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Laser Powder Bed Fusion (LPBF), is used to produce a component in layers by selective re-melting of a metal powder bed. A powder layer of an alloy is applied to a metal substrate within a process chamber filled with an inert gas. This powder layer is locally heated by a laser to a temperature above the melting point of the used alloy. Only regions of the applied powder which belong to the desired component are treated by the laser beam. After heating the layer is complete, the build platform is lowered by 30–90 µm and a new powder layer is applied. The procedure is repeated until the part is completed. After suitable post processing the part can be used. The relative density of the finished component is close to 100%. Depending on the deposition system the laser spot diameter measures approximately 40–80 µm, therefore the size of the resulting melt region is relatively small while cooling rates and temperature gradients are very high. Hence some resulting material properties of certain laser-melted alloys differ from the properties which can be achieved by conventional production routes. Furthermore, studies show that adjustment of certain process parameters can be used to influence the material condition, e.g., the anisotropy of the mechanical material properties. On the one hand this degree of freedom might offer opportunities to realize designed component properties, but on the other hand the modeling of the material condition and the resulting mechanical properties is challenging. A testing program covering different stress states as well as different material orientations has been performed at COMTES FHT. The tests revealed a significant orthotropy of plasticity and fracture which both are considered in the derived material card for the material model MF GenYld+CrachFEM – a material model developed by MATFEM. A good agreement between physical tests and finite element simulations of the performed tests was found. Chances and challenges in using the full potential of AM deposited materials based on detailed numerical modeling considering material orthotropic behavior are presented here for Inconel 718 and are supported by experimental testing.

ABSTRACTSalmonellaisolates have traditionally been classified by serotyping, the serologic identification of two surface antigens, O-polysaccharide and flagellin protein. Serotyping has been of great value in understanding the epidemiology of Salmonellaand investigating disease outbreaks; however, production and quality control of the hundreds of antisera required for serotyping is difficult and time-consuming. To circumvent the problems associated with antiserum production, we began the development of a system for determination of serotype in Salmonellabased on DNA markers. To identify flagellar antigen-specific sequences, we sequenced 280 alleles of the three genes that are known to encode flagellin in Salmonella, fliC, fljB, and flpA, representing 67 flagellar antigen types. Analysis of the data indicated that the sequences from fliC, fljB, and flpAclustered by the antigen(s) they encode not by locus. The sequences grouped into four clusters based on their conserved regions. Three of the four clusters included multiple flagellar antigen types and were designated the G complex, the Z4 complex, and the a cluster. The fourth cluster contained a single antigen type, H:z29. The amino acid sequences of the conserved regions within each cluster have greater than 95% amino acid identity, whereas the conserved regions differ substantially between clusters (75 to 85% identity). Substantial sequence heterogeneity existed between alleles encoding different flagellar antigens while alleles encoding the same flagellar antigen were homologous, suggesting that flagellin genes may be useful targets for the molecular determination of flagellar antigen type.

In 1995, Salmonella Enteritidis (SE) cases in the state of Utah increased fivefold. Isolates were identified as phage type 4 (PT4). Risk factors and sources of infection were investigated in two case-control studies, a traceback of implicated foods, and environmental testing. Forty-three patients with sporadic infections and 86 controls were included in a case-control study of risk factors for infection. A follow-up case-control study of 25 case and 19 control restaurants patronized by case and control patients examined risks associated with restaurant practices. In the first case-control study, restaurant dining was associated with illness (P = 0·002). In the follow-up case-control study, case restaurants were likelier to use > 2000 eggs per week (P < 0·02), to pool eggs (P < 0·05), and to use eggs from cooperative ‘A’ (P < 0·009). Eggs implicated in separately investigated SE PT4 outbreaks were traced to cooperative ‘A’, and SE PT4 was cultured from one of the cooperative's five local farms. We conclude that SE PT4 transmitted by infected eggs from a single farm caused a fivefold increase in human infections in Utah.

Standardization of test methods does not always result in the ability to duplicate data in various laboratories. The author describes the efforts made to reduce variability among a group of laboratories for an apparently simple test. A considerable effort and expenditure of money did not produce the desired result. The author concluded that the variability arises from differences in operator handling of samples which are not describable or recognized. He suggests that the solution may be in establishing a training course for all technicians or by the development of standard samples and the use of correction factors for each laboratory to adjust their results to that of the industry average.

