Identification of contamination sources of Bacillus cereus in pasteurized milk

In order to determine the sources of Bacillus cereus in pasteurized milk, a total of 232 milk samples from various sampling points along milk processing lines and 122 environmental swabs were collected in two dairy plants between March and September, 1996. The incidence of B. cereus vegetative cells in raw milk from the plants was low (< or = 10%). However, the incidence and the average counts of B. cereus spores in the raw milk were very high and similar to those of B. cereus vegetative cells in pasteurized milk or final products after enrichment (> 80% and 1.1 x 10(5) cfu ml(-1), respectively). The incidence and average count of both vegetative cells and spores of B. cereus in environmental swabs was low. Using the microbial identification system (MIDI), a library of B. cereus fatty acid profiles comprising 229 B. cereus isolates from milk samples and environmental swabs was constructed using a critical Euclidian distance of 6.0 units as the cut-off value. Using this library, the relationship between 546 B. cereus isolates from the different sampling points along the milk processing lines and the environmental swabs was determined. Most B. cereus isolates obtained from the pasteurized milk and final products belonged to the same sub-groups as the B. cereus strains germinated from spores in raw milk. Furthermore, specific sub-groups were found in pasteurized milk, different dairy plants and at different sampling times. The results suggested that B. cereus spores in raw milk were the major source of B. cereus in pasteurized milk and that post-pasteurization contamination along the milk processing lines was possibly a minor source of B. cereus in pasteurized milk.     

Recurrence of hemolytic-uremic syndrome in renal transplant recipients: a meta-analysis

To identify contributing factors for cheese-associated outbreaks, we reviewed all cheese-associated outbreaks of human illness reported to the Centers for Disease Control and Prevention (CDC) with onsets during 1973 to 1992. The infrequency of large, cheese-associated outbreaks was notable because such outbreaks had been a frequent public health problem before the mid-20th century. Of 32 reported cheese-associated outbreaks, 11 attributed to manufacturing errors caused most of the illnesses and hospitalizations and all 58 deaths. Important factors in these 11 outbreaks were manufacturing cheese with raw or improperly pasteurized milk and postpasteurization contamination. If current Food and Drug Administration sanitary requirements for cheesemaking had been met, these outbreaks would have been preventable. In two outbreaks of Salmonella infections, fewer than 10 Salmonella per 100 g of cheese were detected. In two outbreaks of Brucella infections, efforts to recover the pathogen from the implicated cheese were unsuccessful, emphasizing the inadequacy of end product testing for assuring consumer safety. Curing cheeses kills most bacteria present in cheeses; however, evidence from sources other than the CDC Foodborne Disease Outbreak Surveillance System suggests that curing alone may not be a sufficient pathogen control step to eliminate Salmonella, Listeria, and E. coli O157:H7 from cheese.     

Interferon-induced protein 10 and interleukin 8. C-X-C chemokines present in proliferative diabetic retinopathy

From May through November 1997, 1,011 samples of raw milk from bulk storage tanks were examined for the presence of verocytotoxin-producing Escherichia coli of serogroup O157 (O157 VTEC) by immunomagnetic separation following selective enrichment. The samples originated from 1,011 different dairy herds located throughout the Netherlands. O157 VTEC was not isolated from any of the milk samples examined. Additionally, survival of O157 VTEC in raw and UHT-sterilized cow's milk at 7 and 15 degrees C was studied, both in the absence and presence of an activated lactoperoxidase-thiocyanate-hydrogen peroxide system (LPS). Results indicated that the O157 VTEC strain tested was able to grow in raw milk at 7 degrees C as well as at 15 degrees C. Naturally occurring amounts of thiocyanate and hydrogen peroxide in the raw milk tested were not sufficient to activate the LPS. Although the LPS exhibited an antimicrobial activity against O157 VTEC in LPS-activated sterilized milk, O157 VTEC populations were not (or not as obviously) reduced in LPS-activated raw milk. Possibly background microflora were more sensitive to the LPS than the O157 VTEC test strain. It was concluded that raw milk contaminated with O157 VTEC will remain a hazard if kept at 7 or 15 degrees C. Effective pasteurization and avoiding postpasteurization contamination are necessary to ensure the safety of milk.     

