeks of the last measurement of CMV-CMI. RESULTS: CS-CMVi occurred in 70 allo-HCT recipients (29%). CMV-CMI was low in patients who experienced CS-CMVi (94%), whereas those who had a high CMV-CMI were less likely to have CS-CMVi (P < .0001). Patients with CS-CMVi had higher all-cause mortality (P = .007), especially those with low CMV-CMI (P = .035). On multivariable analysis, CMV-CMI, sex, race, antithymocyte globulin, and steroid use were independent predictors of CS-CMVi, and the time from transplant to engraftment was the only predictor of mortality. CONCLUSIONS: Measurement of CMV-CMI using a novel ELISPOT assay would be useful clinically to monitor allo-HCT recipients and distinguish between those at risk of developing CS-CMVi and requiring antiviral prophylaxis or therapy and those who are protected.


Subject(s)
Cytomegalovirus Infections , Hematopoietic Stem Cell Transplantation , Antiviral Agents/therapeutic use , Cytomegalovirus , Cytomegalovirus Infections/drug therapy , Cytomegalovirus Infections/epidemiology , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Immunity, Cellular , Prospective Studies
7.
J Med Virol ; 92(1): 86-95, 2020 01.
Article in English | MEDLINE | ID: mdl-31448830

ABSTRACT

Cytomegalovirus (CMV) infection remains a major complication after allogeneic hematopoietic cell transplantation (allo-HCT). We conducted a retrospective study to determine the clinical and economic burden of pre-emptive therapy (PET) for CMV infection in 100 consecutive hospitalized adult CMV positive serostatus allo-HCT recipients and compared their hospitalization cost with allo-HCT recipients hospitalized with graft vs host disease without CMV infection (control group) and across 19 US cancer centers for hospitalized patients with CMV infection between 2012 and 2015 (Vizient database). A total of 192 CMV episodes of PET for CMV infection occurred within 1 year post-HCT. PET consisted of ganciclovir (41% of episodes), foscarnet (40%), and valganciclovir (38%) with the longest average length of stay in foscarnet-treated patients (41 days). The average direct cost per patient admitted for PET was $116 976 (range: $7866-$641 841) compared with $12 496 (range: $2004-$43 069) in the control group (P < .0001). The total direct cost per encounter was significantly higher in patients treated with foscarnet and had nephrotoxicity ($284 006) compared with those who did not ($112 195). The average cost amongst the 19 US cancer centers, including our institution, was $42 327 with major disparities in cost and clinical outcomes. PET for CMV infection is associated with high economic burden in allo-HCT recipients.


Subject(s)
Antiviral Agents/therapeutic use , Chemoprevention/economics , Cost of Illness , Cytomegalovirus Infections/prevention & control , Hematopoietic Stem Cell Transplantation/adverse effects , Transplant Recipients/statistics & numerical data , Adult , Aged , Cytomegalovirus Infections/drug therapy , Female , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Retrospective Studies , Transplantation, Homologous/adverse effects , Young Adult
8.
Curr Opin Infect Dis ; 32(6): 565-574, 2019 12.
Article in English | MEDLINE | ID: mdl-31567572

ABSTRACT

PURPOSE OF REVIEW: Refractory or resistant cytomegalovirus (CMV) infections are challenging complications after hematopoietic cell transplantation (HCT). Most refractory or resistant CMV infections are associated with poor outcomes and increased mortality. Prompt recognition of resistant or refractory CMV infections, understanding the resistance pathways, and the treatment options in HCT recipients are imperative. RECENT FINDINGS: New definitions for refractory and resistant CMV infections in HCT recipients have been introduced for future clinical trials. Interestingly, refractory CMV infections are more commonly encountered in HCT recipients when compared with resistant CMV infections. CMV terminase complex mutations in UL56, UL89, and UL51 could be associated with letermovir resistance; specific mutations in UL56 are the most commonly encountered in clinical practice. Finally, brincidofovir, maribavir, letermovir, and CMV-specific cytotoxic T-cell therapy expanded our treatment options for refractory or resistant CMV infections. SUMMARY: Many advances have been made to optimize future clinical trials for management of refractory or resistant CMV infections, and to better understand new resistance mechanisms to novel drugs. New drugs or strategies with limited toxicities are needed to improve outcomes of difficult to treat CMV infections in HCT recipients.