The name Providencia rustigianii sp. nov. is proposed for a group of organisms previously known as Providencia alcalifaciens biogroup 3. By DNA hybridization, strains of P. rustigianii were 81 to 99% related to each other at 60 degrees C, but only 44 to 49% related to P. alcalifaciens biogroups 1 and 2 and 26 to 33% related to Providencia stuartii. P. rustigianii could be differentiated from P. alcalifaciens and P. stuartii by simple biochemical tests. P. rustigianii produced acid from D-galactose but not from trehalose; P. stuartii produced acid from both; and P. alcalifaciens produced acid from neither. P. rustigianii could be distinguished from Providencia rettgeri (formerly Proteus rettgeri) by urea hydrolysis and acid production from D-arabitol; P. rustigianii was negative for these two tests, but P. rettgeri was positive. Strains of P. rustiganii were 32 to 34% related to strains of P. rettgeri. Three of the 11 strains of P. rustigianii were isolated from stools, but the sources of the other isolates are unknown. Three strains (27%) were sensitive to colistin, and 82 to 100% were sensitive to ampicillin, carbenicillin, cephalothin, gentamicin, kanamycin, nalidixic acid, streptomycin, and tetracycline. Strain ATCC 33673 (CDC no. 0132-68) is the type strain for this species.

The number of reported isolates of Salmonella enteritidis has increased dramatically in the last 10 years. For many years phage typing has been a useful epidemiologic tool for studying outbreaks of S. typhi and S. typhimurium. In 1987, Ward et al. (L. R. Ward, J. De Sa, and B. Rowe, Epidemiol. Infect. 99:291-294, 1987) described a phage typing scheme for S. enteritidis. This system differentiated 27 phage types by use of 10 typing phages. With these phages, we typed 573 strains of S. enteritidis from humans (42 outbreaks), animals, food, and the environment. Ninety-six percent of the strains were typeable. The most common phage types were 8 (48.2%), 13a (20.1%), 13 (7.8%), and 14b (7.8%). Most of the strains were specifically collected from egg-related outbreaks in the northeastern United States in 1988 and 1989, probably accounting for the distribution of the four most common types in this sample. This system was particularly useful for differentiating a group of animal strains that had a number of diverse phage types. For 49 animal strains typed, 16 different patterns were obtained. Phage type 8 represented 32% of these strains, but no other phage type represented more than 8% of these strains. One-half of the 16 animal strains that were phage type 8 were from poultry. This phage typing system will be useful for comparing phage types found in the United States with those types encountered worldwide and for determining whether virulent strains of phage type 4 are entering the United States. Additional phage typing systems as well as molecular techniques are being studied to determine whether they can differentiate strains of phage types 8 and 13a.

To evaluate the laboratory techniques for subtyping isolates of Salmonella enteritidis, we compared the plasmid profiles (PP), phage types (PT), and antimicrobial susceptibility patterns (AS) of two nationally representative samples of sporadic human S. enteritidis isolates from 1979 (n = 28) and 1984 (n = 37), 43 isolates from 20 outbreaks of S. enteritidis infections between 1983 and 1987, and 46 animal isolates selected from the U.S. Department of Agriculture Veterinary Services Laboratory in 1986 and 1987. Sporadic and outbreak isolates from humans showed similar rates of resistance to at least one of a panel of antimicrobial drugs (23 and 14%, respectively), PT (91 and 98%, respectively), and PP (97 and 100%, respectively). Sixteen different PP were identified in sporadic, outbreak, and animal isolates; two PP accounted for 76% of sporadic and outbreak isolates. Sporadic human isolates were of PT 8 (42%), of PT 13a (37%), nontypeable (9%), of PT 14b (8%), of PT 9a (3%), and of PT 13 (2%). Outbreak human isolates had similar distributions of PT. PT 8 was associated with poultry: 58% (7 of 12) of the poultry isolates but only 24% (8 of 34) of the isolates from other animals were of PT 8 (P less than 0.04). Although antimicrobial susceptibility patterns do not appear as useful as an epidemiologic marker, PP and PT effectively subtyped S. enteritidis.