Down regulation of yeast G protein-coupled receptors

In this research, totally 200 raw milk samples in different areas of Ankara were collected from various dairy plant. The isolated psychotrophic bacteria from the raw milk samples are the species of Pseudomonas spp., Acinetobacter spp., Alcaligenes and Aeromonas. Isolation of Pseudomonas and other gram(-) psychrotrophic bacteria types are determined as P. aeruginosa 11 (5.5%), P. putida 11 (5.5%), P. fluorescens biotype I 10 (5.0%), P. fluorescens biotype II 4 (2.0%), P. fluorescens biotype III 6 (3.0%), P. aurefaciens 2 (1.0%), P. pseudomallei 3 (1.5%), P. cepacia 1 (0.5%), A. calcoaceticus lowffii 5 (2.5%), A. calcoaceticus anitratum 4 (2.0%), A. faecalis 3 (1.5%) and A. hydrophilia 1 (0.5%).     

Is gastrin trophic? Gastrin/ gastrin receptor "knockout" mice confirm the old hypothesis

Cerumen is the product of the secretion of the sebaceous, ceruminous or apocrine glands together with cells exfoliated from the cornified stratum of the epithelium of the external auditory canal (EAC). In the present study we identified and quantified common flora of human cerumen. The mean count obtained was 10(6) microorganisms per ml of cerumen suspension. In 24 pools of cerumen (33.3 per cent) the isolates were monomicrobial, Staphylococcus epidermidis (12), Corynebacterium spp (10), Staphylococcus aureus (1) and Streptococcus saprophyticum (1). In 48 pools (66.6 per cent) we found polymicrobial isolates. The most commonly isolated bacteria in these polymicrobial isolates were S. epidermidis (35) and Corynebacterium spp. (43). It is noteworthy that there were isolates of Candida albicans in three cases; in one case of Pseudomonas stutzeri, in one case of Pseudomonas aeruginosa, and, on seven occasions, of S. aureus. The organisms isolated as common bacterial components of human cerumen in our experience were similar to those found by other authors. However, the mean count was much higher. This could be related to climatic conditions and to the length of time the cerumen had remained in the external auditory canal.     

Prevention of Listeria monocytogenes contamination on dairy farms and in the cheese industry

Listeria monocytogenes remains a pathogen bacteria the prevention of which, in food products, stays delicate. A complete organization, from the farmer's production to the industry and the consumer is necessary to eliminate Listeria in a type of food product. Listeria monocytogenes is susceptible of contaminate raw milk. The silage may be a major source of the occurrence of Listeria monocytogenes in raw milk. In this case, the contamination sources in a dairy farm and the good hygienic practices must be well-defined. In dairy industry, the contamination must be managed by the application of a systematic and methodically system like H.A.C.C.P. (Hazard Analysis Critical Control Points). It is useful for the study of Listeria monocytogenes contamination and involve the hazard analysis of each industry plant. In fact, the raw products, food products, manufacturing process, environmental conditions, process equipment, materials and staff organizational are specific and characteristic.     

Staff education in the Instituto de Medicina Tropical "Pedro Kourí". Yesterday, today and tomorrow (1979-1993)

A raw milk bacterial isolate, identified as Yersinia kristensenii was found to produce a bacteriocin which was inhibitory to Yersinia enterocolitica but not to other selected species of Yersinia or Gram-negative bacteria. Maximum production of bacteriocin was obtained when the organism was grown in shake culture at 28 degrees C. Mitomycin C at a concentration of 0.5 micrograms ml-1 induced bacteriocin production. The bacteriocin was partially purified and characterized by ammonium sulphate fractionation and gel filtration. The bacteriocin was completely inactivated when treated with proteolytic enzymes (trypsin and chymotrypsin). Bacteriocin activity was heat-resistant and it retained some of its activity after 5 min at boiling temperature. A total of 15 bacteriocin sensitive-suspected food isolates were further identified biochemically as Yersinia enterocolitica and a non-sensitive isolate was identified as Yersinia intermedia.     

Contamination of beef carcasses by psychrotrophic Pseudomonas and Enterobacteriaceae at different stages along the processing line

The extent of the contamination of beef carcasses with psychrotrophic Pseudomonas spp. and Enterobacteriaceae during slaughter, chilling and cutting was estimated by introducing a new analytical procedure; the contamination index. Comparisons were made between the initial viable counts and the contamination index. The contamination index was calculated as the sum of the bacterial counts obtained during aerobic cold storage of excised meat samples. The presence and composition of spoilage bacteria in the slaughter environment and on the carcasses was also determined at one plant. Rapid chilling was identified as a critical processing step by the contamination index. In addition to this, the dehiding and the chilling in cold storage rooms were implicated as critical operations, with respect to aerosol contamination and surface cross-contamination. Comparison of the composition of spoilage bacteria in the slaughter environment and the bacteria proliferating on the carcass surface samples taken at the corresponding steps showed similar distributions of the identified Pseudomonas spp. In five surveys at two plants, the contamination of beef carcasses along the processing line was estimated. Statistically significant variations between different processing steps were more pronounced for the contamination index than for the conventional counts. It was concluded that the contamination index could be used for identifying critical processing steps, with respect to the extent of contamination of carcasses by psychrotrophic spoilage bacteria.     

