Methane emissions from beef cattle grazing on semi-natural upland and improved lowland grasslands.

In ruminants, methane (CH4) is a by-product of digestion and contributes significantly to the greenhouse gas emissions attributed to agriculture. Grazed grass is a relatively cheap and nutritious feed but herbage species and nutritional quality vary between pastures, with management, land type and season all potentially impacting on animal performance and CH4 production. The objective of this study was to evaluate performance and compare CH4 emissions from cattle of dairy and beef origin grazing two grassland ecosystems: lowland improved grassland (LG) and upland semi-natural grassland (UG). Forty-eight spring-born beef cattle (24 Holstein-Friesian steers, 14 Charolais crossbred steers and 10 Charolais crossbred heifers of 407 (s.d. 29), 469 (s.d. 36) and 422 (s.d. 50) kg BW, respectively), were distributed across two balanced groups that grazed the UG and LG sites from 1 June to 29 September at stocking rates (number of animals per hectare) of 1.4 and 6.7, respectively. Methane emissions and feed dry matter (DM) intake were estimated by the SF6 tracer and n-alkane techniques, respectively, and BW was recorded across three experimental periods that reflected the progression of the grazing season. Overall, cattle grazed on UG had significantly lower (P<0.001) mean daily DM intake (8.68 v. 9.55 kg/day), CH4 emissions (176 v. 202 g/day) and BW gain (BWG; 0.73 v. 1.08 kg/day) than the cattle grazed on LG but there was no difference (P>0.05) in CH4 emissions per unit of feed intake when expressed either on a DM basis (20.7 and 21.6 g CH4 per kg DM intake for UG and LG, respectively) or as a percentage of the gross energy intake (6.0% v. 6.5% for UG and LG, respectively). However, cattle grazing UG had significantly (P<0.001) greater mean daily CH4 emissions than those grazing LG when expressed relative to BWG (261 v. 197 g CH4/kg, respectively). The greater DM intake and BWG of cattle grazing LG than UG reflected the poorer nutritive value of the UG grassland. Although absolute rates of CH4 emissions (g/day) were lower from cattle grazing UG than LG, cattle grazing UG would be expected to take longer to reach an acceptable finishing weight, thereby potentially off-setting this apparent advantage. Methane emissions constitute an adverse environmental impact of grazing by cattle but the contribution of cattle to ecosystem management (i.e. promoting biodiversity) should also be considered when evaluating the usefulness of different breeds for grazing semi-natural or unimproved grassland.

Nonhealing extraction site due to Actinomyces naeslundii in patient with AIDS.

There are many oral complications of human immunodeficiency virus infection. One of the infectious sequelae is contamination and delayed healing of the tooth extraction site. We report a case of a nonhealing extraction site in a patient with the acquired immunodeficiency syndrome. Histologic and microbiologic evaluation determined the causative species of bacterium to be Actinomyces naeslundii. Diagnosis and treatment are discussed.

Efficacy of pneumococcal vaccine in high-risk patients. Results of a Veterans Administration Cooperative Study.

We conducted a randomized, double-blind, placebo-controlled trial to test the efficacy of the 14-valent pneumococcal capsular polysaccharide vaccine in 2295 high-risk patients (patients with one or more of the following: age above 55 years and the presence of chronic cardiac, pulmonary, renal, or hepatic disease, alcoholism, or diabetes mellitus). Seventy-one episodes of proved or probable pneumococcal pneumonia or bronchitis occurred among 63 of the patients (27 placebo recipients and 36 vaccine recipients). Vaccine-serotype Streptococcus pneumoniae strains were recovered in association with 11 infections in the placebo group and 14 infections in the vaccine group. Pneumococcal infections occurred most frequently among patients with chronic pulmonary, cardiac, or renal diseases. Among vaccine recipients who subsequently had vaccine-type pneumonia or bronchitis, the majority did not make or sustain serum antibodies against their infecting organism in concentrations that were twice as high as the base-line values, or more than 400 ng of antibody nitrogen per milliliter, although their base-line levels were higher than those in subjects in whom infection did not develop. We were unable to demonstrate any efficacy of the pneumococcal vaccine in preventing pneumonia or bronchitis in this population. Our data suggest that chronically ill patients, who are most susceptible to infection, may have an impaired immune response to the pneumococcal vaccine.

Antibiotic-resistant isolates of Streptococcus pneumoniae from clinical specimens: a cluster of serotype 19A organisms in Brooklyn, New York.