The name Moellerella wisconsensis is proposed for a group of the family Enterobacteriaceae previously called enteric group 46. The species name, wisconsensis, was coined because six of the nine strains were isolated in Wisconsin. M. wisconsensis strains were negative for indole production, Voges-Proskauer, H2S production, urea, phenylalanine deaminase, lysine and ornithine decarboxylases, arginine dihydrolase, gas production from D-glucose, acid production from trehalose, and motility; the strains were positive for methyl red, citrate (Simmons), and acid production from lactose and raffinose and resistant to colistin. DNAs from five strains of M. wisconsensis were highly related (80 to 93% in reactions assayed on hydroxyapatite at 60 degrees C and 78 to 97% at 75 degrees C) to 32P-labeled DNA of the proposed type strain (CDC 2896-78, ATCC 35017). Labeled DNA from this type strain was only 2 to 32% related (at 60 degrees C) to DNA from 49 strains of named and unnamed species of Enterobacteriaceae. Eight of nine M. wisconsensis strains were isolated from human stool samples. Clinical information on one strain was available, and it was found to be associated with a case of diarrhea. On MacConkey agar, colonies of M. wisconsensis were bright red with precipitated bile around them and thus were indistinguishable from Escherichia coli colonies. Future studies should focus on the isolation of this new organism and its relationship to human disease.

We compared the phage types, antimicrobial resistance patterns, and plasmid profiles of 20 groups of isolates received at the Centers for Disease Control from Salmonella typhimurium outbreaks between 1975 and 1982 to determine the most useful laboratory method for identifying epidemiologically related isolates of S. typhimurium. In 18 (90%) of the 20 outbreaks, epidemiologically related isolates were identified as being the same by each of the three methods. In a subgroup of nine outbreaks in which isolates unrelated to the outbreak were submitted for comparison, outbreak isolates were differentiated from such control isolates six times (67%) by phage typing alone, four times (44%) by antimicrobial susceptibility testing alone, and eight times (89%) by plasmid profile analysis alone. Epidemic isolates were multiply susceptible, nontypable, or without plasmids in 14 (70%), 1 (5%), and 3 (15%), respectively, of the 20 outbreaks. Plasmid analysis appeared to be at least as specific as phage typing in identifying epidemiologically related isolates of S. typhimurium as being the same or in differentiating them from control specimens; both techniques appeared to be superior to antimicrobial susceptibility testing.

Strains formerly classified as the aerogenic (gas-producing) biogroup of Vibrio fluvialis were shown by DNA relatedness to be a separate species. The species was named Vibrio furnissii sp. nov. (type strain ATCC 35016 = CDC B3215). Three strains of V. furnissii were 79% or more related to the type strain of V. furnissii and about 50% related to the type strain of V. fluvialis. V. fluvialis strains were 40 to 64% related to the type strain of V. furnissii. Divergence in related sequences was only 0.0 to 1.5% among strains of V. furnissii and among strains of V. fluvialis but was 5.0 to 8.0% in interspecific reactions between V. fluvialis and V. furnissii. V. furnissii was aerogenic (produced gas from the fermentation of carbohydrates), whereas V. fluvialis was anaerogenic (did not produce gas from the fermentation of carbohydrates). Another test of some help in differentiating the two species was fermentation of L-rhamnose (57% positive for V. furnissii and negative for V. fluvialis). In addition to the reactions above, V. furnissii is distinguished from other salt-requiring vibrios on the basis of its positive reactions in tests for Møller L-arginine, L-arabinose, maltose, and D-mannitol and its negative reactions for Møller L-lysine and L-ornithine, lactose, and Voges-Proskauer. V. furnissii has been isolated from patients with acute gastroenteritis in at least two outbreaks of food poisoning; its role as a cause of diarrhea needs further study.