Effect of psychrotrophic microorganisms on the plasmin system in milk

The psychrotrophic bacteria that are present in raw milk produce heat-stable proteases that affect the plasmin system and, in turn, the quality of the processed milk and other dairy products. Three bacterial strains, Pseudomonas spp. SRM21A and SRM28A and Pseudomonas fluorescens M3/6, were inoculated at a level of approximately 10(3) cfu/ml into reconstituted nonfat dry milk and incubated at 4 degrees C for up to 9 d. From each sample, casein and whey fractions were obtained and electrophoresed to visualize protein hydrolysis and plasmin activity. Colorimetric assays were used to quantify plasmin-related activities. The casein SDS-PAGE gels showed that, by 5 d of incubation, caseinolytic activity was visible in whey fractions of all three strains at the same molecular mass range as commercial bovine plasmin, which was used as a control. Colorimetric assays indicated that plasmin activity in the casein samples decreased as incubation time increased; plasmin activity in the whey samples increased, peaking at 5 to 7 d. Plasminogen activity decreased over time in the casein fraction and increased in the whey fraction. Protein immunodetection indicated crossreactivity between anti-bovine plasminogen and the plasmin and plasminogen from whey samples collected at 5 and 7 d from the incubated milk. The growth of the Pseudomonas strains tested and their concomitant production of proteases caused the release of plasmin and plasminogen from the casein micelle into the whey fraction.     

Bacterial pathogens and their antimicrobial susceptibility in Kumasi, Ghana

Between January, 1994 and June, 1996 a survey of bacterial isolates from clinical specimens and their antimicrobial susceptibility was performed at the Komfo Anokye Teaching Hospital, Microbiology Department, Kumasi, Ghana. A total of 11,380 bacterial isolates were cultured from eight different specimens. The sites of origin were wounds 32.2%, urine 28.1%, ear, nose and throat 3.6%, sputum 2.5% and aspirates 2.5%. Gram-negative bacteria accounted for 7955 (69.9%) isolates, the main species were Escherichia coli 47.1%, Pseudomonas spp. 16.8%, Proteus spp 14.6%, Klebsiella spp 10.2%, Neisseria gonorrhoeae 4.2%, Gram-positive bacteria contributed 3425 ((30.1%) of isolates, with Staphylococcus aureus 54.6% being the most predominant followed by Coagulase negative Staphylococcus 18.1%, Streptococcus pneumoniae 13.7% and Beta-haemolytic streptococci 4.1%. Escherichia coli showed 88% and 82% resistance to ampicillin and cotrimoxazole respectively with 78% being susceptible to gentamicin. Cefuroxime resistance in Gram-negative bacilli was 5%. As much as 30.6% and 21.7% of Streptococcus pneumoniae isolates were resistant to Penicillin and chloramphenicol respectively. Ten per cent of Staphylococcus aureus strains were susceptible to penicillin and 18% were resistant to flucloxacillin.     

Aerobic and anaerobic microbiology of axillary hidradenitis suppurativa

A retrospective review of the microbiological and clinical data of 17 specimens obtained from axillary hidradenitis suppurativa (HS) over a period of 6 years was undertaken to study the aerobic and anaerobic microbiology of this condition. A total of 42 bacterial isolates (2.5 per specimen) were obtained, 12 aerobic or facultative (0.7 per specimen) and 30 anaerobic or micro-aerophilic (1.8 per specimen). Aerobic and facultative bacteria only were isolated in six (35%) cases, anaerobic bacteria only in seven (41%) and mixed aerobic and anaerobic bacteria in four (24%). The predominant aerobic bacteria were Staphylococcus aureus (six isolates), Streptococcus pyogenes (three) and Pseudomonas aeruginosa (two). The most frequently isolated anaerobes were Peptostreptococcus spp. (10), Prevotella spp. (seven), micro-aerophilic streptococci (four), Fusobacterium spp. (three) and Bacteroides spp. sensu stricto (three). This study highlights the polymicrobial nature and predominance of anaerobic bacteria in axillary HS and the need for antimicrobial thereby to reflect this.     

