Tuberculosis specific responses following therapy for TB: Impact of HIV co-infection.

Characterizing perturbations in the immune response to tuberculosis in HIV can develop insights into the pathogenesis of coinfection. HIV+ TB+ and TB monoinfected (TB+) subjects recruited from clinics in Bamako prior to initiation of TB treatment were evaluated at time-points following initiation of therapy. Flow cytometry assessed CD4+/CD8+ T cell subsets and activation markers CD38/HLA-DR. Antigen specific responses to TB proteins were assessed by intracellular cytokine detection and proliferation. HIV+ TB+ subjects had significantly higher markers of immune activation in the CD4+ and CD8+ T cells compared to TB+ subjects. HIV+ TB+ had lower numbers of TB-specific CD4+ T cells at baseline. Plasma IFNγ levels were similar between HIV+ TB+ and TB+ subjects. No differences were observed in in-vitro proliferative capacity to TB antigens between HIV+ TB+ and TB+ subjects. Subjects with HIV+ TB+ coinfection demonstrate in vivo expansion of TB-specific CD4+ T cells. Immunodeficiency associated with CD4+ T cell depletion may be less significant compared to immunosuppression associated with HIV viremia or untreated TB infection.

Facile functional analysis of insect odorant receptors expressed in the fruit fly: validation with receptors from taxonomically distant and closely related species.

With the advent of genomic sequences and next-generation sequencing technologies (RNA-Seq), multiple repertoires of olfactory proteins in various insect species are being unraveled. However, functional analyses are lagging behind due in part to the lack of simple and reliable methods for heterologous expression of odorant receptors (ORs). While the Xenopus oocyte recording system fulfills some of this lacuna, this system is devoid of other olfactory proteins, thus testing only the "naked" ORs. Recently, a moth OR was expressed in the majority of neurons in the antennae of the fruit fly using Orco-GAL4 to drive expression of the moth OR. Electroantennogram (EAG) was used to de-orphanize the moth OR, but generic application of this approach was brought to question. Here, we describe that this system works with ORs not only from taxonomically distant insect species (moth), but also closely related species (mosquito), even when the fruit fly has highly sensitive innate ORs for the odorant being tested. We demonstrate that Orco-GAL4 flies expressing the silkworm pheromone receptor, BmorOR1, showed significantly higher responses to the sex pheromone bombykol than the control lines used to drive expression. Additionally, we show that flies expressing an OR from the Southern house mosquito, CquiOR2, gave significantly stronger responses to the cognate odorants indole and 2-methylphenol than the "background noise" recorder from control lines. In summary, we validate the use of Orco-GAL4 driven UAS-OR lines along with EAG analysis as a simple alternative for de-orphanization and functional studies of insect ORs in an intact olfactory system.

On-Site Pilot-Scale Microalgae Cultivation Using Industrial Wastewater for Bioenergy Production: A Case Study towards Circular Bioeconomy.

This case study assesses the valorization of industrial wastewater streams for bioenergy generation in an industrial munition facility. On-site pilot-scale demonstrations were performed to investigate the feasibility of algal growth in the target wastewater on a larger outdoor scale. An exploratory field study followed by an optimized one were carried out using two 1000 L open raceway ponds deployed within a greenhouse at an industrial munition facility. An online system allowed for constant monitoring of operational parameters such as temperature, pH, light intensity, and dissolved oxygen within the ponds. The original algal seed evolved into an open-air resilient consortium of green microalgae and cyanobacteria that were identified and characterized successfully. Weekly measurements of the level of nutrients in pond liquors were performed along with the determination of the algal biomass to quantitatively evaluate growth yields. After harvesting algae from the ponds, the biomass was concentrated and evaluated for oil content and biochemical methane potential (BMP) to provide an estimate of the algae-based energy production. Additionally, the correlation among biomass, culturing conditions, oil content, and BMP was evaluated. The higher average areal biomass productivity achieved during the summer months was 23.9 ± 0.9 g/m2d, with a BMP of 350 scc/gVS. An oil content of 22 wt.% was observed during operation under low nitrogen loads. Furthermore, a technoeconomic analysis and life cycle assessment demonstrated the viability of the proposed wastewater valorization scenario and aided in optimizing process performance towards further scale-up.

A new spontaneous mutation in the mouse protocadherin 15 gene.

