bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibody fucosylation predicts disease severity in secondary dengue infection
Authors: Bournazos Stylianos , Vo Hoa Thi My , Duong Veasna , Auerswald Heidi , Ly Sowath , Sakuntabhai Anavaj , Dussart Philippe , Cantaert Tineke , Ravetch Jeffrey V.
Published: June 2021

IgG fucosylation predicts dengue severity

Secondary infections with dengue virus (DENV) can produce life-threatening symptoms, including thrombocytopenia and hemorrhagic disease, when preexisting DENV-reactive immunoglobulin G1 (IgG1) antibodies promote the infection of immune cells. Although severe dengue symptoms are associated with increased levels of afucosylated IgG1 glycoforms, it is unclear whether this is simply a result of the infection or if it is a preexisting phenomenon that can dictate susceptibility to this disease. Bournazos
et al.
studied the Fab and Fc structures of anti-DENV antibodies from patients before and after infection and with variable disease outcomes (see the Perspective by de Alwis and Ooi). They found that DENV infection induced specific increases in IgG1 afucosylation, and levels of afucosylated IgG1 could indeed predict dengue disease severity, making IgG1 fucosylation status a potentially useful prognostic tool for the treatment of dengue patients.

Science
, abc7303, this issue p.
1102
; see also abj0435, p.
1041
Antarctic surface temperature and elevation during the Last Glacial Maximum
Authors: Buizert Christo , Fudge T. J. , Roberts William H. G. , Steig Eric J. , Sherriff-Tadano Sam , Ritz Catherine , Lefebvre Eric , Edwards Jon , Kawamura Kenji , Oyabu Ikumi , Motoyama Hideaki , Kahle Emma C. , Jones Tyler R. , Abe-Ouchi Ayako , Obase Takashi , Martin Carlos , Corr Hugh , Severinghaus Jeffrey P. , Beaudette Ross , Epifanio Jenna A. , Brook Edward J. , Martin Kaden , Chappellaz Jérôme , Aoki Shuji , Nakazawa Takakiyo , Sowers Todd A. , Alley Richard B. , Ahn Jinho , Sigl Michael , Severi Mirko , Dunbar Nelia W. , Svensson Anders , Fegyveresi John M. , He Chengfei , Liu Zhengyu , Zhu Jiang , Otto-Bliesner Bette L. , Lipenkov Vladimir Y. , Kageyama Masa , Schwander Jakob
Published: June 2021

Antarctic paleotemperatures

It has been widely thought that East Antarctica was ∼9°C cooler during the Last Glacial Maximum, close to the ∼10°C difference between then and now determined independently for West Antarctica. Buizert
et al.
used borehole thermometry, firn density reconstructions, and climate modeling to show that the temperature in East Antarctica was actually only ∼4° to 7°C cooler during the Last Glacial Maximum. This result has important consequences for our understanding of Antarctic climate, polar amplification, and global climate change.

Science
, abd2897, this issue p.
1097
Extensive pleiotropism and allelic heterogeneity mediate metabolic effects of
IRX3
and
IRX5
Authors: Sobreira Débora R. , Joslin Amelia C. , Zhang Qi , Williamson Iain , Hansen Grace T. , Farris Kathryn M. , Sakabe Noboru J. , Sinnott-Armstrong Nasa , Bozek Grazyna , Jensen-Cody Sharon O. , Flippo Kyle H. , Ober Carole , Bickmore Wendy A. , Potthoff Matthew , Chen Mengjie , Claussnitzer Melina , Aneas Ivy , Nóbrega Marcelo A.
Published: June 2021

Obesity genes working together

The biological causes of obesity are not well understood. Sobreira
et al.
examined the chromatin interactions between key genes in a locus known for its associations with obesity in human patients. In addition to directly interrogating the connections between these genes and examining the mechanisms that regulate their activity, the authors used mouse models to study the target genes' effects on both adipose tissue and brain cells that play a role in regulating dietary preferences.

Science
, abf1008, this issue p.
1085
Skull and vertebral bone marrow are myeloid cell reservoirs for the meninges and CNS parenchyma
Authors: Cugurra Andrea , Mamuladze Tornike , Rustenhoven Justin , Dykstra Taitea , Beroshvili Giorgi , Greenberg Zev J. , Baker Wendy , Papadopoulos Zach , Drieu Antoine , Blackburn Susan , Kanamori Mitsuhiro , Brioschi Simone , Herz Jasmin , Schuettpelz Laura G. , Colonna Marco , Smirnov Igor , Kipnis Jonathan
Published: June 2021

Getting around the blood–brain barrier

The meninges comprise three membranes that surround and protect the central nervous system (CNS). Recent studies have noted the existence of myeloid cells resident there, but little is known about their ontogeny and function, and whether other meningeal immune cell populations have important roles remains unclear (see the Perspective by Nguyen and Kubes). Cugurra
et al.
found in mice that a large proportion of continuously replenished myeloid cells in the dura mater are not blood derived, but rather transit from cranial bone marrow through specialized channels. In models of CNS injury and neuroinflammation, the authors demonstrated that these myeloid cells have an immunoregulatory phenotype compared with their more inflammatory blood-derived counterparts. Similarly, Brioschi
et al.
show that the meninges host B cells that are also derived from skull bone marrow, mature locally, and likely acquire a tolerogenic phenotype. They further found that the brains of aging mice are infiltrated by a second population of age-associated B cells, which come from the periphery and may differentiate into autoantibody-secreting plasma cells after encountering CNS antigens. Together, these two studies may inform future treatment of neurological diseases.