Bacterial infection and endotoxin in female reproductive tract in rats: correlation with the developmental status of preimplantation embryos

During mammalian preimplantation development, a substantial numbers of embryos are believed to be lost for reasons that are unclear. Using female rats, we investigated whether the developmental status of embryos is influenced by bacterial infection and endotoxin in the reproductive tract. From the vagina of cycling rats (n = 11), 21 bacterial isolates were identified; they were Streptococcus faecalis (S. faecalis; 38%), Escherichia coli (E. coli; 19%), Acinetobactor calcoaceticus (A. calcoaceticus; 14%), and coagulase negative staphylococcus (14%), Micrococcus sp. (5%), Bacillus subtilis (B. subtilis; 5%) and Proteus vulgaris (P. vulgaris; 5%). From the vagina of day 4 pregnant rats (n = 12), 26 isolates were identified; they were S. faecalis (23%), A. calcoaceticus (23%), E. coli (15%), Micrococcus sp. (15%), B. subtilis (8%), P. vulgaris (4%), Staphylococcus aureus (4%), beta-hemolytic streptococcus (4%) and Pseudomonas aeruginosa (4%). Gram negative bacteria found in the vagina of cycling and day 4 pregnant rats were 38% and 46%, respectively. In both, bacterial load was 10(3)-10(5) colony forming units and there was no association with the abnormality of the recovered embryos. However, in two day 4 pregnant animals, pathogenic bacteria (Staphylococcus aureus and beta-hemolytic streptococcus) were isolated and embryos recovered from them were degenerated and deformed. The vagina of day 9 pregnant animals (n = 7) were, however, sterile. Consistently, in all animals, the upper reproductive tract (uterus and oviduct) was devoid of any bacteria and no anaerobic bacteria were isolated from any part of the tract. The levels of endotoxin in the vagina of cycling and day 4 pregnant rats were 1.35 +/- 0.1 and 1.17 +/- 0.1 endotoxin units (EU), respectively. It was undetectable in the oviduct and uterus of all animals (n = 5) except one which showed high levels of endotoxin in uterus (4.5 EU) and oviduct (2.2 EU) and the animal also produced degenerated and deformed embryos. These results indicate that common bacterial flora of vagina may not affect embryo development and the presence of pathogenic bacteria in the vagina and/or endotoxin in reproductive tract could be detrimental to viability of gametes and preimplantation embryos in rats.     

Quantitative risk assessment of human listeriosis from consumption of soft cheese made from raw milk

Microbial hazards have been identified in soft cheese made from raw milk. Quantification of the resulting risk for public health was attempted within the frame of the Codex Alimentarius Commission, 1995 approach to quantitative risk assessment, using Monte Carlo simulation software. Quantitative data could only be found for Listeria monocytogenes. The complete process of cheese making was modeled, from milking to consumption. Using data published on the different sources of milk contamination (environment and mastitis) and bacterial growth, distributions were assumed for parameters of the model. Equations of Farber, J.M., Ross, W.H., Harwing, J. (1996) for general and at-risk populations were used to link the ingested dose of L. monocytogenes to the occurrence of listeriosis. The probability of milk contamination was estimated to be 67% with concentration ranging from 0 to 33 CFU ml-1. The percentage of cheese with a predicted concentration of L. monocytogenes greater than 100 CFU g-1 was low (1.4%). The probability of consuming a contaminated cheese serving was 65.3%. Individual annual cumulative risk of listeriosis, in a population each consuming 50 servings of 31 g, ranged from 1.97 x 10(-9) to 6.4 x 10(-8) in a low-risk sub-population and 1.04 10(-6) to 7.19 10(-5) in a high-risk sub-population. The average number of expected cases of listeriosis per year was 57 for a high-risk sub-population and one for a low-risk healthy sub-population. When the frequency of environmental milk contamination was reduced in the model and L. monocytogenes mastitis was eliminated, the expected incidence of listeriosis decreased substantially; the average number of expected cases was reduced by a factor of 5. Thus the usefulness of simulation to demonstrate the efficiency of various management options could be demonstrated, even if results should be interpreted with care (as many assumptions had to be made on data and their distributions.     