We have characterized a new allele of the protocadherin 15 gene (designatedPcdh15(av-6J)) that arose as a spontaneous, recessive mutation in the C57BL/6J inbred strain at Jackson Laboratory. Analysis revealed an inframe deletion in Pcdh15, which is predicted to result in partial deletion of cadherin domain (domain 9) in Pcdh15. Morphologic study revealed normal to moderately defective cochlear hair cell stereocilia in Pcdh15(av-6J) mutants at postnatal day 2 (P2). Stereocilia abnormalities were consistently present at P5 and P10. Degenerative changes including loss of inner and outer hair cells were seen at P20, with severe sensory cell loss in all cochlear turns occurring by P40. The hair cell phenotype observed in the 6J allele between P0 and P20 is the least severe phenotype yet observed in Pcdh15 alleles. However, young Pcdh15(av-6J) mice are unresponsive to auditory stimulation and show circling behavior indicative of vestibular dysfunction. Since these animals show severe functional deficits but have relatively mild stereocilia defects at a young age they may provide an appropriate model to test for a direct role of Pcdh15 in mechanotransduction.

Lysis-centrifugation blood culture technique. Clinical impact in Staphylococcus aureus bacteremia.

To determine the clinical impact of enhanced detection of Staphylococcus aureus by a lysis-centrifugation (LC) blood culture system, consecutive cases of S aureus bacteremia during a seven-month period were reviewed. Of 77 clinically significant cases, the LC system detected 70 cases (91%) while a conventional broth system detected 67 cases (87%). Of 60 cases detected by both systems, the LC system was positive earlier than the broth system by one or more days in 34 cases (57%) and later in none. It also detected more (12 vs four of 13) patients with persistent bacteremia who were receiving antimicrobial treatment. Forty-three patients (56%) did not receive appropriate antimicrobial therapy until cultures were reported positive. Enhanced detection of S aureus bacteremia is a clinically important advantage of the LC blood culture technique.

Optimal testing parameters for blood cultures.

The effects of volume of blood, number of consecutive cultures, and incubation time on pathogen recovery were evaluated for 37,568 blood cultures tested with the automated BACTEC 9240 instrument (Becton Dickinson Diagnostic Instrument Systems) at a tertiary care center over the period of 12 June 1996 through 12 October 1997. When the results for this study were compared with previous data published for manual broth-based blood culture systems and patient samples obtained in the 1970s and 1980s, the following were found: (1) the percentage increase in pathogen recovery per milliliter of blood is less, (2) more consecutive blood culture sets over a 24-h period are required to detect bloodstream pathogens, and (3) a shorter duration of incubation is required to diagnose bloodstream infections. Guidelines developed in the 1970s and 1980s for processing and culturing blood may require revision.

Presence of angiotensinogen messenger RNA in various cultured cell lines.

The presence of angiotensinogen messenger RNA (mRNA) was assessed in total RNA extracted from hepatoma, glioma, neuroblastoma, and glioma-neuroblastoma hybrid cell lines. Total RNA from 1 X 10(7) cells was extracted, transferred to a membrane, and hybridized with a 32P-labeled, full-length (1650-base pair) rat angiotensinogen complementary DNA (cDNA). Angiotensinogen RNA sequences could be definitively detected only in hepatoma cells. Steroids were used in an attempt to increase the angiotensinogen mRNA level. Dexamethasone (2 X 10(-6) M) or 17 beta-estradiol (1 X 10(-7) M) was added to the cultures 18 to 24 hours prior to harvest. Dexamethasone treatment of the hepatoma cells resulted in a large increase in angiotensinogen mRNA, whereas estradiol had no effect. Steroids failed to induce detectable levels of angiotensinogen mRNA in total RNA from the other cell lines. That the RNA was intact was ensured by hybridizing duplicate Northern blots to a 32P-labeled actin cDNA. Actin mRNA sequences were detected in all cell lines. Blot hybridization of poly(A)+RNA resulted in the visualization of a weak angiotensinogen mRNA signal for a glioma cell line and a glioma-neuroblastoma hybrid line. However, the ability to detect angiotensinogen mRNA in a cell may depend on the phenotype expressed, which can be governed by culture conditions.

Immunologic evaluation in the nutritional assessment of children with cancer.

Eighty-one newly diagnosed untreated pediatric cancer patients (48 hematopoeitic malignancies, 17 solid tumors, 16 benign diseases) were evaluated with immunologic and nutritional parameters. The mean absolute lymphocyte count was adequate in the three groups. Reduced T-lymphocytes were seen in the solid tumors. Mitogenic response of hematopoietic and solid tumor patients' lymphocytes was low. Correlation of immunologic, dietary, and nutritional factors showed that for patients with solid tumors there was a positive significant correlation between weight/height percent and lymphocyte reactivity to phytohemagglutinin, concanavalin A, and pokeweed mitogen (p less than .05). Iron intake showed a significant positive correlation with in vitro mitogen reactivity for the solid tumor group (p less than .05) and benign diseases (p less than 0.01). Immune derangements found among patients with hematopoietic malignancies can be due to replacement of normal bone marrow with malignant cells. In solid tumor patients mitogen reactivity appears to be a reflection of nutritional state, and dietary iron is a possible factor.