Science
, abf7844, abf9277, this issue p.
eabf7844
, p.
eabf9277
; see also abj8183, p.
396
Sense codon reassignment enables viral resistance and encoded polymer synthesis
Authors: Robertson Wesley E. , Funke Louise F. H. , de la Torre Daniel , Fredens Julius , Elliott Thomas S. , Spinck Martin , Christova Yonka , Cervettini Daniele , Böge Franz L. , Liu Kim C. , Buse Salvador , Maslen Sarah , Salmond George P. C. , Chin Jason W.
Published: June 2021

Designing bacterial superpowers

Biological systems read all 64 triplet codons in DNA to encode the synthesis of proteins composed of 20 canonical amino acids. Robertson
et al.
created cells that do not read several codons and showed that this confers complete resistance to viruses, which normally rely on the host cell's ability to read all the codons in the viral genome to reproduce (see the Perspective by Jewel and Chatterjee). The authors reassigned each codon to several noncanonical amino acids (ncAAs). This advance enables the efficient synthesis of proteins containing three distinct ncAAs and the encoded synthesis of entirely noncanonical polymers and macrocycles.

Science
, abg3029, this issue p.
1057
; see also abi9892, p.
1040
MBD5 and MBD6 couple DNA methylation to gene silencing through the J-domain protein SILENZIO
Authors: Ichino Lucia , Boone Brandon A. , Strauskulage Luke , Harris C. Jake , Kaur Gundeep , Gladstone Matthew A. , Tan Maverick , Feng Suhua , Jami-Alahmadi Yasaman , Duttke Sascha H. , Wohlschlegel James A. , Cheng Xiaodong , Redding Sy , Jacobsen Steven E.
Published: June 2021

Methyl readers that repress transcription

DNA methylation is a conserved epigenetic mark required for gene silencing in many different organisms. However, how the methyl mark is able to silence genes is still largely unknown. Ichino
et al.
discovered two
Arabidopsis
proteins named MBD5 and MBD6 that are recruited to DNA by direct recognition of methylation. These methyl readers recruit the class C J-domain protein SILENZIO to chromatin to silence methylated genes and transposons. SILENZIO likely acts through its interaction with heat shock chaperone proteins.

Science
, abg6130, this issue p.
1434
CO
2
electrolysis to multicarbon products in strong acid
Authors: Huang Jianan Erick , Li Fengwang , Ozden Adnan , Sedighian Rasouli Armin , García de Arquer F. Pelayo , Liu Shijie , Zhang Shuzhen , Luo Mingchuan , Wang Xue , Lum Yanwei , Xu Yi , Bertens Koen , Miao Rui Kai , Dinh Cao-Thang , Sinton David , Sargent Edward H.
Published: June 2021

Potassium helps CO
2
compete in acid

Electrochemical reduction of carbon dioxide (CO
2
) is a promising means of converting this greenhouse gas into valuable fuels and chemicals. However, two competing reactions restrict the efficiency of this process. In base, much of the CO
2
is trapped as carbonate before reduction; in acid, protons outpace CO
2
at catching electrons from the cathode. Huang
et al.
report that a high dose of potassium ions can help to solve the latter problem. By concentrating potassium ions at the electrode, high selectivity toward CO
2
reduction at high current in acid is possible, which the authors attribute to electrostatic stabilization of the desired adsorbates.

Science
, abg6582, this issue p.
1074
Estimating epidemiologic dynamics from cross-sectional viral load distributions
Authors: Hay James A. , Kennedy-Shaffer Lee , Kanjilal Sanjat , Lennon Niall J. , Gabriel Stacey B. , Lipsitch Marc , Mina Michael J.
Published: June 2021

Estimating an epidemic’s trajectory is crucial for developing public health responses to infectious diseases, but case data used for such estimation are confounded by variable testing practices. We show that the population distribution of viral loads observed under random or symptom-based surveillance—in the form of cycle threshold (Ct) values obtained from reverse transcription quantitative polymerase chain reaction testing—changes during an epidemic. Thus, Ct values from even limited numbers of random samples can provide improved estimates of an epidemic’s trajectory. Combining data from multiple such samples improves the precision and robustness of this estimation. We apply our methods to Ct values from surveillance conducted during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in a variety of settings and offer alternative approaches for real-time estimates of epidemic trajectories for outbreak management and response.
Comment on “Individual heterozygosity predicts translocation success in threatened desert tortoises”
Authors: Hansson Bengt , Morales Hernán E. , van Oosterhout Cock
Published: June 2021

Scott
et al
. (Reports, 27 November 2020, p. 1086) bring much-needed attention to species conservation by demonstrating heterozygote superiority among translocated tortoises. However, we believe that their recommended heterozygosity decision rule risks taking conservation genomics backward. We argue that their advice could misguide conservation management aimed at establishing viable populations, and that it can be improved by also assessing the genetic load.
When sharks nearly disappeared
Authors: Pimiento Catalina , Pyenson Nicholas D.
Published: June 2021

A previously unidentified extinction event in the open ocean decimated pelagic sharks
Inhibition of Phagocytosis-Associated Chemiluminescence by Superoxide Dismutase
Authors: Webb Lawrence S. , Keele Bernard B. , Johnston Richard B.
Published: June 2021

During the process of phagocytosis, human leukocytes emit a burst of luminescence which can be measured in a liquid scintillation spectrometer. The enzyme superoxide dismutase, which removes superoxide anions (O
·
), inhibited this chemiluminescence by 70% at a concentration of 100 μg/ml. The enzyme did not inhibit phagocytosis. These results support other studies indicating that O
·
is elaborated by phagocytizing leukocytes. They also indicate that O
·
plays a major role in phagocytosis-associated chemiluminescence, though not necessarily as the luminescing agent. Catalase and benzoate inhibited the chemiluminescence of phagocytosis to a slight extent, suggesting that hydrogen peroxide and hydroxyl radical, respectively, might also be involved in this phenomenon. The relationship between the mediators of chemiluminescence and those responsible for phagocytic bactericidal activity remains to be defined.
Serological response of chickens to Salmonella thompson and Salmonella pullorum infections
Authors: Williams J E , Whittemore A D
Published: June 2021

