H. P. Chu

University of California, Davis

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Y. C. Zee

University of California, San Diego

P. K. Uppal

Government of Pakistan

Gyorgy Snell

VIR Biotechnology (United States)

RJ Wells

UNSW Sydney

David C. Bolton

New York State Office for People With Developmental Disabilities

R.W. Horne

University of East Anglia

Barry C. Kelly

Simon Fraser University

G. C. Schild

IP Australia

D. M. BERRY

Eli Lilly (United States)

D. J. Alexander

Animal and Plant Health Agency

Cooperative Institutions

University of California, Davis

University of Cambridge

University of California, San Francisco

Central Veterinary Research Laboratory

Cambridge School

Cornell University

University of California, San Diego

National Chung Hsing University

University of California, Berkeley

VIR Biotechnology (United States)

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Enzyme-linked immunosorbent assay for the detection of antibodies to bovine viral diarrhea virus in bovine sera

Veterinary Microbiology (1985)

H. P. Chu Y. C. Zee Alex Ardans Kang Dai

Pestivirus

10.1016/0378-1135(85)90003-3

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Citations (46)

Attachment of Mycoplasma gallisepticum to the tracheal epithelium of fowls

Research in Veterinary Science (1977)

P. K. Uppal H. P. Chu

Fowl

10.1016/s0034-5288(18)33298-3

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Citations (24)

The Egg-Yolk Reaction of Aerobic Sporing Bacilli

Journal of General Microbiology (1948)

Charles McGaughey H. P. Chu

SUMMARY: Among a large number of strains of aerobic sporing bacilli only Bacillus cereus, B. mycoides and, to a lesser extent, B. anthracis were able to produce turbidity and formation of a curd in saline extract of egg-yolk. None of the other species tested, namely, B. alvei, B. alcalophilus, B. brevis, B. carotarum, B. circulans, B. coagulans, B. fusiformis, B. licheniformis, B. macerans, B. megatherium, B. pumilus, B. polymyxa, B. orpheus, B. repens and B. subtilis caused any opalescence in the yolk medium. The yolk reaction was due to the action of phospholipinase produced by the organisms. As in the case of Cl. welchii α-toxin, the yolk curd-forming activity of B. cereus and B. mycoides also was associated with haemolytic activity. The substances responsible for these activities appear to be similar, and may be identical. The yolk reaction has proved useful for the rapid identification of B. cereus, as it is more specific than any of the other distinguishing tests hitherto employed. The three positive organisms, B. cereus, B. mycoides and B. anthracis, have been considered by previous workers on the grounds of morphology and antigenic structure to be closely related.

Cereus

Yolk

Bacillus anthracis

Mycoplasma mycoides

Group B

Bacillus (shape)

10.1099/00221287-2-3-334

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Citations (70)

A laboratory handbook on diagnosis of poultry diseases.

H. P. Chu

Source

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Citations (7)

ELECTRON MICROSCOPY OF MYCOPLASMA GALLISEPTICUM AND MYCOPLASMA MYCOIDES USING THE NEGATIVE STAINING TECHNIQUE AND THEIR COMPARISON WITH MYXOVIRUS

Annals of the New York Academy of Sciences (1967)

H. P. Chu R.W. Horne

Mycoplasma mycoides

Animal health

Annals

10.1111/j.1749-6632.1967.tb27658.x

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Citations (35)

The structure of infectious bronchitis virus

Virology (1964)

D. M. BERRY J.G. Cruickshank H. P. Chu RJ Wells

Negative stain

10.1016/0042-6822(64)90263-6

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Citations (90)

Evaluation of the critical parameters of a sensitive ELISA test using purified infectious bovine rhinotracheitis virus antigens

Veterinary Microbiology (1981)

David C. Bolton H. P. Chu Alexander A. Ardans Barry C. Kelly Y. C. Zee

Conjugate

Dilution

10.1016/0378-1135(81)90020-1

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Citations (38)

Variation of Bacillus anthracis with special reference to the non-capsulated avirulent variant

Epidemiology and Infection (1952)