"Crack" cocaine-associated stroke.

We present three cases of "crack" cocaine-associated stroke, together with a review of cocaine-associated cerebrovascular complications. Unlike previously reported cases tentatively associating ischemic stroke with cocaine, our patients had no other potential causes for their strokes. Although the exact mechanism of cocaine-related stroke remains uncertain, both disordered neurogenic control of the cerebral circulation as well as systemic factors (ie, acute hypertension) may play a role.

The clinical microbiology laboratory. Utilization and cost-effectiveness.

Utilization of the microbiology laboratory is subject to limitations posed by the diversity of microbial agents causing infection, multiple and often poorly accessible sites of infection, contamination of specimens with indigenous flora, and failure of communication between clinician and microbiologist. Cost constraints increasingly limit the extent of microbiologic services available on-site and lead to decentralization of laboratory services and possible loss of quality control. Increased attention is being paid to process control of cultures, rapid screening and diagnostic tests as culture substitutes, and limitations on antibiotic susceptibility testing.

Infections due to group C streptococci in man.

Although a common cause of infection in animals, group C streptococci are rarely noted to be pathogenic in man. A total of 150,000 blood cultures obtained at the Mayo Clinic from 1968 to 1977 revealed group C streptococci in only eight patients. Acute bacterial endocarditis, meningitis, pheumonia, cellulitis and bacteremia due to group C streptococci are described in a host who had undergone immunosuppression (immunosuppressed host), and the relatively few cases previously reported are reviewed. Although severe, these infections may respond favorably to penicillin therapy. Endocarditis caused by group D streptococci is acute and destructive, and associated with early cardiac decompensation. The manifestations of cellulitis and pneumonia are similar to those when group A streptococci are causative organisms. Meningitis due to group C streptococci is acute and severe, and responds slowly to antimicrobial therapy. Colonization also occurs.

Selective bowel decontamination to decrease gram-negative aerobic bacterial and Candida colonization and prevent infection after orthotopic liver transplantation.

Gram-negative bacterial and fungal infections are a major cause of morbidity and mortality following liver transplantation. We therefore used selective bowel decontamination (SBD) to eliminate the endogenous source of gram-negative aerobic bacteria and Candida pathogens in an attempt to reduce the high incidence of infection related to these organisms. Thirty consecutive patients undergoing liver transplantation were treated with SBD starting 3 days prior to donor search and continuing for 21 days postliver transplantation. Selective bowel decontamination consisted of administering nonabsorbable antibiotics (Polymixin E, gentamicin, Nystatin) and a low bacterial diet. Surveillance cultures of the throat and rectum were obtained to monitor efficacy of selective bowel decontamination. In addition, in the posttransplant period, tracheal, wound, blood, and bile cultures were obtained to screen for gram-negative bacterial and Candida colonization and infection. Our baseline surveillance culture revealed that 29/30 (97%) of recipients were colonized with gram-negative aerobic bacteria and 16/30 (53%) with Candida. Three days after selective bowel decontamination was started, 26/30 (87%) were free of gram-negative bacteria, and 100% were free of Candida colonization of the gastrointestinal tract. There was a similar reduction in the oropharyngeal gram-negative aerobic bacteria and Candida colonization. In the first 30 days following liver transplantation, gram-negative infections were not diagnosed in any of our patients. Following discontinuation of SBD, recolonization of the gastrointestinal tract with gram-negative aerobic bacteria and Candida occurred within 5 days in 26/28 (90%) and 11/28 (35%), respectively. Our study suggests that prophylactive administration of nonabsorbable antibiotics will markedly reduce gram-negative aerobic bacterial and Candida colonization and appears to reduce the high incidence of infection related to these organisms in the early posttransplant period.

The role of the microbiology laboratory in the diagnosis and antimicrobial treatment of infective endocarditis.

The laboratory diagnosis of infective endocarditis is based on isolation of the etiologic agent from blood cultures. Major variables affecting the yield of microorganisms include the volume of blood cultured and the number of cultures performed, the atmosphere of incubation of cultures, and the frequency of examination and subculture of blood cultures. Bactericidal tests of antibiotics, singly and in combination, are important in determining the therapeutic regimen.

Blood cultures: principles and techniques.

Detecting the presence of microorganisms in blood is an important function of the clinical microbiology laboratory. With prompt isolation, identification, and antimicrobial susceptibility testing of bacterial isolates, the clinician can modify the selection and dosage of the antimicrobics used initially to treat a suspected septicemia. Principles and techniques for blood collection, culture, examination, and reporting are reviewed.

The in vitro spectrum of the cephalosporins.