Chickens were experimentally infected with Salmonella thompson (serogroup C, paratyphoid) and Salmonella pullorum (serogroup D). Five serological methods and one cultural method were used in detecting the infections. The microantiglobulin test was superior to all other methods for detection of paratyphoid (S. THOMPSON) infection and was followed in efficacy by the microagglutination test, rapid serum plate test, cloacal swab culture, macroscopic tube agglutination test, and rapid whole-blood test, in that order. Birds infected with S. pullorum showed much higher agglutinin titers than the birds infected with paratyphoid. The microagglutination and microantiglobulin tests were not significantly different for detection of pullorum infection and were followed in efficacy by the rapid serum plate, macroscopic tube agglutination, rapid whole-blood, and cloacal swab culture tests, in that order. The cloacal swab culture test was totally inadequate for the detection of pullorum infection.
O serotyping of Providencia stuartii isolates collected from twelve hospitals
Authors: Penner J L , Hinton N A , Duncan I B , Hennessy J N , Whiteley G R
Published: June 2021

A collection of 829 isolates of Providencia stuartii, mostly from urological specimens of patients in 12 hospitals, were O serotyped. Hospitals varied in serotype distribution, but most isolates (97%) fell into one or another of 14 O types of P. stuartii. One type (O63) was found in 10 hospitals, and six types (O4, O17, O25, O52, O55, O56) were found in 5 or more hospitals. These seven types were more common than others and included 753 (91%) of the isolates. Only four isolates agglutinated in Providencia alcalifaciens antisera and, for increased efficiency in serotyping, it is recommended that separate schemes be employed for P. stuartii and P. alcalifaciens. Strains endemic in different hospitals may differ in serotype and give rise to nosocomial infections that are clinically recognizable when infections occur in obvious clusters. Nosocomial infections occurring in low frequency among patients not located close to each other in the hospital may be detected with the aid of serotyping.
Pseudocoagulase activity of staphylococci
Authors: Wegrzynowicz Z , Heczko P B , Jeljaszewicz J , Neugebauer M , Pulverer G
Published: June 2021

A total of 245 strains of staphylococci isolated from various pathological specimens derived from cases of human infections was tested for staphylocoagulase activity. Test systems employing normal citrated rabbit plasma and the same substrate supplemented with inhibitors of thrombin and proteolytic enzymes (but not influencing the staphylocoagulase activity) were used for testing suspensions of bacteria and cell-free culture supernatants. A total of 237 strains clotted normal rabbit plasma; however, addition of Trasylol and heparin resulted in positive results in 222 strains, whereas plasma supplemented with Trasylol and hirudin was coagulated definitely by only 173 strains. It is postulated that proteolytic enzymes of staphylococci interfere with staphylocoagulase-induced clotting and may simulate coagulase-positive activity of staphylococci. To avoid such false results, a test system for detection of staphylocoagulase should include proteolytic enzyme inhibitors. Possible mechanisms of these findings are discussed.
Accuracy and reproducibility of the Oxi/Ferm system in identifying a select group of unusual gram-negative bacilli
Authors: Nadler H , George H , Barr J
Published: June 2021

The Oxi/Ferm (O/F) identification system was compared in a double-blind study to a conventional test battery for the characterization of 96 reference and clinical strains consisting of 83 nonfermentative and 13 oxidase-producing, fermentative gram-negative bacilli. The O/F tube and supplemental tests correctly identified 84% of the nonfermentative and 77% of the oxidase-producing, fermentative bacilli. However, when the supplemental tests were excluded and the biochemical profiles generated by all nine O/F tube reactions were examined, the profile accuracy reached 95% (79 of 83) for the nonfermentative and 93% (12 of 13) for oxidase-producing, fermentative bacilli. Seven of the nine O/F substrate reactions demonstrated less than or equal to 89% agreement with conventional reactions, whereas the urea and arginine reactions provided 82 and 85% agreement, respectively. Replicate O/F tests with six selected organisms demonstrated 97% identification reproducibility and 84% overall substrate reproducibility. The mean O/F identification time was 2.6 days as compared to 3.3 days for the conventional system. Although this study suggests that the O/F system is a convenient, rapid, and accurate alternative to conventional identification methods, several modifications are recommended.
Incidence of "oxidase-variable" strains of Aeromonas hydrophila
Authors: Overman T L , D'Amato R F , Tomfohrde K M
Published: June 2021

Certain strains of Aeromonas hydrophila are oxidase negative when grown on gram-negative selective and differential media. Of 100 strains of A. hydrophila examined, 8 were found to possess this characteristic. Information is provided on how to detect these common variants of A. hydrophila.
Effect of blood dilution on recovery of organisms from clinical blood cultures in medium containing sodium polyanethol sulfonate
Authors: Salventi J F , Davies T A , Randall E L , Whitaker S , Waters J R
Published: June 2021