Vibrio metschnikovii and Vibrio gazogenes are two new Vibrio species that have been little studied. Thirteen strains of V. metschnikovii were highly related to the type strain, NCTC 8443, by DNA-DNA hybridization. Relatedness values were 83 to 90% at 60 degrees C and 75 to 84% at the more stringent 75 degrees C. Divergence values ranged from 0.7 to 1.9. Strains of V. metschnikovii were oxidase negative and did not reduce nitrate to nitrite. The other phenotypic characteristics agreed with published data. Twenty-three strains of V. gazogenes were isolated from salt marshes and marshy areas on the coast of North and South Carolina. A new medium, marine agar supplemented with an additional 2.5% agar, reduced the problem of swarming by marine Vibrio species and enhanced the isolation of V. gazogenes and other organisms. By DNA-DNA hybridization, 22 of 23 strains were 76% or more related to the type strain of V. gazogenes, ATCC 29988. However, four DNA hybridization subgroups were defined on the basis of divergence values and/or phenotype. Strains of DNA group 1 were more highly related to each other, and this group contained the type strain and six other strains. Strains of DNA group 2 were more highly related to each other, and this group contained reference strain ATCC 43942 and 14 other strains. Strains of DNA group 1 did not ferment melibiose or D-sorbitol (one strain was sorbitol positive), but strains of DNA group 2 fermented both sugars. A revised phenotypic description of V. gazogenes based on 24 strains was written on the basis of reactions (within 2 days of incubation) at 25 degrees C in media supplemented with Na+, K+, and Mg2+. Positive results (100% positive unless indicated) included motility; gas production during fermentation (96% at 2 days, 100% at 3 to 7 days); growth in nutrient broth with the addition of 1% NaCl (88%), 2% NaCl, 3.5% NaCl, 6% NaCl, 8% NaCl, and 10% NaCl (92%); dry red or orange colonies on marine agar; and fermentation of L-arabinose, cellobiose, D-galactose (88%), D-glucose, lactose (88%), maltose, D-mannitol (96%), D-mannose, salicin, sucrose, trehalose, and D-xylose. Negative results included oxidase; nitrate reduction to nitrite (4% positive); indole production; lysine decarboxylase; ornithine decarboxylase; arginine dihydrolase; swarming; growth on TCBS agar; growth in nutrient broth with 0% NaCl, 0.1% NaCl, 0.2% NaCl, 0.3% NaCl, and 0.4% NaCl (8% positive); and fermentation of adonitol, D-arabitol, dulcitol, erythritol, D-galacturonate, i-inositol, alpha-methyl-D-glucoside, raffinose, and L-rhamnose. Variable results were found for the Voges-Proskauer reaction (62% positive), growth in nutrient broth plus 0.5% NaCl (29%) and 12% NaCL (42%), and fermentation of melibiose (71%) and D-sorbitol (71%).

In 1983 the vernacular name Enteric Group 501 was coined for a group of strains that had been referred to our laboratory as "possible Vibrio damsela that does not require NaCl for growth." By DNA-DNA hybridization (hydroxyapatite method, 32P, 60 and 75 degrees C), six strains of Enteric Group 501 were closely related to the labeled strain 2446-81 (70 to 95% at 60 degrees C and 71 to 93% at 75 degrees C; 0 to 1% divergence). Type strains of all Aeromonas species and reference strains of six other Aeromonas DNA hybridization groups were 26 to 42% related (60 degrees C) to strain 2446-81, but type strains of 27 Vibrio and Photobacterium species, including V. damsela, were 0 to 1% (75 degrees C) related. We propose the name Aeromonas schubertii for the highly related group of seven strains formerly known as Enteric Group 501. The type strain is designated as ATCC 43700 (CDC 2446-81). Strains of A. schubertii grew well at 36 degrees C and had positive reactions at this temperature for methyl red, Voges-Proskauer (1% NaCl, Coblentz method), lysine decarboxylase, arginine dihydrolase, motility, lipase, DNase, nitrate reduction to nitrite, oxidase, and growth in nutrient broth with 0 and 1% NaCl. There was no growth in 6% NaCl or on thiosulfate-citrate-bile salts-sucrose agar. The following sugars were fermented: D-glucose, D-galactose, maltose, D-mannose, and trehalose. The following sugars were not fermented: adonitol, L-arabinose, D-arabitol, cellobiose, dulcitol, erythritol, myo-inositol, lactose, D-mannitol, melibiose, alpha-CH3-D-glucoside, raffinose, L-rhamnose, salicin, D-sorbitol, sucrose, and D-xylose. Esculin was not hydrolyzed, and the string test was negative. The mannitol-negative reaction differtiates A. schubertii from other Aeromonas species. The antibiogram of this organism is typical of other Aeromonas strains (resistance to ampicillin and carbenicillin and susceptibility to most other agents). A. schubertii strains have been isolated from abscesses (two strains), wound (one), skin (one), pleural fluid (one), and blood (two). The two blood isolates suggest clinical significance typical of other Aeromonas species , but further information is needed on this group.

