Herpes simplex virus type 1 (HSV-1) UL56 gene is involved in viral intraperitoneal pathogenicity to immunocompetent mice

Summary A comparison of the pathogenicity in mice of the recombinant herpes simplex virus type 1 (HSV-1) strain HSV-1-M- LacZ, in which the U_L56 gene has been deleted, was made with its parental strain F, following infection in different mouse strains. The polymerase chain reaction (PCR) technique was used to study the migration of virus DNA in the mouse model. Tissues from adult mice infected intraperitoneally (IP) with one of three HSV-1 strains (F, HFEM or HSV-1-LacZ) were examined for the presence of viral DNA. DNA of the pathogenic strain F was detected in the adrenal glands, spinal cord, brain, liver and pancreas. DNA of HSV-1-M-LacZ was detected in the same tissues. However, DNA of the apathogenic strain HFEM was detected transiently (on days 2 and 3 p.i., but not days 1, 5 or 7), only in the adrenal glands and no viral DNA was detected in any of the other tissues. HSV-1 pathogenic strains injected intraperitoneally into newborn mice (7 days old) killed most of the mice. In the surviving mice viral DNA of the three virus strains was found in peritoneal exudate cells (PEC), adrenal glands, spinal cord, liver and spleen. It was found that HSV-1-M-LacZ, which lacks the U_L56 gene, resembled in pathogenicity to the newborn mice the pathogenic HSV-1 strains F and KOS. The PCR technique was used to trace viral DNA in tissues of the mice which survived HSV-1 infection at 7 weeks of age. Only HSV-1 (KOS) DNA was detected in the pancreas. The brains of these mice did not contain viral DNA. It is suggested that HSV-1 DNA may reside in surviving HSV-1- infected newborn mice in a latent state in nonneural tissues.     

Replication of herpes simplex virus type 1 and 2 in the medulla of the adrenal gland after vaginal infection of mice

Summary After vaginal infections of mice with neuroinvasive strains of herpes simplex virus type 1 and 2 (HSV-1, HSV-2) virus replicates in the epithelium of the vagina, in the paravaginal ganglia, in the spinal cord and finally in the brain and in the adrenal glands. However, viral antigens could be demonstrated only in the medulla of the adrenal glands but not in the cortex, as assessed by immunohistochemistry (IHC). HSV could not be isolated from liver, spleen, uterus, and ovaries. This contrasts to the intraperitoneal (i.p) route of infection with replication in different visceral organs including the adrenal gland's cortex.     

Colonization of adrenal glands and ovaries of mice by variants of HSV 1 and 2

Summary The herpes simplex virus (HSV)-infected mouse model was used to correlate histopathological lesions in adrenal glands and ovaries with the localisation of viral nucleic acids and viral antigens, employing in situ hybridization and immunohistochemistry. In the adrenals, the lesions were mainly restricted to the zona fasciculata and the zona reticularis, sometimes extending to the medulla. In the ovaries, lesions were detected in follicles and in the stroma. During the course of infection, HSV nucleic acids could be detected earlier than HSV proteins. Next to the center of necrotic foci mainly HSV proteins were detected, whereas peripheral cells were found to contain viral nucleic acids. In situ hybridization revealed no proof of HSV latency in either organ. Among HSV-1 and HSV-2 strains of different neurovirulence, only HSV-2 variant ER^– failed to replicate in adrenal glands and ovaries, whereas the neuroinvasive variant ER⁺ showed the same patterns as the HSV-1 strains used.     

Asymptomatic vaginal herpes simplex virus infections in mice: virology and pathohistology