This clinical study was designed to evaluate the standard laboratory protocol that requires blood specimens be diluted with greater than or equal to 10 volumes of media. Blood was collected from hospitalized patients, and 1 ml was inoculated into each of three vials containing 2.3, 7.3, and 24 ml of BACTEC 6B aerobic medium resulting in dilutions of 1:4, 1:10, and 1:30, respectively. The three test vials were treated identically, and the study was carried out at four hospitals. Of the 2,550 sets of vials inoculated, 174 were positive with clinically significant isolates from 105 patients. There was no difference in the number of positive cultures recovered by 24 h (67%) or 48 h (90%) from any dilution. These percentages agreed with other reports from BACTEC users. The number of positive vials (139, 144, 147, respectively) at each dilution was not significantly different, indicating that all three dilutions showed equal recovery of pathogenic microorganisms. Despite this overall equality, two patients, one on antibiotic therapy, were found to have correlated cultures which failed to grow at the 1:4 dilution. This finding implies that a 1:4 dilution of blood cannot be recommended unequivocably despite the higher overall recovery rate of positive cultures.
Isolation of Clostridium botulinum from Honey
Authors: Midura T F , Snowden S , Wood R M , Arnon S S
Published: June 2021

Methods for the isolation of Clostridium botulinum from honey samples are described. A total of 9 of 90 honey samples were positive for C. botulinum; 6 of the positive samples had been fed to babies who developed infant botulism.
Invasive strain of Escherichia coli belonging to O group 29
Authors: Toledo M R , Reis M H , Almeida R G , Trabulsi L R
Published: June 2021

A strain of Escherichia coli isolated from a child with diarrhea was biochemically similar and antigenically identical (O and K antigens) to the standard strain of E. coli O group 29 and was positive in the Serény test for invasiveness, which suggests that it can cause a Shigella-like illness.
Modification of the Bile Solubility Test for Rapid Identification of
Streptococcus pneumoniae
Authors: Murray Patrick R.
Published: June 2021

A modified bile solubility test is described which can be used to presumptively identify
Streptococcus pneumoniae
recovered in blood culture.
Pleocytosis and immunoglobulin changes in cerebrospinal fluid and herpesvirus serology in patients with Guillain-Barré syndrome
Authors: Link H , Wahren B , Norrby E
Published: June 2021

In a follow-up study of 24 patients with Guillain-Barré syndrome, 55% developed a cerebrospinal fluid (CSF) mononuclear pleocytosis, which persisted for 4 months or more. Raised index values of CSF-immunoglobulin G (IgG), CSF-IgA, and CSF-IgM, indicating synthesis of the immunoglobulin in question in the central nervous system, were found in 63, 35, and 25%, respectively. Agarose gel eletrophoresis revealed oligoclonal immunoglobulin in CSF in 21% and in both CSF and serum in another 21% of the patients. Twenty-five percent had abnormally low kappa/lambda ratios of CSF and/or serum, indicating synthesis of oligoclonal immunoglobulin, mainly of the lambda light-chain type. The inflammatory reaction in the central nervous system, as reflected by pleocytosis, immunoglobulin synthesis, and oligoclonal immunoglobulin, was not correlated to the severity or course of Guillain-Barré syndrome. A raised CSF-IgM index and oligoclonal immunoglobulin were found more often in the Guillain-Barré syndrome patients who displayed pleocytosis. All patients had or developed antibodies to Epstein-Barr virus. Three patients had serology indicating a primary infection, 11 patients had antibody changes indicating a reactivated infection, and 10 had serology indicating previous exposure. Two patients showed serological evidence for a primary cytomegalovirus infection, 2 had serology indicative of a reactivated infection, 12 had titers as caused by previous exposure, and 8 remained seronegative. Virus-specific IgM was measurable in all cases of primary infection. Neither primary or reactivated Epstein-Barr virus nor cytomegalovirus infections were obviously related to CSF pleocytosis.
Hen Fluorescein-Labeled Gonococcal Lipopolysaccharide Antibody in the Delayed Fluorescent Antibody Technique for the Confirmation of
Neisseria gonorrhoeae
Authors: Ashton F. E. , Leitch R. A. , Perry M. B. , Wallace R. , Diena B. B.
Published: June 2021

A fluorescent antibody reagent (termed anti-LPS conjugate) was prepared from sera obtained from hens immunized with gonococcal R-type lipopolysaccharide. The reagent was absorbed with Formalin-treated cells of
Neisseria meningitidis.
The anti-LPS conjugate gave uniform brilliant staining of
Neisseria gonorrhoeae
with little background fluorescence, thus making interpretation and reading of fluorescence simple. The conjugate did not significantly stain cultures of
N. meningitidis, Neisseria lactamica
, nonpathogenic
Neisseria
species, or other gram-negative bacteria. Several preparations of the conjugate provided the same specificity and reproducibility of staining. The anti-LPS conjugate was compared with Difco Laboratories fluorescent antibody conjugate for staining of
N. gonorrhoeae.
Both conjugates stained cells of the light and dark variants of gonococcal colony types 1 and 2, as well as cells of colony types 3 and 4. When used for the confirmation of
N. gonorrhoeae
, the anti-LPS and Difco conjugates stained 426 of 431 (98.8%) and 210 of 213 (98.6%) of the gonococcal cultures, respectively. Absorption of the anti-LPS conjugate with R-type lipopolysaccharide removed the staining of gonococci. However, absorption of Difco conjugate with R-type lipopolysaccharide did not remove the staining of gonococci, suggesting that the majority of fluorescein-labeled antibody present in the Difco conjugate is directed to gonococcal cell surface components other than lipopolysaccharide. The results of this study indicate that fluorescein-labeled gonococcal lipopolysaccharide antibody should be a reliable fluorescent antibody reagent for the confirmation of
N. gonorrhoeae.
Comparison of indirect hemagglutination and indirect immunofluorescence tests with microneutralization tests for detection of type-specific Herpesvirus hominis antibody
Authors: Johnson L D , Fuccillo D A , Stalder H , Oxman M A , Fraser C E , Madden D L
Published: June 2021

