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Frame Lake, a small (88.4 ha), shallow (

Canada’s Northwest Territories (NWT) is currently the focus of significant exploration and development activity. In particular, increased global demand for oil and gas resources has resulted in an escalation in the search for hydrocarbon deposits. Canada’s north is a landscape defined by water where large numbers of pristine water bodies still exist in remote areas. Northern development activities conducted in these areas will affect these sensitive aquatic ecosystems that support important fish and fish habitat. Fishes in low productivity northern systems grow slowly and mature late, making them particularly sensitive to environmental perturbations. The fishery resources of the NWT are an integral component of our northern ecosystems, and are of significant economic and cultural importance to northern people. By necessity, linear developments constructed in the NWT, such as roads, seismic lines, and pipelines, intersect lakes, rivers, and streams. This paper discusses linear development activities and their impacts on northern fishes, with a focus on oil and gas developments. Once a target area is identified, the development of northern oil and gas reserves typically follows a predictable sequence of events: (i) construction of temporary access roads into the exploration area to conduct seismic surveys to delineate reserves; (ii) exploration well(s) are drilled to assess the potential of the deposit; (iii) if the deposit is of economic interest, then production wells are developed and gathering systems constructed, often coupled with additional transportation infrastructure; (iv) a pipeline is then built to move the hydrocarbons southward to processing facilities; and (v) after the reserve is depleted, closure of all associated infrastructure is conducted and the site is remediated. The main stressors from these activities that may impact fish and aquatic ecosystems include sediment transport to water bodies, noise and pressure impacts from the use of explosives, water withdrawal, obstructions to flow and fish passage, removal of in-stream structure and riparian vegetation, enhanced access and fisheries exploitation, and contaminant spills. These stressors can adversely affect fish directly (e.g., through direct toxicity associated with exposure to elevated contaminants) or indirectly (e.g., through habitat degradation). Such impacts on fish can vary in severity, and on temporal and spatial scales, depending on the nature and extent of the disturbance. These activities can have cumulative impacts and can be exacerbated by natural or indirect stressors, such as a changing climate or forest fires. Appropriate baseline monitoring needs to be conducted, prior to development, to allow for appropriate mitigation to be employed and sound and responsible resource management decisions to be made within an adaptive management framework.

Canada's lakes and rivers account for approximately 20% of the world's freshwater resources, with much of this water held in large northern lakes and their expansive watersheds. These lakes have been the focus of curiosity, beginning with early exploratory expeditions of pre-confederation Canada with scientific investigation peaking in the 1950s, after which interest dropped precipitously and remained low for the next 50 years. However, since the year 2000 relative scientific output on the large lakes of northern Canada (based on published journal articles) has doubled, indicating a renewed interest in research on these important water bodies and their watersheds. In 2014, for the first time in the 67-year history, the Canadian Conference of Fisheries Research and its co-host the Society of Canadian Limnologists held their annual meeting above the 60th parallel. As a tribute to that accomplishment, we present fifteen papers showcasing recent multidisciplinary research focusing on Canada's large northern lakes or occurring within their watersheds. We believe that these northern aquatic ecosystems offer researchers boundless potential for scientific investigation and discovery. With the integrity of freshwater resources being a fundamental global concern, the importance of continuing and increasing research on northern freshwater resources cannot be understated.

Detecting beta-lactamase-mediated carbapenem resistance among Klebsiella pneumoniae isolates and other Enterobacteriaceae is an emerging problem. In this study, 15 blaKPC-positive Klebsiella pneumoniae that showed discrepant results for imipenem and meropenem from 4 New York City hospitals were characterized by isoelectric focusing; broth microdilution (BMD); disk diffusion (DD); and MicroScan, Phoenix, Sensititre, VITEK, and VITEK 2 automated systems. All 15 isolates were either intermediate or resistant to imipenem and meropenem by BMD; 1 was susceptible to imipenem by DD. MicroScan and Phoenix reported 1 (6.7%) and 2 (13.3%) isolates, respectively, as imipenem susceptible. VITEK and VITEK 2 reported 10 (67%) and 5 (33%) isolates, respectively, as imipenem susceptible. By Sensititre, 13 (87%) isolates were susceptible to imipenem, and 12 (80%) were susceptible to meropenem. The VITEK 2 Advanced Expert System changed 2 imipenem MIC results from >16 ?g/mL to

Seismic airguns produce considerable amounts of acoustic energy that have the potential to affect marine life. This study investigates the effects of exposure to a 730 in.3 airgun array on hearing of three fish species in the Mackenzie River Delta, the northern pike (Esox lucius), broad whitefish (Coregonus nasus), and lake chub (Couesius plumbeus). Fish were placed in cages in the 1.9 m of water and exposed to five or 20 airgun shots, while controls were placed in the same cage but without airgun exposure. Hearing in both exposed and control fish were then tested using the auditory brainstem response (ABR). Threshold shifts were found for exposed fish as compared to controls in the northern pike and lake chub, with recovery within 24 hours of exposure, while there was no threshold shift in the broad whitefish. It is concluded that these three species are not likely to be substantially impacted by exposure to an airgun array used in a river seismic survey. Care must be taken, however, in extrapolation to other species and to fishes exposed to airguns in deeper water or where the animals are exposed to a larger number of airgun shots over a longer period of time.