Summary One of the causes of genital tract infections in humans are herpes simplex virus types 1 and 2 (HSV-1, HSV-2). Although primary and recurrent infections can be clinically apparent and in part very serious, many infections are asymptomatic and result only in temporary genital shedding of virus (recurrences). During our investigations of vaginitis, strain IES of HSV-1 produced an asymptomatic infection. Replication in the murine vaginal (vag.) epithelium as well as antibody formation after vag. infection was comparable to those of survivors after infection with highly virulent strains. Titration of liver, spleen, ovaries, adrenal glands, spinal cord, or brain after vag. IES infection revealed no virus, whereas after i.p. infection virus could be demonstrated in many organs examined. Histological examination with a DNA probe (in situ hybridisation), HSV antibodies (immunohistochemistry), and haematoxylin and eosin (HE) staining showed only small focal HSV lesions of the vaginal epithelium in early stages of the infection, never exceeding to the subepithelial tissue. Severe infiltrations and ulcerations after infection with highly virulent strains (17syn⁺, ER^–) could never be demonstrated after IES vag. infection. Identical replication rates of both groups of HSV despite much greater areas of epithelial necrosis with the virulent strains may be explained by the large number of virus inactivating granulocytes induced by the virulent strains, thus inactivating the hypothetical higher virus load.     

Importance of theHpaI-P sequence for herpes simplex virus-1 replication in the adrenal glands

Summary The ability of several strains and recombinants of herpes simplex virus 1 (HSV-1) to proliferate in the adrenal glands and to invade the spinal cord was studied. After intraperitoneal infection, pathogenic HSV-1 strains replicated in the adrenal glands, penetrated the spinal cord and migrated to the brain. The nonpathogenic strain HFEM could not replicate in the adrenal glands, but the recombinant virus MLC1 was able to do so after rescue by reinsertion of theHpaI-P sequence into theBamHI fragment of HFEM DNA. However the recombinant MLC1 virus could not penetrate the spinal cord.The effect of HSV-1 infection on the expression of the cellular genes for multidrug resistance (in the adrenal glands) and proenkephalin A (in the spinal cord) was also studied.     

Herpes simplex virus types 1 and 2 infect the mouse pituitary gland and induce apoptotic cell death

Summary. Herpes simplex virus (HSV) infected the anterior lobe of the pituitary gland resulting in cytopathic changes following intravenous (i.v.) inoculation of male mice. Both HSV type 1 (HSV-1) and type 2 (HSV-2) were isolated from pituitary gland following i.v. infection, but not after intraperitoneal inoculation. HSV-infected pituitary cells were microscopically visible beginning at 24h or 48h following i.v. inoculation and were localized in the anterior pituitary. In both HSV-1 and -2 infections the pituitary lesions were apoptotic, as determined by light and electron microscopy, TUNEL, and DNA gel electrophoresis. However, the pituitary infection does not appear to be life-threatening since pituitary lesions were also observed following i.v. infection with HSV-1 strain –GC which possesses low virulence. These results suggest that the pituitary gland is one of the target organs of HSV infection.     

Reaginic and homocytotropic IgG antibody response ofMastomys natalensis in experimental infections of filarial parasites (Litomosoides carinii,Dipetalonema viteae,Brugia malayi,B. pahangi)

Reaginic and homocytotropic IgG antibodies in sera using passive cutaneous anaphylaxis (PCA) tests and antigen fromLitomosoides carinii were followed inMastomys natalensis, infected withL. carinii, Dipetalonema viteae, Brugia malayi orB. pahangi. Groups of animals with infections of various ages so as to cover a total infection period of up to 300 to 420 days post-infection (p.i.), depending on the species of parasites, were bled at 1- to 3-week intervals over periods of 50–112 days. In addition, intradermal tests were performed on animals infected withL. carinii to detect immediate type hypersensitivity. Reaginic antibodies were usually first detected in the 3rd week after infection. Thereafter, a marked increase of PCA titres was observed in the 4th week p.i. leading to maximum titres 4 weeks after infection withD. viteae andB. pahangi and 6 weeks afterB. malayi infection. Mean maximum titres were between 140 and 1160. Following the peak response, titres decreased markedly until the beginning of patency in infections withD. viteae, B. malayi andB. pahangi whereas a constant course was observed at this time in animals infected withL. carinii. A further rise in PCA titres occurred in all infections around the beginning of patency, resulting in maximum reagin levels inL. carinii infections (mean titre 180) and moderate titres in the other infections. During early patency there was an inverse relationship between microfilaraemia density and levels of reaginic antibodies. However, in the phase of decreasing parasitaemia inL. carinii infected animals, microfilariae counts and PCA titres were directly correlated. Homocytotropic IgG antibodies showed relatively constant PCA titres of about 120 inL. carinii infected Mastomys throughout the observation period. InD. viteae infections they were demonstrated at 30 days p.i., reaching titres of about 140.B. malayi infected animals showed a maximum titre of 140 40 days p.i. Thereafter, titres decreased continuously and homocytotropic IgG antibodies were absent at 110 days p.i. High titres were observed at day 150 but thereafter sera were negative.B. pahangi infected animals showed moderate titres (15) 35 days p.i. Thereafter, antibodies were found at low titres until 115 days p.i. Intradermal reactions inL. carinii infected animals generally increased in size from days 30–60 but decreased when microfilariae appeared in the blood. After 180 days p.i. moderate skin reactions were observed until the end of the experiment 420 days p.i., regardless of whether adult worms could still be found or not.Supported by a Richard Merton Stipendium;     