Organisms isolated from dogs and cats with anaerobic infections and susceptibility to selected antimicrobial agents

OBJECTIVE: To determine the prevalence of obligate anaerobic bacteria in bacterial infections in dogs and cats and susceptibility to selected antimicrobial agents. DESIGN: Case series. SAMPLE POPULATION: Specimens from 1,267 dogs and 243 cats. PROCEDURE: Standard anaerobic and aerobic bacterial culture methods were used. Anaerobic isolates were tested for susceptibility to selected antimicrobial agents. RESULTS: Obligate anaerobic bacteria were isolated from 199 (15.7%) and 69 (28.4%) specimens obtained from dogs and cats, respectively. More than half of the specimens that contained obligate anaerobic bacteria were from draining tracts (exclusively dogs), pleural fluid, abscesses, bones, the respiratory tract, or the abdominal cavity. The most commonly isolated obligate anaerobic bacteria (approx 70% of all isolates) were Bacteroides spp, Peptostreptococcus spp, Fusobacterium spp, and Porphyromonas spp. Eighty percent of the specimens that contained obligate anaerobic bacteria also contained facultative anaerobic or aerobic organisms. The organisms most commonly isolated in association with obligate anaerobic bacteria were members of the family Enterobacteriaceae (Escherichia coli was the most common), Pasteurella spp, and Staphylococcus intermedius. Ninety-seven obligate anaerobic isolates were tested for susceptibility to ampicillin, amoxicillin-clavulanic acid, chloramphenicol, clindamycin, and metronidazole. All were susceptible to amoxicillin-clavulanic acid and chloramphenicol, and most were susceptible to metronidazole. Only 71% of the Bacteroides isolates were susceptible to ampicillin, and only 83% were susceptible to clindamycin. Only 80% of the Clostridium isolates were susceptible to clindamycin, but all were susceptible to ampicillin. CLINICAL IMPLICATIONS: Data on sites and conditions from which anaerobic bacteria are commonly isolated, along with results of susceptibility testing, may be useful in designing antimicrobial treatment regimens.     

Synthesis of novel cyclic protease inhibitors using Grubbs olefin metathesis

The microbiologic features of infected sinus aspirates in nine children with neurologic impairment were studied. Anaerobic bacteria, always mixed with aerobic and facultative bacteria, were isolated in 6 (67%) aspirates and aerobic bacteria only in 3 (33%). There were 24 bacterial isolates, 12 aerobic or facultative and 12 anaerobic. The predominant aerobic isolates were Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus (2 each) and Proteus mirabilis, Pseudomonas aeruginosa, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae (1 each). The predominant anaerobes were Prevotella sp. (5), Peptostreptococcus sp. (4), Fusobacterium nucleatum (2), and Bacteroides fragilis (1). Beta-lactamase-producing bacteria were isolated from 8 (89%) patients. Organisms similar to those recovered from the sinuses were also isolated from tracheostomy site and gastrostomy wound aspirates in five of seven instances. This study demonstrates the uniqueness of the microbiologic features of sinusitis in neurologically impaired children, in which, in addition to the organisms known to cause infection in children without neurologic impairment, facultative and anaerobic gram-negative organisms that can colonize other body sites are predominant.     

Isolation of aerobic microbes from Ixodes scapularis (Acari: Ixodidae), the vector of Lyme disease in the eastern United States

The spirochete Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Benner is transmitted by Ixodes scapularis Say, a vector of Lyme disease. As a 1st step into investigating the possibility of biocontrol of the tick, we identified the microbiota associated with the ticks. We collected, identified, and determined the sex of ticks from foliage and deer. Seventy-three initial bacterial isolates were recovered from 43 ticks (27 adults and 16 nymphs). The bacteria isolated from nymphs were qualitatively different (mainly gram-negative cocci) from the bacteria isolated from adult ticks (gram-negative and gram-positive rods). To determine long-term viability, these isolates were stored for 6 mo under laboratory conditions. After storage, 63 surviving bacterial isolates were characterized using the Biology System of identification by substrate utilization. Forty-four isolates were identified to the species level. Our characterization efforts focused on the 40 spore-forming bacteria, which could prove useful in the biocontrol of ticks. Eleven species of Bacillus were identified. Bacillus thuringiensis-B. cereus was the predominant species group isolated. Six isolates from this group formed crystals.     