Barriers to effective diagnostic testing for human immunodeficiency virus type 1 (HIV-1) infection can be reduced with simple, reliable, and rapid detection methods. Our objective was to determine the accuracy, sensitivity, and specificity of a new rapid, lateral-flow immunochromatographic HIV-1 antibody detection device. Preclinical studies were performed using seroconversion, cross-reaction, and interference panels, archived clinical specimens, and fresh whole blood. In a multicenter, prospective clinical trial, a four-sample matrix of capillary (fingerstick) whole-blood specimens and venous whole blood, plasma, and serum was tested for HIV-1 antibodies with the Efoora HIV rapid test (Efoora Inc., Buffalo Grove, IL) and compared with an enzyme immunoassay (EIA) (Abbott Laboratories) licensed by the Food and Drug Administration. Western blot and nucleic acid test supplemental assays were employed to adjudicate discordant samples. Preclinical testing of seroconversion panels showed that antibodies were often detected earlier by the rapid test than by a reference EIA. No significant interference or cross-reactions were observed. Testing of 4,984 archived specimens yielded a sensitivity of 99.2% and a specificity of 99.7%. A prospective multicenter clinical study with 2,954 adult volunteers demonstrated sensitivity and specificity for the Efoora HIV rapid test of 99.8% (95% confidence interval [CI], 99.3 and 99.98%) and 99.0% (95% CI, 98.5 and 99.4%), respectively. Reactive rapid HIV-1 antibody detection was confirmed in 99.6% of those with a known HIV infection ( n = 939), 5.2% of those in the high-risk group ( n = 1,003), and 0.1% of those in the low-risk group ( n = 1,012). For 21 (0.71%) patients, there was discordance between the results of the rapid test and the confirmatory EIA/Western blot tests. We conclude that the Efoora HIV rapid test is a simple, rapid assay for detection of HIV-1 antibodies, with high sensitivity and specificity compared to a standardized HIV-1 EIA.

Study objectives To investigate the dramatic rise innumber of Mycobacterium xenopi isolates identified inour mycobacteriology laboratory, and to determine if this increase wasdue to emerging clinical pathology or to changes in culturetechnique. Design Retrospective chart and laboratoryreview. Setting University-affiliated tertiary-carecity hospital. Patients Eighty-one patients with asingle culture positive for M xenopi from 1975 to 1994(period 1), and 47 patients with two or more cultures positive from1994 to 1998 (period 2). Interventions The Bellevuemycobacteriology laboratory changed the culture medium from solidLowenstein-Jensen medium (used from 1975 to 1990) to the Septi-CheckAFB System (Becton-Dickinson; Glencoe, MD; used from 1991 to 1994), tothe Mycobacteria Growth Indication Tube (MGIT; Becton-Dickinson; usedfrom 1995 to 1998). Measurements and results Werecovered 29 M xenopi isolates from 1975 to 1990, 12isolates from 1991 to 1994, and 381 isolates from 1995 to 1998. Wesubsequently identified and reviewed the medical records of all 81patients who were culture positive for M xenopi from1975 to 1994 (period 1), and 46 patients who had two or more isolatesculture positive for M xenopi from 1995 to 1998 (period2). For period 1, 75% of the subjects were male, 80% were minority,and at least 43% were HIV positive. Only one patient had clinical M xenopi lung disease during this period. For period 2,79% of the subjects were male, 83% were minority, and at least 58%were HIV positive; two additional patients were identified who hadclinical M xenopi lung disease. Conclusions The dramatic increase in Mxenopi isolates noted in our hospital was due to a moresensitive laboratory isolation technique, rather than a true increasein clinical disease. Other hospitals utilizing MGIT systems formycobacterial recovery should interpret positive Mxenopi cultures with caution.

In the mid 1930s, A.G. Huntsman hypothesized that in the Miramichi River, New Brunswick, predation by kingfishers and American mergansers upon Atlantic salmon (Salmo salar) parr became especially severe in years of low July–August rainfall, these years being reflected 3 y later by reduced commercial catches. Huntsman attempted to demonstrate this predation effect with visual comparisons of aligned graphs of July–August rainfall for the city of Chatham, N.B., and commercial landings of 2½-sea-y salmon in Northhumberland County at the mouth of the Miramichi River. With detrended fishery data, and rainfall data augmented by additional weather stations, we confirmed that Huntsman's 3 y alignment provides the strongest and most significant correlation available in these data. We found that Huntsman's 2-mo correlation is strengthened by inclusion of September rainfall, and is strongest as a 5-mo May-to-September correlation. In the discussion, we distinguish between Huntsman's 3-y correlation and the b...