In 1983, the vernacular name Enteric Group 77 was coined for a group of strains that had been referred to our laboratory as "possible Vibrio cholerae except for gas production." By DNA-DNA hybridization (hydroxyapatite, 32P), 8 of 10 strains of Enteric Group 77 were very highly related to the labeled strain 1169-83 (74 to 100% at 60 degrees C and 75 to 100% at 75 degrees C; percent divergence, 0.0 to 2.5). Type strains of six other Aeromonas species were 45 to 66% related (60 degrees C) to strain 1169-83, but type strains of 27 Vibrio species were only 2 to 6% related. The name Aeromonas veronii is proposed for the highly related group of nine strains formerly known as Enteric Group 77. The type strain is designated as ATCC 35604 (CDC 1169-83). Strains of A. veronii grew well at 36 degrees C and had positive reactions at this temperature for indole, methyl red, Voges-Proskauer, citrate, lysine and ornithine decarboxylases, DNase, lipase, and motility; the strains had negative reactions for arginine decarboxylase, H2S, urea, and malonate. The following sugars were fermented: D-glucose (acid and gas), cellobiose (seven of nine strains), D-galactose, maltose, D-mannitol, D-mannose, alpha-methyl-D-glucoside (eight of nine strains), salicin, sucrose, and trehalose. The following sugars were not fermented: adonitol, L-arabinose, D-arabitol, dulcitol, erythritol, myo-inositol, lactose, raffinose, L-rhamnose, D-sorbitol, and D-xylose. The positive ornithine decarboxylase reaction differentiates A. veronii from other Aeromonas species. The antibiogram of A. veronii is typical of other Aeromonas strains (resistance to ampicillin and carbenicillin and susceptibility to most other agents). A. veronii strains were isolated from three clinical sources: respiratory secretions of four victims of drowning or near drowning in fresh water (probably not clinically significant); infected wounds of two patients previously exposed to fresh water (unknown clinical significance); and stools from three patients with diarrhea (probably clinically significant).

Leminorella is proposed as a new genus for the group of Enterobacteriaceae formerly known as Enteric Group 57. Strains of Leminorella gave positive tests for H2S production, acid production from L-arabinose and D-xylose, and tyrosine clearing; they were negative for indole production, Voges-Proskauer, urea hydrolysis, phenylalanine deaminase, motility, gelatin liquefaction, lysine and ornithine decarboxylases, arginine dihydrolase, growth in KCN, and acid production from adonitol, D-arabitol, cellobiose, erythritol, D-galactose, myo-inositol, lactose, maltose, D-mannitol, D-mannose, melibiose, alpha-CH3-glucoside, raffinose, L-rhamnose, salicin, D-sorbitol, sucrose, and trehalose. By DNA hybridization, strains of Leminorella were only 3 to 16% related to other Enterobacteriaceae and were divided into three groups. Leminorella grimontii is proposed as the type species for the genus and strain CDC 1944-81, ATCC 33999, is designated as the type strain. There were four strains of L. grimontii from stool specimens and two from urine specimens. L. richardii is proposed as the name for the second species (type strain, CDC 0978-82, ATCC 33998). All four L. richardii strains were from stool specimens. L. grimontii can be distinguished from L. richardii because it produces gas from glucose (100%) and acid from dulcitol (83%) and is methyl red positive (100%). One strain, CDC 3346-72, was more related to L. grimontii by DNA hybridization than to L. richardii, but the lower relatedness to both of these species indicated that it may be a third species. Biochemically it could not be distinguished from L. grimontii. All Leminorella strains were resistant (no zone of inhibition) to ampicillin, carbenicillin, and cephalothin. Some of the Leminorella strains were sent to us for Salmonella serotyping, and two reacted weakly in Salmonella antisera. The clinical significance of Leminorella is unknown.