Subject(s)
Antiviral Agents/therapeutic use , Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/etiology , Cytomegalovirus Infections/therapy , Cytomegalovirus/drug effects , Drug Resistance, Viral , Hematopoietic Stem Cell Transplantation/adverse effects , Antiviral Agents/pharmacology , Cytomegalovirus/genetics , Cytomegalovirus Infections/epidemiology , DNA, Viral , Disease Management , Humans , Incidence , Mutation , Transplant Recipients
10.
Clin Infect Dis ; 69(1): 167-178, 2019 06 18.
Article in English | MEDLINE | ID: mdl-30395179

ABSTRACT

Bacteriophages (phages) may constitute a natural, safe, and effective strategy to prevent and control multidrug-resistant organisms (MDROs), and ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens in particular. Few clinical studies have assessed the safety and efficacy of phages in patients infected with MDROs. This systematic review summarizes and critically evaluates published studies of phages in clinical practice and presents the appropriate phage selection criteria, as well as recommendations for clinicians and scientists for a successful therapy. Articles were identified through a search of the PubMed, Ovid, EMBASE, and Cochrane Library databases. Among 1102 articles and abstracts, 30 studies were selected and evaluated using selective inclusion criteria, phage criteria, and study characteristics. Most studies showed efficacy (87%) and safety (67%) of the tested phages, but few studies examined phage resistance (35%). Clinical studies and regulatory changes are needed to determine the safety and efficacy of phages and to advance their use in patients with MDRO infections.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacterial Infections/therapy , Drug Resistance, Multiple, Bacterial , Phage Therapy , Acinetobacter Infections/prevention & control , Acinetobacter Infections/therapy , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Clinical Trials as Topic , Gram-Positive Bacterial Infections/prevention & control , Gram-Positive Bacterial Infections/therapy , Humans , Klebsiella Infections/prevention & control , Klebsiella Infections/therapy , Pseudomonas Infections/prevention & control , Pseudomonas Infections/therapy , Staphylococcal Infections/prevention & control , Staphylococcal Infections/therapy
11.
J Infect Dis ; 219(6): 898-907, 2019 02 23.
Article in English | MEDLINE | ID: mdl-30295846

ABSTRACT

BACKGROUND: Cytomegalovirus (CMV) infections in hematopoietic cell transplant (HCT) recipients cause substantial morbidity and mortality. CMV cell-mediated immunity (CMV-CMI) can be determined by levels of interferon gamma (IFN-γ) production using an enzyme-linked immunospot (ELISPOT) CMV assay (T-SPOT.CMV assay). In this study, we evaluated the ability of this assay to predict the outcome of low-level CMV reactivation in HCT recipients. METHODS: We followed 55 HCT recipients with low-level CMV reactivation up to 8 weeks from enrollment. Progression to clinically significant CMV infection (CS-CMVi) was defined as a CMV load >1000 IU/mL or > 500 IU/mL in patients receiving matched related/autologous or matched unrelated transplants, respectively, and initiation of antiviral treatment. RESULTS: Progression to CS-CMVi occurred in 31 (56%) of the HCT recipients. Spot counts of CMV-specific pp65 and IE1 antigens were significantly lower in patients who had CS-CMVi than in patients who did not. On multivariate analysis, the ELISPOT CMV responses and steroids use were the only predictors of progression to CS-CMVi. CONCLUSIONS: A strong association between low CMV-CMI and progression to CS-CMVi was observed in HCT recipients. The implementation of serial monitoring of CMV-CMI may identify patients at risk of progression to CS-CMVi that require antiviral therapy.


Subject(s)
Cytomegalovirus Infections/diagnosis , Cytomegalovirus/physiology , Enzyme-Linked Immunospot Assay , Hematopoietic Stem Cell Transplantation/adverse effects , Adolescent , Adult , Aged , Antigens, Viral/immunology , Antiviral Agents/therapeutic use , Biomarkers/blood , Cohort Studies , Cytomegalovirus/immunology , Cytomegalovirus Infections/immunology , Cytomegalovirus Infections/virology , Female , Humans , Immunity, Cellular , Interferon-gamma/blood , Male , Middle Aged , Prospective Studies , Transplant Recipients , Viral Load , Virus Activation
12.
Curr Opin Infect Dis ; 31(6): 542-552, 2018 12.
Article in English | MEDLINE | ID: mdl-30320640

ABSTRACT

PURPOSE OF REVIEW: In hematopoietic cell transplant (HCT) recipients, paramyxovirus infections are major viral respiratory tract infections that, if they progress to lower respiratory tract infections, are associated with reduced survival rates in this population. There are important knowledge gaps regarding treatment decisions for HCT recipients with these infections and in the identification of risk factors that predict infection severity. Here, we review recent data on paramyxovirus infections in HCT recipients focusing on risk factors, new diagnostic and prognostic tools, and management including new drugs and vaccines under development. RECENT FINDINGS: Multiplexed molecular assays associated with immunodeficiency scoring index for respiratory syncytial virus (RSV) have improved our understanding of the epidemiology of RSV and other paramyxovirus infections and the risk factors for worse outcomes. Novel antiviral drugs, monoclonal antibodies, and vaccines are under evaluation with mixed preliminary results. SUMMARY: Advances in our knowledge of paramyxovirus infections in HCT recipients in the last two decades contributed to better strategies for management and prevention of these infections. A widespread understanding of how to stratify HCT recipients with paramyxovirus infections who would benefit most from antiviral therapy remains to be ascertained. Vaccines and new drugs under development may mitigate the burden of paramyxovirus infections.