The transmission of perinatal hepatitis C virus (HCV) infection was studied retrospectively in 62 infants born to 54 HCV- and human immunodeficiency virus (HIV)-coinfected women enrolled in a prospective natural history study of HIV transmission. Infant HCV infection was assessed by nested RNA polymerase chain reaction. The overall rate of vertical HCV transmission was 16.4% (9/62). Most HCV-infected children did not develop antibodies to HCV. The rate of HCV infection was higher among HIV-infected infants (40%) than among HIV-uninfected infants (7.5%; odds ratio, 8.2; P = .009). This difference in transmission was not related to differences in maternal HCV load, as measured by branched DNA assay, or mode of delivery. Why HIV-infected infants of HCV- and HIV-coinfected women have significantly higher rates of perinatal HCV transmission remains to be elucidated. The rate of HCV transmission in HIV-uninfected infants of HCV- and HIV-coinfected women is similar to that reported for infants born to HIV-seronegative mothers.

Air guns are an energy source commonly used by the oil and gas industry for seismic exploration, particularly in marine environments. Exposure to air gun noise has been shown to negatively impact marine fishes (e.g., McCauley et al. 2003); however, little is known about the potential impacts on fishes in freshwater systems. A proposal to use air guns for a seismic survey along the Mackenzie and Liard Rivers (∼1,200 km) in the Northwest Territories (NWT) led to considerable public and regulatory concern. As a result, the Canadian Department of Fisheries and Oceans (DFO) required the proponent to validate their prediction that the project will have no impacts on fish. The proponent conducted a study that showed no acute mortality associated with air gun use, although some stunning was observed in caged fish closest (2 m) to the air gun blasts (Cott et al. 2003). Outstanding data gaps associated with sublethal impacts of air gun noise (e.g., physical damage, stress, herding, and hearing loss) prompted the DFO to initiate a study, in collaboration with academic partners, to assess these impacts on northern fish in a riverine setting. The project was split into two components: 1) physiological impacts on fish hearing and ear damage and 2) behavioral impacts on free-swimming fishes.

Potential impacts on aquatic life associated with anthropogenic underwater noise are an emerging concern worldwide (Popper et al. 2005). In the Northwest Territories (NWT), Canada, there has been an increased interest in natural resources development and the potential for impacts to both marine and freshwater areas. Fish (including marine mammals and other aquatic life) and their habitats are managed by Canada’s Department of Fisheries and Oceans (DFO) under the federal Fisheries Act and the Oceans Act. The DFO reviews project proposals, assesses potential impacts, provides scientific and regulatory advice based on the current state of knowledge, identifies existing data gaps, and initiates steps to address them. If residual impacts are expected with mitigative measures in place, the DFO is able to account for and authorize impacts under the Fisheries Act. Here we identify the types of noise-related impacts that are pertinent to the species and industry activities in the NWT and how these concerns are being addressed by the DFO.

We recently observed a striking increase in multidrug-resistant tuberculosis (MDR-TB) among patients admitted to the Chest Service at Bellevue Hospital Center in New York. We reviewed the laboratory susceptibility test results of 4,681 tuberculosis (TB) cases over the past 20 years, Combined resistance to isoniazid and rifampin increased from 2.5 percent in 1971 to 16 percent in 1991 with higher rates noted for individual drugs. We reviewed the medical records of 100 patients with drug-resistant TB, finding that these individuals were predominantly less than 40 years of age, minority, male, jobless, undomiciled, with a high percentage of drug abuse and human immunodeficiency virus infection. We conclude that the epidemics of AIDS and TB are complicated by a third epidemic of MDR-TB. This third epidemic requires urgent attention to achieve more rapid diagnosis, to develop new therapeutic regimens, and to address the social and hospital environment ot care for these individuals.

Objective: Although the incidence of reported cases of toxic shock syndrome (TSS) has declined in recent years, the disease continues to occur in menstruating women using the newer, less-absorbent tampons or barrier contraceptives. Extant tampons and other vaginal devices were tested for the ability to induce TSS toxin-1 (TSST-1) by a TSS strain of Staphylococcus aureus MN8, a known high-toxin producer. Tested for the first time were 20 varieties of tampons, including 2 all-cotton brands newly introduced in the United States, a polyurethane contraceptive sponge, a latex diaphragm, and a polymer menstrual collection cup.Methods: All products were washed in sterile distilled water prior to use to reduce the effect of leachable chemicals. Duplicate experiments with unwashed products were also performed. Entire tampons and other test products were immersed in brain heart infusion broth plus yeast extract (BHIY) and inoculated with S. aureus MN8, a known TSST-1 producer. After incubation, the culture supernatants were assayed for TSST-1 by gel immunodiffusion.Results: Except for all-cotton tampons, greater amounts of TSST-1 were detected in the supernatant fluid of washed tampons than detected in those which were not washed. While TSST-1 levels in unwashed non-cotton tampons ranged from 0.5 to 8 μg/ml, when these products were washed, TSST-1 levels increased to 2–32 μg/ml. In all-cotton tampons, whether washed or not, there was no detectable TSST-1.Conclusions: The propensity for all-cotton tampons not to amplify TSST-1 in vitro suggests they would lower the risk for tampon-associated TSS.