H. P. Chu

Normal virulent B. anthracis all possess the genetical potentiality of producing capsules, but the capsule is only produced in vivo or under special cultural conditions suitable for capsule formation, especially in the presence of CO 2 . During multiplication the potentially capsulated cells regularly produce a small number of a stable non-capsulated avirulent variant. All laboratory stock cultures of B. anthracis examined were found to contain from 0·14 to 32·4% of this avirulent variant. The variant has also been demonstrated in hair and wool from anthrax endemic areas, which suggests that the dissociation may also occur in nature. Both the normal potentially capsulated cell and the variant incapable of producing capsules grow on plain agar in air as rough colonies with apparently non-capsulated cells. But when they are grown on serum agar in the presence of CO 2 , the normal potentially capsulated cell gives rise to a smooth mucoid colony with fully capsulated cells, while the variant still produces a rough colony with non-capsulated cells. If we regard the smooth mucoid colony produced by normal virulent B. anthracis on serum agar in CO 2 as the normal colony form of B. anthracis , then the dissociation of the avirulent non-capsulated variant with the rough colony form falls in line with the usual S-R dissociation of other bacteria. The more widely known variation of B. anthracis , which had long been held as an exception to the usual S-R variation of other bacteria, refers to colonies grown on plain agar in air. This variation is different from the one just described and is not so clear-cut and significant. Its underlying cause is not quite clear except that the chain length of the growth appears to play some part. A summarized picture showing the whole range of variation in colony appearance and cell structure of B. anthracis is presented.

Bacillus anthracis

10.1017/s0022172400019720

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Citations (17)

An Electron-Microscope Study Of The Trachea Of The Fowl Infected With Avian Infectious Bronchitis Virus

Journal of Medical Microbiology (1970)

P. K. Uppal H. P. Chu

SUMMARY Fowls were infected with avian-IBV and, subsequently, their tracheas were sectioned and examined in the electron microscope. The lining epithelial cells showed extensive loss of cilia, degeneration of microvilli, swelling of mitochondria, increased amount of endoplasmic reticulum and of other intracellular membranes, and the presence of electron-dense areas in the cytoplasm. Virus particles were first observed about 12 hr after infection within the electrondense areas and within spaces between the membranes of the endoplasmic reticulum. By 48–72 hr they were considerably more numerous and were present mainly within cisternae and vesicles formed from the membranes of the endoplasmic reticulum. There was little evidence of budding. The mature virus particle had a mean diameter of 81±1 nm and possessed both inner and outer electron-dense coats or shells separated by an electron-transparent layer. Virus particles grown in the embryonated hen egg and harvested from the allantoic fluid had a similar size and structure.

Embryonated

Fowl

10.1099/00222615-3-4-643

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Citations (19)

The Lecithinase of Bacillus cereus and its Comparison with Clostridium welchii -toxin

Journal of General Microbiology (1949)

H. P. Chu

Summary: Bacillus cereus and B. mycoides produce lecithinases which split lecithin into phosphorylcholine and a diglyceride in the same way as the lecithinase (α-toxin) of Clostridium welchii. These enzymes also possess most of the biological activities associated with Cl. welchii α-toxin, e.g. produce the Nagler reaction and the egg-yolk reaction, lyse red blood cells, and are dermonecrotizing and lethal. The enzymes are activated by Ca and Mg ions, but inhibited by Na, K, NH4 ferric and Al ions. Optimal enzyme activity requires the presence of Ca ions within a narrow range of concentration of 1–4 × 10−3 m. It is interesting that at this concentration of Ca ion lecithin flocculates most readily from its emulsion. The enzyme thus seems to have a maximal affinity for lecithin when the latter adsorbs an optimal amount of Ca ion in reaching its isoelectric point. Like the Cl. welchii lecithinase, the B. cereus lecithinase is fairly resistant to heat. The lysis of red blood cells and the hydrolysis of free lecithin by B. cerBus lecithinase was strongly inhibited by normal sera of all the animals tested. But when lecithin was bound in egg-yolk lipoproteins, its hydrolysis by the enzyme was unaffected by normal serum. Specific serum, on the other hand, was capable of inhibiting the hydrolysis of both free lecithin and protein-bound lecithin. The B. cereus and B. mycoides lecithinases are immunologically related, but they are not so related to Cl. welchii lecithinase.

Lecithinase

Cereus

10.1099/00221287-3-2-255

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Citations (94)