Indirect hemagglutinating and immunofluorescent antibody responses to Herpesvirus hominis types 1 and 2 were compared to neutralizing antibody responses in infected humans from whom H. hominis type 1 or 2 was isolated. The indirect immunofluorescent antibody test was shown to be the most sensitive and specific for primary human infections. The sensitivity and specificity of the indirect hemagglutination and the immunofluorescent antibody tests were shown to be equal to that of the microneutralization test among patients who had primary or recurrent H. hominis type 2 infections. It is suggested that the indirect hemagglutination test is preferable for assaying large populations for previous infection with H. hominis type 2 because it is rapid, easier to perform, and more economical. The intermediate range of titer differences (deltat) between H. hominis types 1 and 2 previously reported to be due to infections with both viruses was shown to occur in all three tests among patients with primary infections with either virus.
Simple, differential staining technique for enumerating rickettsiae in yolk sac, tissue culture extracts, or purified suspensions
Authors: Silverman D J , Fiset P , Wisseman C L
Published: June 2021

A differential staining method employing acridine orange-stained rickettsiae and safranin-stained standardized suspensions of Shigella dysenteriae is described for enumerating rickettsiae harvested during various stages of the growth cycle.
Improved blood culture medium for radiometric detection of yeasts
Authors: Hopfer R L , Mills K , Gröschel D
Published: June 2021

The influence of medium composition on the rate of CO2 production by yeasts in simulated blood cultures was determined in the Bactec radiometric system. A yeast nitrogen base broth containing [14C]glucose and Triton X-100 allowed the detection of positive cultures earlier than the regular Bactec blood culture media.
Exotoxin activity associated with the Legionnaires disease bacterium
Authors: Baine W B , Rasheed J K , Mackel D C , Bopp C A , Wells J G , Kaufmann A F
Published: June 2021

Hemolysis occurred around growth of the Legionnaires disease bacterium on supplemented Mueller-Hinton agar containing sterile defibrinated blood from each of five mammalian species. Hemolysis was most pronounced with guinea pig or rabbit blood, was less intense with horse or sheep blood, and was slight with blood from a human donor. Sterile filtrates of allantoic fluid from embryonated hen's eggs that had been infected with this organism displayed hemolytic activity in a radial hemolysis assay with guinea pig cells in agar. Growth of the Legionnaires disease bacterium on F-G agar with 5% hen's egg yolk was surrounded by a zone of clearing and more circumscribed zones of iridescence and increased opacity on and in the medium. Attempts to detect activity analogous to that of Escherichia coli heat-labile or heat-stable enterotoxin in allantoic fluid from infected eggs or in cultures of the Legionnaires disease bacterium were not successful.
Use of colony pools for diagnosis of enterotoxigenic Escherichia coli diarrhea
Authors: Merson M H , Sack R B , Kibriya A K , Al-Mahmood A , Adamed Q S , Huq I
Published: June 2021

Diagnosis of enterotoxigenic Escherichia coli diarrhea was made in 109 adult males with an acute dehydrating cholera-like syndrome in Dacca, Bangladesh, by testing 10 colonies isolated from admission stool specimens for production of heat-labile and heat-stable toxins. Toxin testing of one colony yielded a diagnosis in 92% of the cases, testing of two colonies yielded a diagnosis in 95% of the cases, testing of a pool of 5 colonies yielded a diagnosis in 95% of the cases, and testing of a pool of 10 colonies yielded a diagnosis in 96% of the cases. From stool cultures obtained on subsequent days, toxin testing of individual colonies and pools revealed diminished efficacy of pooling with decreasing numbers of enterotoxin-positive isolates in the pool. To detect the presence of enterotoxigenic E. coli in stools, toxin testing of 5 individual isolates and a pool of 10 colonies was found to be almost as effective as the testing of 10 individual isolates.
Extractable Antigen Shared by
Peptostreptococcus anaerobius
Strains
Authors: Graham Mitchell B. , Falkler William A.
Published: June 2021

Extracts from several species of gram-positive cocci were prepared by a modification of the Rantz-Randall autoclave method and tested for reactions with rabbit anti-
Peptostreptococcus anaerobius
(ATCC 27337 and VPI 5737) sera in a capillary precipitin test. Antigen preparations from two reference strains of
P. anaerobius
(ATCC 27337 and VPI 5737) and six clinical isolates of
P. anaerobius
reacted with the
P. anaerobius
antisera. These extracts formed a line of identity by immunodiffusion and displayed at least one precipitin line by immunoelectrophoresis. Absorption of the antisera with either the autoclaved extract or a 10% whole-cell suspension from each of the eight
P. anaerobius
strains removed the precipitin line(s) observed during immunodiffusion and immunoelectrophoresis. Extracts prepared to other species of
Peptococcus, Peptostreptococcus
, and
Streptococcus
did not react with the
P. anaerobius
antisera in a capillary precipitin test. In addition antisera to Lancefield groups A to G did not react with the extracts from the eight
P. anaerobius
strains. Preliminary chemical analysis of the extracts from the eight strains showed that they contained approximately 0.2 mg of carbohydrate per ml and 3.6 mg of protein per ml. The rabbit anti-
P. anaerobius
sera used in this study detected a common antigen(s) shared by strains of
P. anaerobius
, but did not react with autoclave extracts prepared from other species of gram-positive cocci. This extractable antigen could be used in a capillary precipitin test to rapidly identify
P. anaerobius
strains isolated in the clinical microbiology laboratory.
Nuclease enhancement of specific cell agglutination in a serodiagnostic test for Neisseria gonorrhoeae
Authors: Arko R J , Wong K H , Peacock W L
Published: June 2021