Five hundred urine specimens were selected at random and screened for bacteriuria by a DNA probe method, FlashTrack (Gen-Probe, San Diego, Calif.), and an automated bioluminescence method, UTIscreen (Los Alamos Diagnostics, Los Alamos, N.M.), and the results were compared with those of the semiquantitative plate culture method. The performance of each test versus culturing was evaluated at colony counts of greater than or equal to 10(4), greater than or equal to 5 x 10(4), and greater than or equal to 10(5) CFU/ml. Since the interpretive breakpoint of each test was user selectable, the results were reported as receiver operator characteristic curves. Optimum interpretive breakpoints were determined for each test at each colony count by calculating a performance index that emphasized sensitivity over specificity in a 70:30 ratio. Although both tests had less-than-optimal sensitivities and specificities, the performance of FlashTrack was significantly better than that of UTIscreen at two of the three colony counts (10(4) and 10(5) CFU/ml); however, FlashTrack costs more and is a labor-intensive procedure. Neither method was evaluated for the detection of colony counts of less than 10(4) CFU/ml.

An earlier study examined the effects of exposure to seismic air guns on the hearing of three species of fish from the Mackenzie River Delta in Northern Canada [Popper et al. (2005). "Effects of exposure to seismic airgun use on hearing of three fish species," J. Acoust. Soc. Am. 117, 3958-3971]. The sound pressure levels to which the fishes were exposed were a mean received level of 205-209 dB re 1 microPa (peak) per shot and an approximate received mean SEL of 176-180 dB re 1 microPa(2) s per shot. In this report, the same animals were examined to determine whether there were effects on the sensory cells of the inner ear as a result of the seismic exposure. No damage was found to the ears of the fishes exposed to seismic sounds despite the fact that two of the species, adult northern pike and lake chub, had shown a temporary threshold shift in hearing studies.

Leprosy or Hansen's disease is a chronic infectious disease caused by an acid-fast bacillus, Mycobacterium leprae (M. leprae). The bacilli proliferate in macrophages infiltrating the skin and gain entry to the dermal nerves via the laminar surface of Schwann cells where they replicate. After entry, the Schwann cells proliferate and then die. Conclusive identification of M. leprae DNA in a sample can be obtained by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the heat shock 65 gene (hsp65). Molecular epidemiology will make it possible to study the global distributions of M. leprae, explore the relationship between genotypes-incidence rates, mode of transmission, and the type of disease (tuberculoid vs. lepromatous). We amplified DNA using PCR for the hsp65 gene from 24 skin lesions from patients diagnosed with various types of leprosy. Fifteen out of 24 were positive for the hsp65 gene. Digestion with HaeIII-PAGE for the RFLP confirmation of the presence of M. leprae DNA showed the typical pattern in 5 out of 24 and 2 novel patterns in 10 out of 24 patients. We confirmed the presence of M. leprae DNA by sequencing the genes for gyraseA or B and folP, which contained only M. leprae specific single nucleotide polymorphisms (SNPs). Thus, we describe novel hsp65 RFLPs for M. leprae found in a high frequency making them ideal for future epidemiology and transmission studies.

Measurement of human immunodeficiency virus type 1 (HIV-1) plasma RNA levels using Roche AMPLICOR version 1.5 (HIV RNA) is an integral part of monitoring HIV-infected patients in industrialized countries. These assays are currently unaffordable in resource-limited settings. We investigated a reverse transcriptase (RT) assay as a less expensive alternative for measuring viral burden that quantifies RT enzyme activity in clinical plasma samples. A comparison of RT and HIV RNA assays was performed on 29 paired plasma samples from patients living in the United States and 21 paired plasma samples from patients living in Cameroon. RT levels correlated significantly with plasma HIV RNA viral loads in plasma from U.S. patients ( r = 0.898; P < 0.001) and Cameroonian patients, a majority of whom were infected with HIV-1 clade type CRF02_AG ( r = 0.669; P < 0.01). Among 32 samples with HIV viral load of >2,000 copies/ml, 97% had detectable RT activity. One Cameroon sample had undetectable RNA viral load but detectable RT activity of 3 fg/ml. The RT assay is a simple and less expensive alternative to the HIV RNA assay. Field studies comparing these assays in resource-limited settings are warranted to assess the practicality and usefulness of this assay for monitoring HIV-infected patients on antiretroviral therapy.

Both Bartonella quintana and Coxiella burnetii are known to cause of blood culture negative endocarditis. In such case, the diagnosis is usually established by serology. A case of Bartonella quintana endocarditis is described where the serology was falsely positive for Coxiella burnetii. This case demonstrates the difficulty in distinguishing these two etiologic agents by routine serologic testing.

A Campylobacter species was isolated from blood from a febrile patient with precursor T-cell acute lymphoblastic leukemia, and after antibiotic treatment, a similar bacterium was isolated from blood 37 days later. Although phenotypic testing did not definitively identify the organisms, molecular analysis indicated that they were the same strain of Campylobacter fetus subsp. fetus and were of reptile origin.

