Mycobacterium alvei sp. nov

A new species of rapidly growing, nonphotochromogenic mycobacteria, Mycobacterium alvei, is described. The inclusion of this organism in the genus Mycobacterium is based on its acid fastness, its mycolate pattern, and its G + C content. A study of six strains showed that they form a homogeneous group with an internal phenotypic similarity value of 97 +/- 2.22%. DNA relatedness studies showed that the six M. alvei strains which we studied form a single DNA hybridization group which is less than 49% related to 14 other species of the genus Mycobacterium; the deltaTm values determined for the strains which exhibited higher levels of DNA homology were all greater than 7.9 degrees C. A lipid analysis showed that tuberculostearic acid was present. Docosanoic and tetracosanoic acid methyl esters were detected as mycolic acid cleavage products. All six isolates which we tested contained alpha-mycolic acids and relatively large amounts of a new kind of mycolic acid containing a methoxy group of omega-1 position, a characteristic that has not been described previously in mycobacteria. Strain CR-21 is the type strain; a culture of this strain has been deposited in the Collection Nationale de Cultures de Microorganismes de l'Institut Pasteur, Paris, France, as strain CIP 103464.

Human immunodeficiency virus (HIV) infection in parenteral drug users: evolution of the epidemic over 10 years. Valencian Epidemiology and Prevention of HIV Disease Study Group

BACKGROUND

Evaluation of acquired immunodeficiency syndrome (AIDS) prevention strategies requires an on-going follow up of the frequency of human immunodeficiency virus (HIV-1) infection. The aim of this study was to examine the trends in prevalence and incidence of HIV-1 infection among injecting drug users (IDU) during the period 1987-1996.

METHODS

Transversal and cohort studies were designed which included a consecutive sample of 7132 IDU who attended three AIDS Prevention and Information Centres in the Region of Valencia (Spain) and voluntarily asked to be tested for HIV antibodies. The prevalence was estimated for each year based on the serological status of HIV-1 when the patient first visited the centre. The annual incidence rates were calculated based on the seronegative patients in which a new determination of HIV-1 was done. In order to control the possible effects on the estimations of age, sex and duration of addiction of the people studied, Poisson and logistic regression models were adjusted.

RESULTS

Prevalence and incidence rates of HIV-1 infection showed parallel trends over time. The overall prevalence found was 43.6% (95% confidence intervals [CI]: 42.4-44.7%). Of the 4023 seronegative individuals, 1746 were followed up over the whole of the study period. The incidence rate observed was 6.85 x 100 persons/year (95% CI : 6.04-7.66). The prevalence figures show a decrease, which is most marked from 1990 onwards and then they tend to stabilize over the past few years. The incidence rates increase slightly up to 1991 (9.8 x 100 persons/year), and then begin to decrease.

CONCLUSION

Trends of prevalence of HIV-1 infection approximate trends of subjacent incidence rate. Despite decrease in HIV-1 infection frequency observed over 10 years, both the prevalence and incidence figures continue to be high in absolute terms. It is necessary to intensify and adapt preventive measures to each subgroup at risk of infection and in the case of heterosexual transmission ensure that the failure observed in the case of IDU is not repeated.

Distribution of a novel mycolic acid in species of the genus Mycobacterium

We found that Mycobacterium porcinum ATCC 33776T (T = type strain) contains a new kind of mycolic acid with a methoxy group at the omega-1 position. This mycolic acid was identified by comparing it with the previously described methoxymycolic acids. The patterns of mycolic acid methyl esters from 418 strains belonging to 44 species of mycobacteria were studied by using thin-layer chromatography. In addition to M. procinum ATCC 33776T, representative strains of M. porcinum, Mycobacterium fortuitum, "Mycobacterium peregrinum," Mycobacterium senegalense, and a recently isolated Mycobacterium sp. contained appreciable amounts of the newly described mycolic acid.

Characterization of the heterologous invertase produced by Schizosaccharomyces pombe from the SUC2 gene of Saccharomyces cerevisiae

In order to gain information on the ability of Schizosaccharomyces pombe to process heterologous glycoproteins, the heterologous invertase, obtained from the expression in Schiz. pombe of the SUC2 gene of Saccharomyces cerevisiae, was characterized. In Schiz. pombe the heterologous invertase is secreted into the cell wall and seems to be firmly bound to this structure. After the isolation of the heterologous invertase the study of its enzymatic characteristics revealed that it is more similar to the Sacch. cerevisiae external invertase than to the Schiz. pombe invertase. However, it is glycosylated like the Schiz. pombe invertase since it reacts with the lectin from Bandeiraea simplicifolia seeds conjugated to fluorescein isothiocyanate, which indicates the presence of terminal galactose residues in the enzyme. Moreover, the presence of galactose in the heterologous invertase has been confirmed after analysis of the sugars present in its carbohydrate moiety by gas liquid chromatography.

Lineage-restricted chromosome translocation in a benign fibrous tumor of the breast

We describe a clonal chromosome rearrangement, t(4;14)(q24-25;q24.3), in a benign fibrous tumor of the breast. This is the first reported cytogenetic analysis of a fibrous tumor of the breast and the first evidence for clonality in these lesions. A combined immunohistochemical/cytogenetic study demonstrated that cells with the clonal translocation were mesenchymal. Epithelial cells, in contrast, had normal chromosomes.

Gas chromatographic whole-cell fatty acid analysis as an aid for the identification of mixed mycobacterial cultures

Gas chromatographic analysis of whole-cell fatty acids, secondary alcohols and mycolic acid cleavage products could be a useful technique in checking mixed mycobacterial cultures. The mixed cultures were confirmed when species-specific compounds of different mycobacterial species were detected in the same chromatogram.