Escherichia fergusonii (formerly known as Enteric Group 10) and Enterobacter taylorae (formerly known as Enteric Group 19) are proposed as new species in the family Enterobacteriaceae. By DNA hybridization (32P, 60 degrees C, hydroxyapatite), strains of E. fergusonii were 90 to 97% related to the type strain (holotype) ATCC 35469. They were most closely related to Escherichia coli and more distantly related to species in other genera. E. fergusonii strains are positive for indole production, methyl red, lysine decarboxylase, ornithine decarboxylase, and motility. They ferment D-glucose with gas production and also ferment adonitol, L-arabinose, L-rhamnose, maltose, D-xylose, trehalose, cellobiose, and D-arabitol. They are negative for Voges-Proskauer, citrate utilization (17% positive), urea hydrolysis, phenylalanine deamination, arginine dihydrolase, growth in KCN, and fermentation of lactose, sucrose, myo-inositol, D-sorbitol, raffinose, and alpha-methyl-D-glucoside. By DNA hybridization (32P, 60 degrees C, hydroxyapatite), strains of E. taylorae were 84 to 95% related to the type strain (holotype) ATCC 35317. Their nearest relative was E. cloacae, to which they were 61% related. Other named species were more distantly related. Strains of E. taylorae are positive for Voges-Proskauer, citrate utilization, arginine dihydrolase, ornithine decarboxylase, motility, growth in KCN medium, and malonate utilization. They ferment D-glucose with gas production and also ferment D-mannitol, L-arabinose, L-rhamnose, maltose, D-xylose, trehalose, and cellobiose. They are negative for indole production, methyl red, H2S production on triple sugar-iron agar, urea hydrolysis, phenylalanine deamination, lysine decarboxylase, gelatin hydrolysis, and fermentation of adonitol, i-inositol, D-sorbitol, and raffinose. Both new species occur in human clinical specimens. Two strains of E. fergusonii were isolated from blood. Five stains of E. taylorae were isolated from blood, and one was from spinal fluid. These blood and spinal fluid isolates suggest possible clinical significance, but this point requires further study.

The name Koserella trabulsii is proposed for a group of Enterobacteriaceae formerly called Enteric Group 45. This group consists of 12 strains that were originally identified as atypical Hafnia alvei. K. trabulsii strains were negative for indole production, Voges-Proskauer, H2S production, urea hydrolysis, phenylalanine deaminase, and acid production from glycerol, lactose, sucrose, and D-sorbitol; they were positive for methyl red, citrate (Simmons), lysine and ornithine decarboxylases, arginine dihydrolase (negative in 1 to 2 days and positive in 3 to 7 days), and acid production from cellobiose and melibiose; and they were resistant to the Hafnia-specific bacteriophage of Guinée and Valkenburg. They were tested for DNA relatedness by the hydroxyapatite method with 32PO4-labeled DNA from the designated type strain (CDC 3349-72, ATCC 35313). The 12 strains were 87 to 99% related in 60 degrees C reactions. Relatedness of K. trabulsii to 71 DNA hybridization reference strains of representative species of Enterobacteriaceae was 4 to 37%. It was 15 to 16% related to H. alvei. All strains were susceptible to nalidixic acid, sulfadiazine, gentamicin, kanamycin, and chloramphenicol, and 83% were susceptible to nalidixic acid, sulfadiazine, gentamicin, kanamycin, and chloramphenicol, and 83% were susceptible to tetracycline. Most of the strains were resistant or intermediate to penicillin, ampicillin, carbenicillin, colistin, and cephalothin. Five of the strains were isolated from wounds, three were from the respiratory tract, and one each was from a stool, knee fluid, water, and an unknown source. The clinical significance of this organism is not known; therefore, future studies should focus on its isolation and its relationship to human disease.

In 1972 there were only 11 genera and 26 species in the family Enterobacteriaceae. Today there are 22 genera, 69 species, and 29 biogroups or Enteric Groups. This paper is a review of all of the new organisms. It has a series of differential charts to assist in identification and a large chart with the reactions of 98 different organisms for 47 tests often used in identification. A simplified version of this chart gives the most common species and tests most often used for identification. The sources of the new organisms are listed, and their role in human disease is discussed. Fourteen new groups of Enterobacteriaceae are described for the first time. These new groups are biochemically distinct from previously described species, biogroups, and Enteric Groups of Enterobacteriaceae. The new groups are Citrobacter amalonaticus biogroup 1, Klebsiella group 47 (indole positive, ornithine positive), Serratia marcescens biogroup 1, and unclassified Enteric Groups 17, 45, 57, 58, 59, 60, 63, 64, 68, and 69.