We demonstrate that Bacillus anthracis may be detected from a formalin-fixed, paraffin-embedded biopsy specimen, even after the patient has received antibiotic treatment. Although traditional PCR methods may not be sufficiently sensitive for anthrax detection in such patients, cycle numbers can be increased or PCR can be repeated by using an aliquot from a previous PCR as the template.

OBJECTIVE AND IMPORTANCE: Although Propionibacterium acnes is a common inhabitant of human skin, it is an uncommon pathogen in postoperative infections. We report three cases of postoperative wound infection/osteomyelitis caused by P. acnes. CLINICAL PRESENTATION: Three patients underwent craniotomy for a supratentorial meningioma and had a dural allograft at the time of closure. The patients presented several weeks after surgery with clinical evidence of a wound infection. INTERVENTION: All patients were diagnosed with P. acnes infection and treated for this pathogen with appropriate antibiotics. The bone flap was removed in two patients. After antibiotic therapy, all patients demonstrated no further evidence of infection. CONCLUSION: To our knowledge, this is the first published report of P. acnes infection in patients with a dural substitute. The source of infection cannot be confidently ascertained; however, two patients had strains of P. acnes from one brand of graft, which were indistinguishable by pulsed field gel electrophoresis typing.

We evaluated the BACTEC MGIT 960 system, which is a fully automated, noninvasive system for the growth and detection of mycobacteria with a capacity to incubate and continuously monitor 960 7-ml culture tubes. We studied 3,330 specimens, 2,210 respiratory and 1,120 nonrespiratory specimens, collected from 2,346 patients treated at six sites. Processed specimens were inoculated into the BACTEC MGIT 960 and BACTEC 460 TB systems, as well as onto Lowenstein-Jensen slants and Middlebrook 7H11/7H11 selective plates. From all culture systems, a total of 362 isolates of mycobacteria were recovered; these were recovered from 353 specimens collected from 247 patients. The greatest number of isolates of mycobacteria (289, or 80% of the 362 isolates) was recovered with the BACTEC MGIT 960, followed by the BACTEC 460 TB (271, or 75%) and solid media (250, or 69%). From all culture systems a total of 132 isolates of Mycobacterium tuberculosis complex were recovered. The greatest number of isolates of M. tuberculosis complex was recovered when liquid medium was combined with conventional solid media; the number recovered with BACTEC 460 TB plus solid media was 128 (97%), that recovered with BACTEC MGIT 960 plus solid media was 121 (92%), that recovered with BACTEC 460 TB was 119 (90%) and that recovered with all solid media combined was 105 (79%). The recovery with BACTEC MGIT 960 alone was 102 (77%). The mean times to detection (TTD) for M. tuberculosis complex were 14.4 days for BACTEC MGIT, 15.2 days for BACTEC 460 TB, and 24.1 days for solid media. The numbers of isolates of Mycobacterium avium complex (MAC) recovered were 172 (100%) for all systems, 147 (85%) for BACTEC MGIT 960, 123 (72%) for BACTEC 460 TB, and 106 (62%) for all solid media combined. The TTD for MAC in each system were 10.0 days for BACTEC MGIT 960, 10.4 days for BACTEC 460 TB, and 25.9 days for solid media. Breakthrough contamination rates (percentages of isolates) for each of the systems were 8.1% for BACTEC MGIT 960, 4.9% for BACTEC 460 TB, and 21.1% for all solid media combined.

Clinical isolates of Mycobacterium avium-intracellulare complex (MAIC) were tested against ciprofloxacin using adenosine triphosphate (ATP) release as measured by bioluminescence. The results were compared with conventional minimal inhibitory concentrations determined in liquid medium and with minimal bactericidal concentrations determined by an agar plating method. Good correlation was observed between methods when the ATP release was measured after only 5 days of incubation. The bioluminescence method was objective and has the potential for being fully automated.

Mycobacterium avium-intracellulare complex (MAC) is a ubiquitous environmental microorganism whose pathogenicity ranges from innocuous colonization to disease, in immunocompetent as well as immunocompromised individuals. We sought to determine the clinical significance of MAC in sputum cultures of patients with pulmonary tuberculosis (TB). A retrospective analysis between January 1994 and March 1995 at Bellevue Hospital Center revealed both Mycobacterium tuberculosis and MAC in 35 patients (11% of all patients with TB). Of 27 patients reviewed, 52% were HIV-1 infected (median CD4 + 25 cells per microliter). Radiographic manifestations in patients with TB and MAC were similar to those seen in patients with TB alone. Both mycobacteria were cultured primarily from respiratory sources. M tuberculosis was usually cultured first or concurrent with MAC, and in nearly all cases, both species were recovered within 2 months of each other. Most patients improved clinically, bacteriologically, and radiographically with standard antituberculous therapy, except those with advanced AIDS, multidrug-resistant TB (MDR-TB), or disseminated MAC. We conclude that recovery of MAC in sputum is common in patients with pulmonary TB, regardless of HIV-1 infection, MDR-TB, or other clinical, bacteriologic, or radiographic attributes. MAC cultivation in most of these patients likely represents transient colonization, and in most cases is not clinically significant.

