The purpose of this study was to determine the effect of bacteriophage P100 on strains of Listeria monocytogenes in artificially inoculated soft cheeses. A mix of L. monocytogenes 1/2a and Scott A was inoculated in Minas Frescal and Coalho cheeses (approximately 105 cfu/g) with the bacteriophage added thereafter (8.3 × 107 PFU/g). Samples were analyzed immediately, and then stored at 10 °C for seven days. At time zero, 30 min post-infection, the bacteriophage P100 reduced L. monocytogenes counts by 2.3 log units in Minas Frescal cheese and by 2.1 log units in Coalho cheese, compared to controls without bacteriophage. However, in samples stored under refrigeration for seven days, the bacteriophage P100 was only weakly antilisterial, with the lowest decimal reduction (DR) for the cheeses: 1.0 log unit for Minas Frescal and 0.8 log units for Coalho cheese. The treatment produced a statistically significant decrease in the counts of viable cells (p < 0.05) and in all assays performed, we observed an increase of approximately one log cycle in the number of viable cells of L. monocytogenes in the samples under refrigeration for seven days. Moreover, a smaller effect of phages was observed. These results, along with other published data, indicate that the effectiveness of the phage treatment depends on the initial concentration of L. monocytogenes, and that a high concentration of phages per unit area is required to ensure sustained inactivation of target pathogens on food surfaces.

Background Coinfection with human T-cell lymphotrophic virus type 1 (HTLV-1) is associated with shorter survival for adults and children infected with human immunodeficiency virus (HIV), although the reasons remain a matter of debate. We evaluated the factors associated with survival time in a large cohort of HIV/HTLV-1–coinfected and HIV-monoinfected individuals on combination antiretroviral therapy (cART). Methods In a nested, retrospective case-control study (1:1), we reviewed medical records of people with HIV infection on cART in a referral AIDS center in Salvador, Brazil. We matched 149 patients coinfected with HTLV-1 (cases) by age at HIV diagnosis and sex, to an equal number of HTLV-uninfected persons (controls). Death rates, survival time, baseline and current CD4 cell count, last HIV-1 RNA plasma viral load (pVL), and causes of death were compared between groups. Results The overall mortality rate was 2.1 person-years (76 deaths, 53 among coinfected patients). Survival time for cases (16.7 ± 0.7 years) was significantly shorter than for controls (18.1 ± 0.4 years; P = .001). Among patients with pVL &gt;50 copies/mL, coinfected patients had a shorter survival time (8.4 ± 0.8 years) than monoinfected ones (12.9 ± 1.4 years; P = .02), regardless of pVL magnitude. However, survival time did not differ for HIV-monoinfected (19.0 ± 0.4 years) or coinfected patients (20.2 ± 0.6 years) presenting with pVL &lt;50 copies/mL (P = .5). Deceased coinfected patients had higher initial CD4 count (417 ± 219 cells) than monoinfected ones with the same outcome (177 ± 160 cells; P = .004), while survivors had similar CD4 cell count at baseline, regardless of HTLV status. Conclusions Successful cART is able to normalize survival for coinfected patients and should be introduced for all coinfected patients, regardless of CD4 cell count. HIV/human T-cell lymphotrophic virus type 1 coinfection is believed to decrease survival of coinfected patients. In this case-control study, we demonstrate that successful combination antiretroviral therapy (last HIV viral load &lt;50 copies/mL) is able to improve survival of coinfected patients to levels observed for those monoinfected.

The purpose of this study was to determine the effect of sodium lactate and sodium propionate, both in combination with sodium acetate, on strains of Listeria monocytogenes in artificially inoculated soft cheeses. Minas Frescal and Coalho cheeses, inoculated with a mix of L. monocytogenes 1 ⁄ 2a and Scott A, underwent two treatments: 2% (w ⁄ v) sodium lactate in combination with 0.25% (w ⁄ v) sodium acetate and 2% (w ⁄ v) sodium propionate in combination with 0.25% (w ⁄ v) sodium acetate. The samples were analysed immediately and after 7 days at 10°C. The growth of the pathogen was inhibited in cheeses containing the salts of organic acids, and the effects of treatment were statistically significant (P < 0.05). However, there was no difference between the types of treatment applied. Our data demonstrate that the effectiveness of the salts of organic acids depended on the initial concentration of L. monocytogenes and that a higher concentration of the salts is necessary to ensure sustained inactivation of target pathogens because they are weakly antilisterial when the soft cheeses are stored at 10°C.