Different susceptibilities of skin to type 1 and type 2 herpes simplex viruses in newborn rabbits.

Skin infections with type 1 herpes simplex virus (HSV-1) were compared with skin infections with type 2 virus (HSV-2). Five strains each of HSV-1 and HSV-2 were tested by injecting 10(3) 50% tissue culture infective doses of each strain subcutaneously into 1-day-old New Zealand white rabbits. All five strains of HSV- 2 produced severe skin lesions that resulted in wide dissemination of the infection to many organs, paralysis of the hind legs, and finally death. The virus could be isolated frequently from skin lesions, from various organs (liver, lungs, adrenal glands, brain, and eyes), and from circulating leukocytes and plasma. In contrast, all five strains of HSV-1 failed to produce significant skin lesions or dissemination of virus, only half of the skin lesions yielded HSV, and no virus could be isolated from the blood. These results indicate that HSV-1 dose not grow well in the skin of newborn rabbits and fails to disseminate, whereas HSV-2 is dermatotropic and disseminates readily to many organs by hematogenous routes.     

Infectivity of sarcocystis from donkey for horse via sporocysts from dogs

The dog is the final host for sarcosporidia cysts from the oesophagus and diaphragm of donkeys from Sardinia. The prepatent period lasted 9 to 10 days. Sporocysts measured 12.2–13.8×9.2–9.9 m. Infection of a horse with 10⁵ donkey/dog sporocysts increased the rectal temperature to more than 40°C on days 10 and 20 after infection. On day 138 p.i. predominantly immature cysts containing metrocytes were found, especially in the oesophagus. Infection on day 117 p.i. with 2×10⁵ horse/dog sporocysts did not give rise to a temperature increase during the following 21 days.The final host of sarcosporidia cysts from the oesophagus and diaphragm of horses from Sardinia is the dog. The prepatent period lasted 9–10 days. Sporocysts measured 12.2–13.8×9.2–9.9 m. The rise in the rectal temperature of three foals infected with horse/dog sporocysts did not differ from that of the foal infected with donkey/dog sporocysts. In both cases rectal temperature increased to more than 40°C on days 10 and 20 following infection with 10⁵ sporocysts. Because of the occurrence of two temperature peaks following infection, two generations of schizogony are postulated. The presence of a sarcosporidia species occurring in the donkey only is doubtful.This report was supported by a grant of the Deutsche Forschungsgemeinschaft     

Spread of herpes simplex virus (HSV) strains SC16, ANG, ANGpath and its glyC minus and GlyE minus mutants in DBA-2 mice