Antiserum to a purified type R lipopolysaccharide antigen isolated from Neisseria gonorrhoeae was used in a slide agglutination test and compared with conventional carbohydrate utilization and fluorescent antibody tests to confirm the identity of laboratory cultures classified as typical or "atypical" N. gonorrhoeae. Cultures of Corynebacterium vaginalis, N. meningitidis, N. catarrhalis, N. sicca, and N. lactamicus were also tested in the slide agglutination procedure. The addition of both deoxyribonuclease and ribonuclease (1 mg/ml) to the cell suspension medium of phosphate-buffered saline improved the sensitivity and specificity of the agglutination reaction for N. gonorrhoeae. Problems relating to the agglutination test as an aid in identification of N. gonorrhoeae are discussed.
First isolation of Peptococcus indolicus from a human clinical specimen
Authors: Bourgault A M , Rosenblatt J E
Published: June 2021

Peptococcus indolicus was isolated from a skin lesion of a sheepherder. A case report is given, and microbiological features of this organism are described.
Methods for serotyping nasopharyngeal isolates of Haemophilus influenzae: slide agglutination, Quellung reaction, countercurrent immunoelectrophoresis, latex agglutination, and antiserum agar
Authors: Ingram D L , Collier A M , Pendergrass E , King S H
Published: June 2021

Nasopharyngeal isolates of H. influenzae were typed by the slide agglutination test, the Quelling reaction, the latex agglutination test, countercurrent immunoelectrophoresis, and the antiserum agar test. These tests gave essentially comparable results, with countercurrent immunoelectrophoresis and latex agglutination being slightly more sensitive. Cross-reactive problems encountered with latex agglutination and the expense of performing countercurrent immunoelectrophoresis or the antiserum agar test made these tests less practical than the slide agglutination test to identify single strains that were already isolated. The Quellung reaction and slide agglutination were the most rapid tests used to type an organism. For mass screening of multiple samples, countercurrent immunoelectrophoresis was the simplest technique. The antiserum agar test was slow but was the best technique to screen nasopharyngeal swab cultures to identify the presence of any encapsulated strains in the mixed flora. Whether any of the above techniques were as sensitive as the immunofluorescence test was not evaluated in this study.
Comparison of three methods for identification of pathogenic Neisseria species
Authors: Appelbaum P C , Lawrence R B
Published: June 2021

A radiometric procedure was compared with the Minitek and Cystine Trypticase Agar sugar degradation methods for identification of 113 Neisseria species (58 Neisseria meningitidis, 51 Neisseria gonorrhoeae, 2 Neisseria lactamica, 2 Neisseria sicca). Identification of meningococci and gonococci was confirmed by agglutination and fluorescent antibody techniques, respectively. The Minitek method identified 97% of meningococci, 92% of gonococci, and 100% of other Neisseria after 4 h of incubation. The radiometric (Bactec) procedure identified 100% of gonococci and 100% of miscellaneous Neisseria after 3 h, but problems were encountered with meningococci: 45% of the later strains yielded index values for fructose between 20 and 28 (recommended negative cut-off point, less than 20), with strongly positive (greater than 100) glucose and maltose and negative o-nitrophenyl-beta-D-galactopyranoside reactions in all 58 strains. The Cystine Trypticase Agar method identified 91% of meningococci, 90% of gonococci, and 100% of other Neisseria after 24 to 48 h. Prolongation of the Cystine Trypticase Agar incubation period led to abnormal lactose/sucrose reactions in some meningococci and gonococci. Radiometric and Minitek systems are more accurate and convenient than Cystine Trypticase Agar techniques, but, on the basis of these results, radiometric fructose sensitivity levels for meningococci need reevaluation.
Development of a chemically defined liquid medium for growth of Legionella pneumophila
Authors: Pine L , George J R , Reeves M W , Harrell W K
Published: June 2021

A chemically defined liquid medium has been developed for the study of the physiology and antigen production of the Legionnaires disease bacterium. The medium contains basal salts, vitamins, alpha-ketoglutaric acid, pyruvate, 0.05% l-cysteine, 0.05% glutathione, and a mixture of 20 additional amino acids, each of 0.01% final concentration, except serine, which was at 0.1%. The medium in shake culture at 37 degrees C with increased CO2 at pH 6.5, supports the maximum rate of growth, the highest cell yields, and the maximum cell surface antigen as distinguished by specific fluorescein isothiocyanate-conjugated antibody. Studies during the development of this medium showed that CO2, pyruvate, and alpha-ketoglutarate strongly stimulated growth; that cysteine and methionine were required for growth; and that serine, threonine, histidine, tyrosine, and tryptophane were energy sources. Glutathione substituted for cysteine, but cystine did not. The organisms did not use glucose and polysaccharides, as judged by cell yields when these carbohydrates were present or absent. The chelators malate, citrate, and ethylenediaminetetraacetic acid totally inhibited growth. Beta-mercaptoethanol, thioglycolate, dithiothreitol, and Tween 80 (0.05%) inhibited growth strongly or completely. Catalase activity was extremely weak or absent. Morphology varied, depending upon conditions and phases of growth. In general, filamentous forms became chains of cigar-shaped bacilli fragmenting to pairs and becoming coccoidal in the late stationary pha-e of growth. The organism grew at 25, 30, and 37 degrees C. Although they varied in their growth characteristics, 10 isolates were passed for five transfers in the chemically defined broth, giving maximum rates of growth, cell yields, and antigen production.
Survival of anaerobic bacteria in common laboratory diluents
Authors: Casciato D A , Rosenblatt J E
Published: June 2021