The cephalosporins may currently be classified according to their relative susceptibility to beta-lactamases. Cefoxitin, cefamandole, cefatrizine, and cephanone are relatively resistant to the gram-negative beta-lactamases, whereas cephalothin, cefamandole, and cefoxitin are resistant to staphylococcal beta-lactamase. Although the inhibitory activity of cephalothin is representative of that of cephaloridine, cephalexin, cefazolin, cephapirin, cephacetrile, and cephradine, there are significant differences between its activity and that of cefoxitin, cefamandole, and cefatrizine, especially against Enterobacter, Serratia, indole-positive Proteeae, Bacteroides fragilis, and ampicillin-resistant Haemophilus influenzae.

Gentamicin-resistant Pseudomonas aeruginosa: Mayo Clinic Experience, 1970-1976.

During the period 1970 through 1976, there were 144 patients from whom gentamicin-resistant Pseudomonas aeruginosa (minimum inhibitory concentration [MIC], more than 5 microgram/ml) was isolated. In 20(21 percent) of the 95 patients who acquired such organisms within our institutions, the occurrence was considered clinically significant. Factors that favored the appearance of gentamicin-resistant P. aeruginosa included prolonged hospitalization, previous antibiotic treatment, increased gentamicin usage, underlying disease, and instrumentation (70 percent). Virulence of gentamicin-resistant isolates appeared less than that of susceptible organisms, with bacteremia due to these isolates occurring in only three cases. Resistant isolates with MICs for gentamicin of 8 to 16 microgram/ml were more susceptible to tobramycin than to amikacin, whereas isolates with MICs for gentamicin of 64 microgram/ml or greater were more susceptible to amikacin than to tobramycin. Eighty percent of all strains were susceptible to 128 microgram/ml or less of carvenicillin. Favorable results occurred in 12 or 13 cases treated with gentamicin plus carbenicillin, whereas treatment with either of these agents alone resulted in failure or relapse in 7 of 14 cases.

Antimicrobial susceptibility of gentamicin-resistant Pseudomonas aeruginosa.

The susceptibility of 41 strains of gentamicin-resistant Pseudomonas aeruginosa to tobramycin, sisomicin, netilmicin, amikacin, and carbenicillin was determined. Amikacin and carbenicillin exhibited the greatest activity against these strains and especially against those with a high level of resistance to gentamicin. Netilmicin exhibited little activity, whereas tobramycin and sisomicin were active against approximately two-thirds of the strains. Cross-resistance to tobramycin, sisomicin, and netilmicin was frequent.

Erythromycin: a microbial and clinical perspective after 30 years of clinical use (1).

Erythromycin is a macrolide that acts by inhibiting the translocation reaction during protein synthesis. Erythromycin is inactive against the Enterobacteriaceae and Pseudomonas aeruginosa except under alkaline conditions. Erythromycin is active against most gram-positive bacteria; some gram-negative bacteria, including Neisseria, Bordetella, Brucella, Campylobacter, and Legionella; and Treponema, Chlamydia, and Mycoplasma. The emergence of resistance to erythromycin is closely associated with its use and is often plasmid mediated. After its oral or parenteral administration, erythromycin diffuses readily into intracellular fluids and is actively concentrated intracellularly by polymorphonuclear leukocytes and alveolar macrophages.

Erythromycin: a microbial and clinical perspective after 30 years of clinical use (2).

Erythromycin, first introduced for clinical use 30 years ago, was found to be effective for the treatment of gram-positive bacterial infections. Emergence of resistance and the advent of penicillinase-resistant penicillins limited the use of erythromycin for serious staphylococcal infections; however, erythromycin remains among the drugs of choice for the treatment of acne, infections of the skin and soft tissues, streptococcal pharyngitis, bronchitis, pneumonitis, diphtheria, carriers of pertussis, and, when administered with a sulfonamide, otitis media. Erythromycin is the drug of choice for the empiric treatment of outpatients with pneumonitis. Erythromycin is also the drug of choice for the treatment of Legionella pneumonia and is effective therapy for Chlamydia infections. Other uses of erythromycin include prophylaxis for elective colon operations and treatment of Campylobacter enteritis, genitourinary infections, and some sexually transmitted diseases.

Microscopic and baceriologic analysis of expectorated sputum.

Samples of expectorated sputum were examined grossly and microscopically to determine their suitability for bacterial cultures. Microscopically, specimens were categorized according to the number of leukocytes and squamous epithelial cells (SEC) observed under low-power (times 100) in a Gram-stained smear. The mean number of species isolated was greater than 4 from specimens with more than 10 SEC per field, 2.7 from specimens with fewer than 10 SEC per field, and 2.4 from transtracheal aspirates. Oropharyngeal flora was isolated from nearly all of the specimens with more than 10 SEC per field, and potential pathogens were found in less than 15% of such specimens. The bacterial flora of specimens with fewer than 10 SEC per field closely resembled that of transtracheal aspirates.