Herpes simplex virus type 1 (HSV-1) strains SC16, ANG, its pathogenic variant ANGpath and the mutants ANG-pathgC18 glycoprotein C (glyC) negative and ANGpathI2-4 (glyE negative) were compared for their ability to spread in DBA-2 mice after peripheral inoculation. Virus infectivity assay in 9 organs at days 2, 3, 4, 5, 6, and 10 post-infection (p.i.) and morphologic examinations (immunofluorescence, PAP staining) showed the following: SC16, ANG, and ANGpath spread first (days 2-3 p.i.) by haematogenic route to spleen, liver, and adrenal gland. Since day 4 the invasion of the vegetative and peripheral nervous system took place in SC16 and ANGpath-infected mice, followed by virus spread to the spinal cord and brain stem. In ANG-infected mice the invasion of peripheral nervous system was minimal although both ANG as well as ANGpath spread along the axons. In ANG pathC18-infected mice a relatively prolonged viraemic phase (days 2-4 p.i.) represented with foci of virus antigen-containing cells in spleen, liver, and mesenterial connective tissue was accompanied with a low grade invasion of the peripheral nervous system (days 3-4 p.i.). No spread by any route of ANGpathI2-4 was observed after intraperitoneal inoculation. When comparing ANGpath and SC16, the latter seemed slightly more lethal, since ANGpath killed 67.2% of DBA-2 mice which were given 2 X 10(6) PFU/0.1 ml by i.p. route as compared to the 100% lethality of SC16-infected animals.     

Murine cytomegalovirus replication in salivary glands is controlled by both perforin and granzymes during acute infection

The course of mouse cytomegalovirus (MCMV) infection was compared between wild-type and mutant C57BL / 6 (B6) mice deficient in either RAG-2, perforin, granzyme A, granzyme B or combinations thereof at two time points post infection (p. i.). At day 15 p. i., virus titers were similarly elevated in salivary glands of all mutant, but not wild-type B6 mice and undetectable in lung and spleen tissues of any of the mouse strains. Significant pathological alterations were only seen in salivary glands and spleen from RAG2(- / -), but not in those from other mice whereas few inflammatory foci were observed in lung tissues of all mice except B6. At day 30 p. i., elevated virus titers were observed only in salivary glands, lung and spleen from RAG2(- / -), but in none of the other mice, and were accompanied by extended pathological alterations in all three organs. The data extend previous reports on the critical role of NK / CD8(+) T cells in the early control of MCMV infection by showing that both perforin and granzymes A / B contribute to viral elimination in salivary glands; however, neither of the three molecules alone seem to be indispensable for the final control of infection.     

Comparison of the eIF-2α Homologous Proteins of Seven Ranaviruses (Iridoviridae)

The -subunit of the eukaryotic initiation factor 2 (eIF-2) is a key component of the translation machinery of the cell. In response to cellular stress such as viral infections, eIF-2 is phosphorylated by double-stranded RNA-dependent protein kinase (PKR) leading to the inhibition of cellular protein synthesis. The importance of eIF-2 as a regulatory mechanism for protein synthesis is illustrated by the wide variety of strategies employed by viruses to down-regulate PKR. Thus, Vaccinia virus encodes K3L protein, which resembles eIF-2 and acts as a pseudo-substrate inhibitor of PKR. Nucleotide sequencing of the genome of epizootic haematopoietic necrosis virus (EHNV), a member of the genus ranavirus of Iridoviridae, has revealed an eIF-2 equivalent gene. We have cloned and sequenced eIF-2 genes of several iridoviruses of fishes and frogs. The eIF-2 open reading frames and deduced proteins of the iridoviruses investigated exhibit a high degree of homology of both nucleotide and amino acid sequences. At the N-terminus, the iridoviral eIF-2 shows significant homology to the N-termini of cellular initiation factor 2- of various species, to full-length poxviral eIF-2 proteins, and to the S1 domain of ribosomal proteins. Comparison of amino acid sequences of corresponding iridoviral proteins with eIF-2 homologous proteins of poxviruses and eukaryotes has revealed a high conservation of motifs. A phylogenetic analysis of eukaryotic eIF-2 and poxvirus and iridovirus eIF-2 sequences has demonstrated the relationship of these iridoviruses. In order to investigate the role of the eIF-2 equivalent, respective genes have been expressed in prokaryotic and eukaryotic (insect, fish and chicken cell) systems. The iridoviral eIF-2 protein has a molecular weight of 31 kDa and is cytoplasmic. The cellular and viral protein synthesis of iridoviruses is probably regulated by a mechanism similar to that of Vaccinia virus. Frog-virus 3, the type species of the genus ranavirus of Iridoviridae, has a unique translational efficiency and, moreover, down-regulates the cellular protein synthesis of infected cells.     