Medicinal leeches are used to control venous congestion. Aeromonas in the leech gut are essential for digestion of blood. This case report describes a patient who had Aeromonas bacteremia develop after leeching. He had an injury to his hand that required replantation of his thumb. Following the surgery, leech therapy was started with ampicillin-sulbactam prophylaxis. Sepsis developed. Blood cultures were positive for Aeromonas that were resistant to ampicillin-sulbactam. The antibiotic was changed to ciprofloxacin on the basis of the sensitivity profile of the organisms. Cultures from the leech bathwater confirmed it as the source of the Aeromonas. Clinicians who use leech therapy must be aware that leeches can harbor Aeromonas species resistant to accepted prophylactic antibiotics and that sepsis may occur.

To limit nosocomial spread of respiratory syncytial virus (RSV) infection, a longitudinal intervention trial was instituted. Nasal secretions or washes were screened for RSV antigen by enzyme-linked immunosorbent assay, and patients were assigned to an RSV-infected or an RSV-uninfected cohort. The baseline (preintervention) rate of 7.17 nosocomial cases of RSV per 1000 patient-days of care was used for comparison. Despite continued infections in the community after screening was initiated, there were no cases of RSV infection in 1880 patient-days of care for 3 months (p = 0.039). During the fourth month, an RSV-infected child was erroneously assigned to the RSV-uninfected cohort, and three nosocomial cases occurred--5.33/1000 patient-days of care (p = 0.286). Overall, there were three nosocomial RSV infections in 2443 patient-days of care in the 1987 season after screening was introduced--1.23/1000 patient-days of care (p = 0.026). In the subsequent RSV season, there was one nosocomial case--0.461/1000 patient-days of care for 3 months (p = 0.0074). During the same period, nosocomial cases of RSV were observed in the pediatric and neonatal intensive care units, where assignment to a cohort was not possible. We conclude that entry into a cohort at the time of admission, on the basis of prospective RSV screening by enzyme-linked immunosorbent assay, effectively reduces nosocomial transmission of RSV.

A rapid latex agglutination (LA) method was evaluated in 2401 consecutive pediatric patients presenting to an emergency service with suspected group A beta-hemolytic streptococcal pharyngitis. LA tests were performed by the treating physicians, who were not blinded to the clinical condition of the children and who made therapeutic decisions based on the results of the tests. When compared with anaerobic culture, the LA method had a sensitivity of 91%, a specificity of 82%, and a positive predictive value of 43%. There was a marked seasonal variation in the positive predictive value: 62% in winter and 16% in summer. However, even in peak streptococcal pharyngitis season (January to March), basing therapy on a positive LA test leads to the unnecessary treatment of a large number of patients. Therefore, we cannot recommend the routine performance of this test by all practitioners in all clinical settings.

Seismic airguns produce considerable amounts of acoustic energy that have the potential to affect marine life. This study investigated the effects of exposure to an airgun array in the Mackenzie River Delta on the hearing of three fish species: northern pike (Esox lucius), broad whitefish (Coregonus nasus), and lake chub (Couesius plumbeus). Fish were placed in cages in 1.9 m of water and exposed to 5 or 20 airgun shots, while controls were placed in the same cage but without airgun exposure. Hearing in both exposed and control fish were then tested using auditory evoked potentials (AEPs). Threshold shifts were found for exposed fish as compared to controls in the northern pike and lake chub, with recovery within 24 h of exposure, while there was no threshold shift in the broad whitefish. It is concluded that these three species are not likely to be substantially impacted by exposure to a 2D airgun array used in a river seismic survey. Care must be taken in extrapolation to other species in other environments and to fishes exposed to airguns in 3D tests or where the animals are exposed to a larger number of airgun shots over a longer period of time.

Corynebacterium diphtheriae infection is still epidemic in the states of the former Soviet Union. To date, no cases have been exported to the United States [1]. An Uzbek national developed severe pharyngitis shortly after entering the United States. Recovery of Corynebacterium pseudodiphtheriticum complicated the diagnostic process. The ubiquity of this organism should be more widely recognized. Three days after arriving in the United States from his native Uzbekistan, a 32-year-old airline crew member was admitted to the hospital with a progressively severe sore throat and dysphagia of 2 days' duration. He noted that he had received "all" immunizations as a child but did not recall any specific details. He was unaware of recent illness in his family, the airline crew, or close contacts. His temperature was 102?F. His tonsils were enlarged bilaterally, and a grayish-white exudate extended from the tonsil to the posterior pharyngeal wall (figure 1). The uvula and soft palate were erythematous and edematous, and there was tender cervical lymphadenopathy. The leukocyte count was 22,000/4tL. Duplicate rapid screening tests for group A streptococci were negative. Epstein-Barr virus IgM viral capsid antigen titers were < 1:10. The patient's history and the findings raised the possibility of imported diphtheria. After consultation with the local health department and Centers for Disease Control and Prevention, 40,000 units of equine diphtheria antitoxin was administered intravenously. Treatment with im procaine penicillin G (600,000 units every 12 hours) was given and changed to that with oral erythromycin after the patient's clinical condition rapidly improved within 24 hours. Cultures of the pharyngeal exudate yielded only a mixture of normal flora. Cultures of nasopharyngeal secretions yielded a heavy, pure growth of pale grayish-white colonies on blood agar and black colonies with a gray halo on Tindale's agar. A gram stain showed gram-positive club-shaped bacilli forming "Chinese letters," which were consistent with C. diphtheriae. On biochemical testing, however, the organism was identified as C. pseudodiphtheriticum.