Numerical taxonomy and ecology of petroleum-degrading bacteria

A total of 99 strains of petroleum-degrading bacteria isolated from Chesapeake Bay water and sediment were identified by using numerical taxonomy procedures. The isolates, together with 33 reference cultures, were examined for 48 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using both the simple matching and the Jaccard coefficients. Clustering was achieved by the unweighted average linkage method. From the sorted similarity matrix and dendrogram, 14 phenetic groups, comprising 85 of the petroleum-degrading bacteria, were defined at the 80 to 85% similarity level. These groups were identified as actinomycetes (mycelial forms, four clusters), coryneforms, Enterobacteriaceae, Klebsiella aerogenes, Micrococcus spp. (two clusters), Nocardia species (two clusters), Pseudomonas spp. (two clusters), and Sphaerotilus natans. It is concluded that the degradation of petroleum is accomplished by a diverse range of bacterial taxa, some of which were isolated only at given sampling stations and, more specifically, from sediment collected at a given station.     

Bacterial Transport in Gas-Sparged Porous Medium

To improve the feasibility of soil-aquifer remediation using bioaugmentation, more efficient methods are needed to widely disperse pollutant-degrading bacteria in porous media. Under water-saturated conditions, bacteria readily adhere to soil particles, but under unsaturated conditions, bacteria preferentially accumulate at the air-water interface. Air sparging a saturated porous medium produces a mobile water interface that was hypothesized to facilitate bacterial transport. To investigate whether gas sparging increased bacterial transport relative to saturated-water conditions, the transport of three strains of bacteria and negatively charged microspheres of different relative hydrophobicities RH was measured in saturated and gas-sparged quartz-packed columns. Gas sparging increased (>60%) the bacterial transport in only one case (Pseudomonas fluorescens P17; RH = 27%). Transport of the other two strains were either unaffected by gas sparging (Mycobacterium vaccae JOB5; RH = 33%), or was reduced (Pseudomonas aeruginosa; RH = 75%) relative to water-saturated conditions. Microspheres were the most hydrophobic (RH = 98%) and the most retained of all particles under saturated conditions, but microsphere transport was unaffected by gas sparging. These preliminary results suggest that the effect of gas sparging on colloid transport is particle specific and not predictable from measurement of relative hydrophobicity.     

The diversity of lipases from psychrotrophic strains of Pseudomonas: a novel lipase from a highly lipolytic strain of Pseudomonas fluorescens

Strains of Pseudomonas fluorescens and Ps. fragi are the predominant psychrotrophs found in raw milk and may cause spoilage due to the secretion of hydrolytic enzymes such as lipase and protease. The diversity of lipases has been examined in Pseudomonas isolates from raw milk which represent different taxonomic groups (phenons). Significant diversity was found using both DNA hybridization and immunoblotting techniques, which has implications for the development of a diagnostic test. The lipase-encoding gene (lipA) was cloned from one strain, C9, of Ps. fluorescens biovar V. In contrast to previously reported lipase sequences from Ps. fluorescens, the gene encodes a lipase of M(r) 33 kDa. Alignment of all known Pseudomonas and Burkholderia lipase amino acid sequences indicates the existence of two major groups, one of M(r) approximately 30 kDa comprising sequences from Ps. fragi, Ps. aeruginosa, Ps. fluorescens C9 and Burkholderia, and one of approximately 50 kDa comprising Ps. fluorescens lipases. The lipase from C9 does not contain a signal peptide and is presumed to be secreted via a signal peptide-independent pathway. The lipA gene of strain C9 was disrupted by insertional mutagenesis. The mutant retained its lipolytic phenotype, strongly suggesting the presence of a second lipase in this strain.     

Risk factors associated with uterine cervical cancer in Korea: a case-control study with special reference to sexual behavior

We have obtained sediment samples from the world's deepest sea-bottom, the Mariana Trench challenger point at a depth of 10,898 m, using the new unmanned submersible Kaiko. DNA was extracted from the sediment, and DNA fragments encoding several prokaryotic ribosomal RNA small-subunit sequences and pressure-regulated gene clusters, typically identified in deep-sea adapted bacteria, were amplified by the polymerase chain reaction. From the sequencing results, at least two kinds of bacterial 16S rRNAs closely related to those of the genus Pseudomonas and deep-sea adapted marine bacteria, and archaeal 16S rRNAs related to that of a planktonic marine archaeon were identified. The sequences of the amplified pressure-regulated clusters were more similar to those of deep-sea barophilic bacteria than those of barotolerant bacteria. These results suggest that deep-sea adapted barophilic bacteria, planktonic marine archaea, and some of the world's most widespread bacteria (the genus Pseudomonas) coexist on the world's deepest sea-bottom.