The survival of six species of anaerobic bacteria was studied in simple or commercially available diluents. Bacteroides fragilis and Fusobacterium nucleatum showed excellent survival in all diluents including distilled water. Fusobacterium mortiferum survived well in all diluents except water and water supplemented with 0.1% gelatain. Clostridium perfringens survived best in phosphate-buffered saline with gelatin. Peptococcus asaccharolyticus required gelatin added to the basic diluent, and Streptococcus intermedius showed excellent survival only in minimal essential medium with gelatin. These diluents could provide effective and economical alternatives to more complex and costly diluents often used in work with anaerobic bacteria.
Recovery of Angiostrongylus cantonensis from cerebrospinal fluid of a child with eosinophilic meningitis
Authors: Kuberski T , Bart R D , Briley J M , Rosen L
Published: June 2021

Viable Angiostrongylus cantonensis was recovered from the cerebrospinal fluid of a 17-month-old boy with eosinophilic meningitis. Neurological findings were minimal, and the child had an uneventful recovery.
Isolation of oxidase-negative Pseudomonas aeruginosa from sputum culture
Authors: Hampton K D , Wasilauskas B L
Published: June 2021

Two isolates of Pseudomonas aeruginosa lacking characteristic indophenol oxidase were recovered from a sputum specimen. A discussion of the characteristic biochemical tests and antibiograms along with a possible explanation for this phenomenon is presented.
Fasle-positive macroscopic appearance of blood cultures in sorbitol-containing hypertonic medium
Authors: Welch D F , Kelly M T
Published: June 2021

Inability to rely on macroscopic examination as an aid in identifying positive blood cultures was encountered when a hypertonic medium containing sorbitol was tested in a comparative study with an isotonic blood culture medium.
Improved Procedure for Transport of Dental Plaque Samples and Other Clinical Specimens Containing Anaerobic Bacteria
Authors: Spiegel Carol A. , Minah Glenn E. , Krywolap George N.
Published: June 2021

An improved transport system for samples containing anaerobic bacteria was developed. This system increased the recovery rate of anaerobic bacteria up to 28.8% as compared to a commonly used method.
Characterization of anaerobic gram-negative bacilli by using rapid slide tests for beta-lactamase production
Authors: Bourgault A M , Rosenblatt J E
Published: June 2021

A total of 175 isolates of anaerobic gram-negative bacilli were tested for beta-lactamase production by using a slide test modification of the chromogenic cephalosporin (Nitrocefin, Glaxo, Middlesex, England) assay and the iodometric slide test. Included isolates were Bacteroides melaninogenicus (46), B. fragilis (78), other Bacteroides isolates (21), Fusobacterium (25), and other gram-negative bacilli (5). Both slide tests detected 25 B. melaninogenicus isolates that were beta-lactamase producers (minimal inhibitory concentration of penicillin was greater than 0.78 micrograms/ml). beta-Lactamase produced by the other gram-negative anaerobes could only be detected by the Nitrocefin assay. This assay was positive in 70 or 77 B. fragilis against which the minimal inhibitory concentration of penicillin was greater than 0.78 micrograms/ml. Ten of 11 other species of Bacteroides against which the minimal inhibitory concentration of penicillin was greater than 0.78 micrograms/ml were also Nitrocefin test positive. Minimal inhibitory concentrations of penicillin against all isolates of Fusobacterium and unidentifified gram-negative bacilli were less than or equal to 0.78 micrograms/ml and were Nitrocefin assay negative. beta-Lactamase-producing strains of B. melaninogenicus can be differentiated because both the slide iodometric and Nitrocefin assays will be positive, whereas beta-lactamase produced by other Bacteroides will only be detected by the Nitrocefin assay. Such penicillin-resistant isolates could be detected and reported to clinicians before final identification.
Modified metabolic inhibition test for serotyping strains of Ureaplasma urealyticum (T-strain Mycoplasma)
Authors: Robertson J A , Stemke G W
Published: June 2021

Antisera prepared against the eight recognized serotypes of Ureaplasma urealyticum were tested against the homologous and heterologous antigens by a modified metabolic inhibition test that used bromothymol blue broth in microtiter plates. The method gives clear endpoint determinations which are usually maintained on continued incubation. Antisera against serotype 8 showed cross-reactions with types 2 and 4. The ninth strain, Vancouver, when tested by this method did not fit the recognized serotyping scheme and may represent a new serotype.
Collagenase in equine cell culture preparation
Authors: Lang G
Published: June 2021

Equine kidney cells disaggregated by treatment with 0.01% collagenase were used in the preparation of primary monolayer cell cultures. The primary cells could be stored for long periods in liquid nitrogen and subsequently subcultivated. These techniques provided a long-term supply of equine kidney cells, free of apparent contamination, from the kidneys of a single fetus.
CRISPR-Cas9 Gene Editing in Yeast: A Molecular Biology and Bioinformatics Laboratory Module for Undergraduate and High School Students
Authors: Sankaran Saumya M. , Smith Justin D. , Roy Kevin R.
Published: June 2021

CRISPR-Cas9 genome editing technology is widely used in scientific research and biotechnology. As this technology becomes a staple tool in life sciences research, it is increasingly important to incorporate it into biology curricula to train future scientists.
Paired Multiple-Choice Questions Reveal Students’ Incomplete Statistical Thinking about Variation during Data Analysis
Authors: Hicks Jenna , Dewey Jessica , Abebe Michael , Brandvain Yaniv , Schuchardt Anita
Published: June 2021

Biologists consider variability during biological investigations. A robust quantitative understanding of variability is particularly important during data analysis, where statistics are used to quantify variation and draw conclusions about phenomena while accounting for variation.
Complete Genome Sequence of
Geobacter
sp. Strain SVR, an Antimonate-Reducing Bacterium Isolated from Antimony-Rich Mine Soil
Authors: Warashina Tomoro , Yamamura Shigeki , Suzuki Haruo , Amachi Seigo , Arakawa Kazuharu
Published: June 2021