The incidence of amikacin resistance among gram-negative bacilli isolated at the New York V.A. Medical Center increased from 2.0% to greater than 7% during an 18-month period from January 1980 to July 1981. This increase coincided with a threefold increase in amikacin use at this institution. The amikacin-resistant (AKR) isolates most frequently recovered in 1981 were species of Klebsiella, Serratia, and Pseudomonas. These organisms were recovered from multiple sites, including urine, sputum, wounds, blood, peritoneal fluid, and pleural fluid. The amikacin-modifying enzyme 6'-N-acetyltransferase was detected in 27 (67.5%) of 40 randomly selected AKR isolates. These data indicate that resistance to amikacin in this hospital is enzymatically mediated in most strains of AKR Klebsiella and Serratia and in about one-third of AKR strains of P. aeruginosa. This finding supports the conclusion that amikacin resistance is enhanced by the pressure of increased amikacin use.

Studies to date have indicated that nutritionally-variant streptococci (NVS) causing bacterial endocarditis are frequently inhibited but not killed by low concentrations of penicillin. We report a patient with endocarditis due to a NVS strain which was killed in vitro by penicillin at a concentration of 0.09 μ g/ml. Despite therapy with intravenous penicillin for four weeks, the infection relapsed and was then cured by combined penicillin-gentamicin in therapy. In vitro studies demonstrated a synergistic effect of these two antibiotics. This experience suggests that combination therapy with penicillin and an aminoglycoside may be required for cure of all cases of nutritionally-variant streptococcal endocarditis regardless of in vitro susceptibility to penicillin.

Super-absorbent tampons and an exotoxin of Staphylococcus aureus have been associated with the recent emergence of toxic shock syndrome (TSS). In the majority of cases, when a TSS strain of S. aureus was cultivated in the presence of various tampons and a contraceptive sponge, increased amounts of toxic shock syndrome toxin-1 (TSST-1) were observed to be produced into the blood medium by the bacterium. The amplification of toxin by these products adds support to the epidemiologic data in establishing the causal link between tampons and TSS.

Instrument development in microbiology has focused on automating the traditional process of bacterial identification using growth-dependent technology. With the advent of genetic tools, advances in immunology, and engineering innovations microbiologists are moving away from the traditions of culture-dependent technology and are concentrating on the development of rapid, specific, nongrowth-dependent systems with a potential for automation.

Pulmonary aspergillosis developed in a 62-year-old man with acute myelogenous leukemia. Therapy with amphotericin B and 5-fluorocytosine was begun. Synergy between amphotericin B and rifampin was demonstrated in vitro, and therapy with firampin replaced 5-fluorocytosine. Progressive clearing of the pulmonary lesion ensued, suggesting in vivo efficacy as well. Further studies of patients utilizing this regimen are warranted.

The large number of deaths in newborns resulting from invasive early-onset group B streptococcal (GBS) disease constitutes a grave challenge. The apparent absence of this affliction in our institution appears to be a dividend of the routine use of penicillin for the prophylaxis of ophthalmia neonatorum in all newborns since 1952. Significant confirmation of the efficacy of parenteral penicillin therapy for this purpose derives from a recent report from Halifax in Canada. It is concerned with 983 newborns weighing less than 2,500 gm at birth in whom no deaths occurred during the study period. This contrasted with ten deaths due to GBS disease in 1,208 similar infants in the preceding year when penicillin was not administered.

The present case describes a foot wound caused by a clam shell from which both Vibrio parahaemolyticus and Vibrio vulnificus were recovered. Although extraintestinal infections associated with Vibrio parahaemolyticus have been reported previously, the simultaneous isolation of two marine vibrios from our case suggests that these organisms may coexist in mixed infections from a common source.

“Ah! That accounts for it,” said the Hatter. “He won't stand beating. Now, if you only kept on good terms with him, he'd do almost anything you like with the clock. For instance, suppose it were nine o'clock in the morning, just in time to begin lessons: you'd only have to whisper a hint to Time, and round goes the clock in a twinkling! Half past one, time for dinner!”

A retrospective analysis of serotypes and groups of Streptococcus pneumoniae recovered over a 12-year period (1973-1984) from pediatric and adult patients ( > 18 years old) at a large urban hospital is presented. The majority of the 3,302 pneumococcal isolates (2,807, or 85%) were from the respiratory tract, 68% were from adults, and 30% were from children. Of the respiratory isolates from adults, the most common serotypes and groups recovered were, in decreasing order: 3, 19, 9, 23, 4, and 6; and from children, the most common were: 19, 3, 6, 23, 15, and 18. The remaining 15% (495) of the isolates were from patients with either meningitis and/or bacteremia, with 433 (87%) from adults and 62 (13%) from children. From these body sites, the most common types and groups were 4, 3, 8, 14, 9, and 19 from adults and 14, 6, 18, 19, 23, and 4 from children. Approximately 89% of these types and groups are represented in the 23-valent vaccine. Although other investigators have reported corresponding arrays of isolates represented in the vaccine, the contrasts in serotypes underscore regional differences which may be germane to future vaccine formulations.