Subject(s)
Hematopoietic Stem Cell Transplantation , Respiratory Syncytial Virus Infections , Humans , Immunocompromised Host , Transplant Recipients
13.
Food Microbiol ; 76: 304-309, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30166155

ABSTRACT

In an effort to reduce food safety risks, virulent phages are investigated as antibacterial agents for the control of foodborne pathogens. The aim of this study was to evaluate microencapsulation (ME) as a tool to concentrate and store staphylococcal bacteriophages. As a proof of concept, phage Team1 belonging to the Myoviridae family was microencapsulated in alginate gel particles of 0.5 mm (micro-beads) and 2 mm (macro-beads) of diameter. Gel contraction occurred during the hardening period in the CaCl2 solution, and the diameters of the initial alginate droplets shrunk by 16% (micro-beads) and 44% (micro-beads). As compared to the phage counts in the alginate solution, this contraction resulted in the increase of the phage titers, per g of alginate gel, by factors of 2 (micro-beads) and 6 (micro-beads). The encapsulation yield was highest in the macro-beads. Although phage Team1 was successfully frozen in beads, ME did not improve phage stability to freeze-drying. The addition of glycerol protected the microencapsulated phages during freezing but had no effect on free phage suspensions. Finally, ME improved storage stability at 4 °C but had no impact on freezing or drying over three months of storage.


Subject(s)
Drug Compounding/methods , Myoviridae , Staphylococcus Phages , Alginic Acid/chemistry , Anti-Bacterial Agents/chemistry , Drug Storage , Food Safety , Freeze Drying/methods , Hydrogen-Ion Concentration
14.
J Antimicrob Chemother ; 73(11): 3162-3169, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30113677

ABSTRACT

Objectives: Respiratory syncytial virus (RSV) infection causes morbidity and mortality in cancer patients. However, studies describing this infection in patients with haematological malignancies are scarce. We sought to evaluate the clinical impact of RSV infection on this patient population. Methods: We reviewed the records of patients with haematological malignancies and RSV infections cared for at our institution between January 2000 and March 2013. Results: Of the 181 patients, 71 (39%) had AML, ALL or myelodysplastic syndrome, 12 (7%) had CML or CLL, 4 (2%) had Hodgkin lymphoma, 35 (19%) had non-Hodgkin lymphoma and 59 (33%) had multiple myeloma. Most patients [117 (65%)] presented with an upper respiratory tract infection (URTI) and 15 (13%) had a subsequent lower respiratory tract infection (LRTI). The overall LRTI rate was 44% and the 90 day mortality rate was 15%. Multivariable regression analysis showed that having both neutropenia and lymphocytopenia (adjusted OR = 7.17, 95% CI = 1.94-26.53, P < 0.01) and not receiving ribavirin-based therapy during RSV URTI (adjusted OR = 0.03; 95% CI = 0.01-0.11, P < 0.001) were independent risk factors for LRTI. Having both neutropenia and lymphocytopenia at RSV diagnosis was also a risk factor for death at 90 days after RSV diagnosis (adjusted OR = 4.32, 95% CI = 1.24-15.0, P = 0.021). Conclusions: Patients with haematological malignancies and RSV infections, especially those with immunodeficiency, may be at risk of LRTI and death; treatment with ribavirin during RSV URTI may prevent these outcomes.


Subject(s)
Antiviral Agents/therapeutic use , Hematologic Neoplasms/complications , Leukopenia/complications , Respiratory Syncytial Virus Infections/drug therapy , Respiratory Tract Infections/drug therapy , Ribavirin/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Female , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/virology , Humans , Leukopenia/virology , Male , Middle Aged , Respiratory Syncytial Virus Infections/mortality , Respiratory Tract Infections/mortality , Respiratory Tract Infections/virology , Retrospective Studies , Risk Factors , Treatment Outcome , Young Adult
15.
BMC Infect Dis ; 17(1): 672, 2017 10 10.
Article in English | MEDLINE | ID: mdl-29017457