Zusammenfassung Vorliegende Arbeit übt Kritik an der ungenauen und langwierigen konventionellen Bestimmung der den Diabetiker belastenden Kohlenhydrate in Bier. Es wirdein neues Verfahren auf biologisch-reduktometrischer Basis beschrieben, das wesentlich genauere Ergebnisse liefert und in viel kürzerer Zeit als die Konventionsmethode durchgeführt werden kann.

Vibrio fluvialis and Vibrio furnissii have been associated with diarrhea but have rarely been isolated in the United States. We received strains of V. fluvialis and V. furnissii that were isolated from the stool of a 1-month-old baby. A description of these two strains and the case history of the patient are given in this report.

From 1974 through 1981, 4,089 isolates of Salmonella typhi were phage typed at the Centers for Disease Control and nine regional laboratories in the United States. The most prevalent types were degraded Vi (27%), E1 (20.6%), A (9.8%), C1 (5.7%), untypable Vi (3.5%), W form (3.5%), D1 (3.4%), B3 (3.4%), and F1 (2.4%). There were less than 2% of each of the remaining types. The distribution of phage types for this time period was similar to that seen in the periods 1966-1969 and 1970-1973, except that phage type B3 was one of the 10 most prevalent types in 1974-1981 but was not seen in 1966-1973. Phage typing is presently the most valuable laboratory tool for differentiation of strains of S. typhi in epidemiological studies.

Three additional phage typing systems for Salmonella enteritidis, plasmid analysis, biochemical tests, and antimicrobial susceptibility tests, were used in an attempt to subdivide 30 phage type 8 (phage typing system used by the WHO International Center for Enteric Phage Typing, London, England) isolates. These isolates represented 18 different egg-related outbreaks (21 strains) and 9 reference strains or strains that were not egg-associated. Only 7 of the 30 strains (28%) were subdivided by one or more of the methods used; this included 3 of the 21 strains from egg-related outbreaks. Twenty-seven strains contained a 55-kb plasmid that is associated with S. enteritidis. Of 65 additional phages tested, 2 from the phage typing system obtained from the Pasteur Institute, Paris, France, were useful in differentiating the three strains that lacked the 55-kb plasmid. Although the results obtained for the 21 strains from egg-related outbreaks showed that the strains had minor phenotypic differences, the overall results suggested that the strains may represent a single clone. Studies are planned to test additional phages and other typing methods to see whether strains of phage type 8 can be further differentiated.

To determine the pandemic potential of Vibrio cholerae, one must demonstrate both the presence of O1 antigen and the production of enterotoxin (CT). Tissue culture or enzyme-linked immunosorbent assays (ELISAs) for CT have been limited to research and reference laboratories. A kit for detecting CT by reversed passive latex agglutination is now commercially available and was used to test 168 strains of V. cholerae O1 and non-O1. When compared with the routine ELISA, the latex test was 98% accurate (86 of 88) for serogroup O1 strains and 100% accurate (80 of 80) for non-O1 strains. For both O1 and non-O1 study strains, the sensitivity of the latex agglutination test was 0.97 and the specificity was 1.00 when results were compared with ELISA results. The latex test is commercially available and has the advantages of being less complicated and less time-consuming than the ELISA.

Airborne influenza virus transmission is depending on climate. Infected individuals are able to travel to any country in the world within one day. In this study we combine these two insights to investigate the influence of climate change on pandemic spreading patterns of airborne infectious diseases, like influenza. Well-known recent examples for pandemics are severe acute respiratory syndrome (SARS, 2002/2003) and H1N1 (Influenza A virus subtype, 2009), which have demonstrated the vulnerability of a strongly connected world.

To date, epidemiologic associations among strains of Salmonella typhi are based exclusively on phage typing, which may be of limited value if a common phage type is involved. Analysis of ribosomal RNA gene restriction patterns allows separation of most independently isolated strains of identical phage types. The sensitivity of the method is dependent on the restriction enzymes used to digest chromosomal DNA. It was highest for PstI, which separated 16 of 20 strains that belonged to 8 phage types including 3 untypable strains. Three strains differed in their phage types but had identical ribosomal RNA gene restriction patterns. Also, two pairs of strains indistinguishable by phage typing exhibited identical patterns; however, two of these strains were expected to be identical because they were isolated from two patients who were likely exposed to the same source. Ribosomal RNA gene restriction patterns appear to be stable. Thus, the method may complement phage typing and aid in further differentiation of strains.