A penicillin (PCN) tolerant [minimal inhibitory concentration (MIC) less than or equal to 0.02, minimal bactericidal concentration (MBC) = 3.10 micrograms/ml] group A streptococcus (GAS) was recovered from the bone aspirate of a child with osteomyelitis. The penicillin therapy with 200,000 micron/kg X day, and subsequently ampicillin 360 mg/kg X day, resulting in a serum ampicillin concentration of 74 micrograms/ml, failed to achieve a serum bactericidal effect greater than 1:2. Ninety-nine additional isolates of GAS obtained from 99 infants and children with pharyngitis were randomly selected for study. Organisms were screened for tolerance by macrobroth dilution determination at 0.05 and 1.0 microgram/ml of penicillin. Twenty-two of 100 organisms had MICs = 0.05 microgram/ml and MBCs = 1.0 microgram/ml; further tests were performed on these organisms. Twenty of the 22 strains (20% of all GAS) grown in Mueller-Hinton broth with 2% sheep blood were tolerant to penicillin at 24 hr, with MICs less than or equal to 0.02 and MBCs = 0.39 microgram/ml. When retested at 48 hr the MBCs of the 20 tolerant strains had decreased: three strains by twofold, three strains by fourfold, four strains by eightfold, one strain by 16-fold, and nine strains by 40-fold or greater. Seven strains were not tolerant after 48 hr of incubation. The detection of tolerance was media dependent; only nine strains were tolerant when grown in Todd-Hewitt broth. Tolerance to GAS was more frequent than generally suspected. The phenomenon of tolerance, and potentially delayed killing may alter prophylaxis and therapy of GAS disease and merits further investigation.

Publisher Summary This chapter discusses the detection of bacteriurea by bioluminescence. The criteria for defining significant bacteriurea are dependent on the patient from whom the sample is derived. The conventional criterion invoked to detect urinary tract infections in asymptomatic patients where there is a low prevalence of disease in the population, is 10 4 –10 5 colony-forming units (CFU)/ml in a freshly voided, first morning specimen. The techniques available to determine the presence and quantity of microorganisms in a urine specimen can be divided into those that are growth dependent and those that are non-growth dependent. Growth-dependent methods, by definition, require dilution, inoculation onto a suitable medium, and an incubation period of 18-24 hr. Non-growth-dependent methods, in contrast, do not require cultivation of the organism, but rather provide a direct enumeration of the bacterial population present. As the noncultivation methods provide the user with a quantitation but no identification, they are termed “screening tests.” The development of the firefly luciferin-luciferase system for the assay of adenosine triphosphate (ATP) has had a marked impact on microbiology. Since the amount of ATP within bacterial cells was readily calculated, and the luciferase assay was shown to be sufficiently sensitive to detect the ATP content of as few as 10 CFU/ml, the utility of this method of bacterial quantitation is quickly recognized. Its applicability to clinical material, however, is severely limited by the inability of this method to discriminate between the ATP of microbial origin, and that of host cell origin.

Nosocomial fungal pulmonary infections (Zygomycetes, Aspergillussp.) developed in two premature infants in a special care unit (SCU) adjacent to an area of renovation. Inspection showed that inadequate barriers permitted the passage of airborne particles between the two areas, and cultures confirmed a significantly higher (p≤0.05) density of mold spores in the SCU (0.88 cfu per hour per settling plate) compared to a construction-free comparison area (0.22 cfu per hour per settling plate). The major source of mold was the dust above the hospital's false ceiling. In another construction area, impervious barriers were shown to effectively restrict the dispersal of mold. Our experience addsRhizopustoAspergillusas a possible cause of construction-related nosocomial infection. Sporadic episodes will continue to occur until the hazards of renovation are appreciated and effective preventive measures are routinely instituted.

The Gen-Probe DNA hybridization system, rapid diagnostic assays for the identification of Mycobacterium tuberculosis (MTB) complex and Mycobacterium avium-intracellulare (MAIC) complex, were evaluated. Designed to identify a primary mycobacterial isolate, the former correctly identified 91 of 92 MTB and all 27 non-MTB isolates and controls when compared with conventional identification methods for a sensitivity of 98.91% and specificity of 100%. The latter correctly identified 63 of 64 MAIC isolates and controls and 31 of 32 non-MAIC isolates and controls when compared with conventional identification methods for a sensitivity of 98.43% and a specificity of 96.87%. The one false positive noted with the MAIC probe was an MTB misidentified as an MAIC. The two false negatives noted above were subsequently shown to be contaminated. The tests are fast and easy to perform and interpret.