ABSTRACT

BACKGROUND: Environmental cleanliness is one of the contributing factors for surgical site infections in the operating rooms (ORs). To decrease environmental contamination, pulsed xenon ultraviolet (PX-UV), an easy and safe no-touch disinfection system, is employed in several hospital environments. The positive effect of this technology on environmental decontamination has been observed in patient rooms and ORs during the end-of-day cleaning but so far, no study explored its feasibility between surgical cases in the OR. METHODS: In this study, 5 high-touch surfaces in 30 ORs were sampled after manual cleaning and after PX-UV intervention mimicking between-case cleaning to avoid the disruption of the ORs' normal flow. The efficacy of a 1-min, 2-min, and 8-min cycle were tested by measuring the surfaces' contaminants by quantitative cultures using Tryptic Soy Agar contact plates. RESULTS: We showed that combining standard between-case manual cleaning of surfaces with a 2-min cycle of disinfection using a portable xenon pulsed ultraviolet light germicidal device eliminated at least 70% more bacterial load after manual cleaning. CONCLUSIONS: This study showed the proof of efficacy of a 2-min cycle of PX-UV in ORs in eliminating bacterial contaminants. This method will allow a short time for room turnover and a potential reduction of pathogen transmission to patients and possibly surgical site infections.


Subject(s)
Disinfection/methods , Operating Rooms , Bacterial Load/radiation effects , Disinfection/instrumentation , Humans , Operating Rooms/methods , Ultraviolet Rays , Xenon
16.
Int J Food Microbiol ; 217: 7-13, 2016 Jan 18.
Article in English | MEDLINE | ID: mdl-26476571

ABSTRACT

Staphylococcus aureus is one of the most prevalent pathogenic bacteria contaminating dairy products. In an effort to reduce food safety risks, virulent phages are investigated as antibacterial agents to control foodborne pathogens. The aim of this study was to compare sets of virulent phages, design phage cocktails, and use them in a cocktail to control pathogenic staphylococci in cheese. Six selected phages belonging to the three Caudovirales families (Myoviridae, Siphoviridae, Podoviridae) were strictly lytic, had a broad host range, and did not carry genes coding for virulence traits in their genomes. However, they were sensitive to pasteurization. At MOI levels of 15, 45, and 150, two anti-S. aureus phage cocktails, each containing three phages, one from each of the three phage families, eradicated a 10(6)CFU/g S. aureus population after 14 days of Cheddar cheese curd ripening at 4°C. The use of these phages did not trigger over-production of S. aureus enterotoxin C. The use of phage cocktails and their rotation may prevent the emergence of phage resistant bacterial strains.


Subject(s)
Cheese/microbiology , Myoviridae/physiology , Podoviridae/physiology , Siphoviridae/physiology , Staphylococcal Food Poisoning/prevention & control , Staphylococcus aureus/virology , Anti-Bacterial Agents , Biological Control Agents , Enterotoxins/biosynthesis , Food Microbiology/methods , Food Safety/methods , Host Specificity , Pasteurization
17.
PLoS One ; 9(7): e102600, 2014.
Article in English | MEDLINE | ID: mdl-25061757

ABSTRACT

Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the Myoviridae family. Phage Team1 was propagated on a Staphylococcus aureus strain and a non-pathogenic Staphylococcus xylosus strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 S. aureus strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on S. xylosus lysed 52 out of 57 distinct strains of S. aureus. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes.


Subject(s)
Genome, Viral , Staphylococcus Phages/genetics , Staphylococcus aureus/virology , Fermentation , Food Handling , Humans , Meat/microbiology , Staphylococcus Phages/pathogenicity , Staphylococcus aureus/genetics , Staphylococcus aureus/growth & development
18.
Genome Announc ; 2(4)2014 Jul 10.
Article in English | MEDLINE | ID: mdl-25013142

ABSTRACT

Staphylococcus xylosus is a bacterial species used in meat fermentation and a commensal microorganism found on animals. We present the first complete circular genome from this species. The genome is composed of 2,757,557 bp, with a G+C content of 32.9%, and contains 2,514 genes and 79 structural RNAs.

19.
Appl Environ Microbiol ; 79(8): 2828-32, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23396328

ABSTRACT

A new siphophage (LH1) was isolated from raw milk using a Staphylococcus aureus ST352 host. Its genome (46,048 bp, 57 open reading frames) includes the two genes encoding Panton-Valentine leukocidin (PVL), a virulence factor usually harbored by S. aureus prophages. Nine structural proteins were identified, including a tail protein generated through a +1 frameshift. A phage lytic mutant was isolated, and its analysis revealed the deletion of genes coding for the PVL and an integrase. The deletion likely occurred through recombination between direct repeats.


Subject(s)
Bacterial Toxins/genetics , Exotoxins/genetics , Leukocidins/genetics , Staphylococcus Phages/genetics , Staphylococcus aureus/virology , Animals , Base Sequence , DNA, Viral/analysis , DNA, Viral/genetics , Genes, Viral , Genetic Variation , Milk/virology , Molecular Sequence Data , Sequence Analysis, DNA , Sequence Deletion , Staphylococcus Phages/isolation & purification
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