We report here the complete genome sequence of
Geobacter
sp. strain SVR, isolated from antimony mine soil in Nakase Mine, Hyogo Prefecture, Japan. SVR strains proliferate using antimonate [Sb(V)] as an electron acceptor, providing insights into the antimony reduction mechanism.
Cyanophage Diversity and Community Structure in Dead Zone Sediments
Authors: Broman Elias , Holmfeldt Karin , Bonaglia Stefano , Hall Per O. J. , Nascimento Francisco J. A.
Published: June 2021

Cyanophages are viruses that target cyanobacteria and directly control their abundance via viral lysis. Cyanobacteria are known to cause large blooms in water bodies, substantially contributing to oxygen depletion in bottom waters resulting in areas called dead zones.
Permafrost thaw induced abrupt changes in hydrology and carbon cycling in Lake Wudalianchi, northeastern China
Authors: Yao Yuan , Huang Yongsong , Zhao Jiaju , Wang Li , Ran Youhua , Liu Weiguo , Cheng Hai
Published: June 2021

Lakes in the permafrost zone have been proposed to serve as key outlets for methane and carbon dioxide emissions. However, there has been no geological record of the hydrological and biogeochemical responses of lakes throughout the thawing of surrounding permafrost. We use multiple biomarker and isotopic proxies to reconstruct hydrological and biogeo-chemical changes in Lake Wudalianchi in northeastern China during regional thawing of the permafrost. We show permafrost thawing, as indicated by lignin degradation, initiated rapid lake water freshening as a result of the opening of groundwater conduits, and negative organic δ13C excursion due to increased inorganic and organic carbon fluxes. These hydro-logical changes were followed, with an ∼5–7 yr delay, by abrupt and persistent increases in microbial lake methanotrophy and methanogenesis, indicating enhanced anaerobic organic decomposition and methane emissions from lakes as permafrost thaws. Our data provide a detailed assessment of the processes involved during permafrost thaw, and highlight the importance of lakes in ventilating greenhouse gases to the atmosphere.
Catheter insertion depths in less-invasive surfactant administration
Authors: Maiwald Christian Achim , Neuberger Patrick , Franz Axel R , Engel Corinna , Michel Jörg , Esser Michael , Poets Christian F
Published: June 2021

Introduction

Less-invasive surfactant administration (LISA) under continuous positive airway pressure is increasingly used for the treatment of neonatal respiratory distress. Different procedures are described, but data on the optimal catheter insertion depth are sparse.

Objective

To generate data for recommending an optimal catheter insertion depth in LISA.

Methods

We examined 112 anterior–posterior chest X-rays from intubated infants and determined the carina’s vertebral projection, whenever possible. After that, distances between the middle of cervical vertebra 4 (C4) and thoracic vertebra 2 and the middle of C4 to thoracic vertebra 3, respectively, were measured. Results were plotted against infant’s weight.

Results

A weight-based chart and recommendations for the optimal intratracheal catheter position in infants with a body weight between 350 and 4000 g were created.

Conclusions

Generated data offer standardisation and may thus help to find a balance between risk of surfactant reflux and unilateral surfactant administration.
Unusual giant pleural lipomas: imaging features
Authors: Sudhakaran Dipin , Chandrashekhara Sheragaru Hanumanthappa , Kumar Sunil , Sulaiman Mohamed
Published: June 2021

Pleural lipomas are rarely encountered in the thoracic cavity. Sometimes, they infiltrate the intercostal space to have a component on either side of the intercostal space forming a hourglass configuration. They are generally solitary, small and asymptomatic. We present the case of a 49-year-old man with two giant pleural lipomas, both originating from the right parietal pleura, and one of which was passing through the intercostal space giving rise to a hourglass-shaped configuration. When they occur, although benign, considering the evolutionary potential, excision is recommended.
Cystic artery pseudoaneurysm due to carcinoma of the gallbladder
Authors: Mahalingam Sudharshan , Shaikh Oseen Hajilal , Kumbhar Uday Shamrao , Mohan Amuthabharathi
Published: June 2021

A 52-year-old man, with known case of hypertension and stroke, presented to us with an upper gastrointestinal bleed and abdominal pain. Ultrasonography of the abdomen showed haematoma within the gallbladder (GB), and Doppler ultrasound was suggestive of an aneurysm arising from the cystic artery (CA). CT of the abdomen showed a well-enhancing thick-walled GB suggestive of malignancy. It also showed the presence of a double CA along with an aneurysm of one of the cystic arteries, haematoma within the GB and haemoperitoneum. Digital subtraction angiography confirmed the presence of double CA and CA pseudoaneurysm. The CA was selective catheterised and embolised withN-butyl cyanoacrylate glue. The patient underwent extended radical cholecystectomy later and was reported to have adenocarcinoma of the GB.
Extra-axial haemorrhage in a patient with Alport syndrome after epidural anaesthesia
Authors: Wijayanayaka Shanika , Guha Abir , Sivanesan Kanapathippillai , Veerasingham Mayooran
Published: June 2021

Extra-axial haemorrhage following epidural anaesthesia is extremely rare. We present the case of an 18-year-old G1P0 woman with Alport syndrome who had a ventouse delivery for failure to progress that was complicated by a postpartum tonic–clonic seizure. Clinically, and confirmed radiologically, the patient was found to have experienced an extra-axial haemorrhage (extradural and subdural haemorrhage) secondary to a cerebrospinal fluid leak caused by a dural puncture during epidural anaesthesia. Differentiating between postdural puncture headache, subdural haemorrhage and extradural haemorrhage can be extremely challenging, but it is important to consider these rare conditions when evaluating patients presenting with postpartum headache and seizure.