Ten of 294 isolates of Streptococcus pneumoniae from patients enrolled in a Veterans Administration Cooperative Studies Program trial of pneumococcal vaccine efficacy were moderately resistant or resistant to penicillin. Nine of these organisms were serotype 19A isolated from patients at the Brooklyn (New York) V.A. Medical Center over an 18-month period (March 1983-November 1984). The minimal inhibitory concentration of penicillin for these pneumococci ranged from 1.0 to 2.0 micrograms/ml by the agar dilution technique and from 4.0 to 8.0 micrograms/ml by tube dilution. These organisms were resistant also to other beta-lactam antibiotics and to tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. They were sensitive to erythromycin, clindamycin, vancomycin, and rifampin. The epidemiological source of these isolates was not discovered. However, it is possible that a focus of multiple antibiotic-resistant serotype 19A S. pneumoniae is present in Brooklyn.

Ceftazidime therapy of infections caused by Enterobacteriaceae and Pseudomonas aeruginosa.

Sixteen patients with serious Gram-negative bacillary infections were treated with intravenous ceftazidime, 2 g every 8 h. The majority of patients had bacteraemia or pneumonitis or both. Ten patients were cured and six improved. Seven of ten patients infected with Pseudomonas aeruginosa were cured, and three improved. No adverse reactions occurred. Four strains of Ps. aeruginosa became resistant to ceftazidime in patients who were cured or improved clinically. Ceftazidime is effective as single drug therapy for serious Gram-negative infections, including those due to Ps. aeruginosa.

Isolation of Klebsiella ozaenae and Klebsiella rhinoscleromatis in a general hospital.

Klebsiella ozaenae and Klebsiella rhinoscleromatis are uncommon organisms usually associated with granulomatous or necrotizing disease of the upper airways. Seven patients are described, non of whom had characteristic clinical manifestations of infection with these species. The organisms were recovered from mixed wound infections or sputum of five patients, and from the blood of three patients. Antibiotic sensitivity patterns were unusual and included susceptibility to both ampicillin and carbenicillin.

Amikacin therapy for serious gram-negative infection.

Amikacin sulfate was administered to 18 patients for the treatment of 19 severe infections. Seventeen infections were caused by gentamicin-resistant Gram-negative bacilli, and 13 patients were bacteremic. Bacteriologic cure was attained in all but one instance, and effective serum, bile, and pleural fluid drug levels were demonstrated. Drug-related fever occurred in one patient, and another experienced a maculopapular rash and monilial intertrigo. In three patients, reversible renal toxicity developed, but none had clinical evidence of ototoxicity. Amikacin sulfate in a dose of 15 mg/kg/day is an effective antibiotic for the treatment of serious Gram-negative infections, particularly those due to gentamicin-resistant organisms.

Resistance of Staphylococcus aureus to semisynthetic penicillins and cephalothin.

Six strains of Staphylococcus aureus resistant to semisynthetic penicillins were recovered from clinical sources during a two-month period. Resistance was detected by standard disk sensitivity tests at 37 C. Two resistant strains were responsible for infections (one of which was fatal), and five strains were susceptible only to phage type 92. All of the strains produced penicillinase, which did not destroy oxacillin, and each was resistant to oxacillin at low inocula. Relative resistance to cephalosporin was demonstrable by the tube dilution assay but not by standard disk tests. The strains susceptible to phage type 92 were susceptible to vancomycin and to the synergistic action of oxacillin or cephalothin plus gentamicin.

R factors in gentamicin-resistant organisms causing hospital infection.

An abrupt increase in gentamicin-resistant isolates was noted in the Manhattan Veterans Administration Hospital in 1973 and 1974. Bacteraemic infection occurred in 17 patients, 9 of whom died. R factors mediating gentamicin resistance were demonstrated in 34 of 36 strains. Organisms from 9 of 11 patients transferred a resistance pattern common to all other isolates from that patient, suggesting in-vivo interbacterial spread of the R factor.

Nosocomial infection caused by gentamicin-resistant, streptomycin-sensitive Klebsiella.

Resistance to gentamicin increased abruptly among nosocomial isolates of Klebsiella and Enterobacter at the New York Veterans Administration Hospital in 1973 and 1974. A prospective clinical survey revealed a greater incidence of true infection caused by Klebsiella than by Enterobacter. The initial site of implantation was usually the urinary tract. Multiple serotypes were involved, and one of these was found in rectal swabs of patients treated with antibiotics. Gentamicin resistance declined rapidly after the use of this antibiotic was restricted and increased several months after restrictions were removed. Gentamicin-resistant strains of Klebsiella were uniformly sensitive to amikacin; 75% were sensitive to polymyxin B and 70% to streptomycin. Antibiotic sensitivity among gram-negative pathogens might be preserved by a program in which the use of highly effective agents is periodically rotated.

Diplococcus pneumoniae. Cellulitis in drug addicts.

Cellulitis caused by Diplococcus pneumoniae was diagnosed in two heroin users. To our knowledge, this medical emergency, clinically indistinguishable from deep fasciitis of pyomyositis, has not previously been reported as having been caused by the agent identified in these two patients.