Schizosaccharomyces pombe fragile mutants as a host for heterologous protein production

In order to gain information about the potential interest of the Schizosaccharomyces pombe srb 1 fragile mutants as a host for heterologous protein production, the extracellular secretion of homologous and heterologous invertases was investigated. Under catabolic derepression the fragile srb 1 mutants released into the extracellular medium 5-6-fold more invertase than the parental strain. When transformed with the SUC2 gene, which codes for Saccharomyces cerevisiae invertase, the srb 1-3 fragile mutant, grown under catabolic repression, released into the medium 3-fold more invertase than the wild-type transformant, even though the majority of the enzyme remained associated with the cell wall. Electrophoretic analysis revealed the presence in the fragile strains of some invertase forms with molecular weights smaller than their parallel wild-type strains, suggesting that the srb 1 mutants may underglycosylate not only their homologous but also the heterologous proteins.

Isolation and characterization of Schizosaccharomyces pombe fragile mutants

Three Schizosaccharomyces pombe fragile mutants requiring the presence of an osmotic stabilizer to grow, that lyse when transferred into hypotonic solutions and that secrete to the extracellular medium more protein than the parental strain were isolated. In the three mutants, the fragile phenotype segregated in a Mendelian fashion, indicating a single chromosomal gene mutation, and behaved as a recessive character. By complementation analysis, the three fragile mutants fell in a single complementation group, defining the same gene (SRB1). Mutations of this gene are responsible for alterations in the cells such as fragile character, increase in the cell wall porosity, changes in the cell morphology and floc-forming ability. The study of the three srb1 alleles indicated that the degree of these alterations is proportional to a significant decrease in the galactomannan fraction of the mutants cell wall. The data presented in this report suggest that the product of the SRB1 gene is critical for the maintenance of the integrity and structure of Sz. pombe cell wall.

[Primary and initial bacterial resistances in tuberculosis patients at a general hospital, 1983-1987]

From july 1982 to december 1987 we prospectively evaluated the primary resistance (PR) of 248 strains of M. tuberculosis isolated from patients with several clinical forms of tuberculosis. The results were compared with those of a similar study carried out between 1978-1982. PR persisted relatively stable with time, although it showed a trend towards reduction. Isoniazide resistance (4.8%) still has a leading epidemiological interest. The 89% of strains showed isolated resistance to a single drug. Only two strains had associated resistance to INH and SM. Strains with PR to RIF, ETB or PZA were not detected. Of the 248 evaluated strains, 32 were isolated from intravenous drug abusers with AIDS. Only one of these strains had a low level (0.2 mg/l) PR to INH. At last two of these drug abusers developed acquired resistance to INH and ETB-RIF, respectively. Considering the difficulty to control chemotherapy in this group of patients, our finding has a considerable epidemiological interest.

[Changes in chest wall and lung compliance during laparoscopic cholecystectomy]

INTRODUCTION

The performance of laparoscopic cholecystectomy leads to hemodynamic and gasometric changes as well as to mechanical changes in respiration. The last phenomenon has been less studied in spite of its impact on the patient during surgery.

OBJECTIVE

To study changes in chest wall compliance (Ccw) and lung compliance (CL) during laparoscopic cholecystectomy. Material and methods. Nine patients scheduled for laparoscopic cholecystectomy were enrolled. Tidal volume, plateau pressure (Pt) and esophageal (Pes) were measured and the data were used to calculate respiratory system compliance (Crs), Ccw and CL. Measurements were taken at three moments: T1, with the patients in supine decubitus position; T2, in anti-Trendelenburg position with pneumoperitoneum; T3, after withdrawal of pneumoperitoneum with the patient in supine decubitus position.

RESULTS

Pt was seen to increase 57%, with a 100% increase in Pes when the patient was placed in anti-Trendelenburg position and pneumoperitoneum was established. Crs changed 44%, with a greater increase taking place in Ccw (52%) than in CL (32%). Baseline values for both pressure and compliance were recovered by T3.

CONCLUSIONS

Reduced respiratory compliance occurs during laparoscopic cholecystectomy mainly at the chest wall, with much less reduction taking place in the lung. Thus, intrathoracic pressure increases will be greater than transpulmonary pressure increases.

Air pollution and meteorological variables' effects on COVID-19 first and second waves in Spain

The aim of this research is to study the influence of atmospheric pollutants and meteorological variables on the incidence rate of COVID-19 and the rate of hospital admissions due to COVID-19 during the first and second waves in nine Spanish provinces. Numerous studies analyze the effect of environmental and pollution variables separately, but few that include them in the same analysis together, and even fewer that compare their effects between the first and second waves of the virus. This study was conducted in nine of 52 Spanish provinces, using generalized linear models with Poisson link between levels of PM10, NO2 and O3 (independent variables) and maximum temperature and absolute humidity and the rates of incidence and hospital admissions of COVID-19 (dependent variables), establishing a series of significant lags. Using the estimators obtained from the significant multivariate models, the relative risks associated with these variables were calculated for increases of 10 µg/m3 for pollutants, 1 °C for temperature and 1 g/m3 for humidity. The results suggest that NO2 has a greater association than the other air pollution variables and the meteorological variables. There was a greater association with O3 in the first wave and with NO2 in the second. Pollutants showed a homogeneous distribution across the country. We conclude that, compared to other air pollutants and meteorological variables, NO2 is a protagonist that may modulate the incidence and severity of COVID-19, though preventive public health measures such as masking and hand washing are still very important.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13762-022-04190-z.