Oral bromovinyldeoxyuridine therapy for herpes simplex and varicella-zoster virus infections in severely immunosuppressed patients: a preliminary clinical trial

Twenty-five patients with haematological diseases were treated orally with the highly potent and selective anti-herpes agent, bromovinyldeoxyuridine (BVDU), in a dosage of 7.5 mg/kg/day (divided over three or four doses a day) for 5 days for an intercurrent mucocutaneous herpesvirus infection. Of these 25 patients, 8 were severely granulocytopenic at the time of the viral infection, and 12 recently had undergone bone-marrow transplantation; 5 were under cytotoxic therapy for a lymphoproliferative disorder; 13 had herpes simplex virus type 1 (HSV-1); 1 had herpes simplex virus type 2 (HSV-2); and 11 had varicella-zoster virus (VZV) infection. In all but two patients, BVDU arrested progression of the HSV or VZV infection within 1-2 days after treatment was started. One of the two patients who failed to respond to BVDU had an HSV-2 infection. The other had an HSV-1 infection, which was highly sensitive to BVDU in vitro; BVDU may have failed in this patient because of incomplete drug intake or profuse diarrhoea, or both. The results of this preliminary uncontrolled clinical trial suggest that BVDU may be an effective and safe drug for the oral treatment of HSV-1 and VZV infections in severely immunosuppressed patients.     

Inter-relationships between pituitary-adrenal hormones and catecholamines during a 6-day Nordic ski race

Summary The aim of the study was to investigate the inter-relationships between pituitary-adrenal hormones and catecholamines during a prolonged competition over 6 days. Plasma adrenocorticotropic hormone (ACTH), cortisol (C), -endorphin (EP), free and sulphated adrenaline (A) and noradrenaline (NA) were measured in 11 volunteer male subjects during a national Nordic-ski race (323 km). Blood samples were obtained before the competition in the evening as control (D₀), and before and after each day's racing (D₁–D₆). The mean daily heart rate (f _c) was calculated fromf _c values recorded every minute during the race. The results showed the following: changes in meanf _c [from 147 (SEM 3) to 156 (SEM 3) beats · min^–1 according to the day] were not significant during the race. Diurnal variations in ACTH, EP and C were no longer apparent after the race: evening levels were higher than their respective D₀ values during the race, except on D₃ when there was a lack of response to exercise in the three hormones. Unlike ACTH and EP, pre- and postexercise C values on D₁ and D₂ were higher than those on the subsequent days (P<0.001). In contrast, there was a progressive accumulation of A and NA in pre-and postrace concentrations which reached a plateau in about 4 days. Positive correlations between exercise responses in ACTH, C and EP were found especially on D₃ and D₆ (P<0.001) but there were no significant correlations between catecholamines and the other three hormones. Thus, prolonged competition over 6 days evoked different control mechanisms for hormones of the pituitary-adrenal axis and catecholamines. A sustained catecholamine release and sympathetic activation induced a progressive NA and A accumulation during the race. In contrast, the lack of a response to exercise in ACTH, EP and C on D₃ suggested a dissociated central command for pituitary axis hormones and sympathetic adrenal activation. On the following days, the response to a lack of exercise, in spite of ACTH stimulation, may have reflected an adaptation of adrenal glands to prolonged stress.     

Colonization of adrenal glands and ovaries of mice by HSV-2 variants

Summary HSV-2 strain ER was shown to consist of variants with different pathogenic phenotype: Variant ER⁺ replicates to high titers in the adrenal glands and the ovaries but much less in the spleen; the testes were not colonized. Er⁺ migrates to the spinal ganglia and is highly neuroinvasive after i.p. inoculation. Variant ER^– replicates 100–1,000 fold less in the adrenal glands and the ovaries, but proceeds to the spinal ganglia without invading the CNS. However, both variants are highly neuropathogenic after direct i.c. injection. We conclude that neuropathogenicity, neuroinvasiveness and the ability to replicate in the adrenal glands as well as ovaries are each determined by different sets of genes. Replication in mouse embryo fibroblasts—but not in Vero and adreno cortical carcinoma Y1 cells—is different for both strains. Also the adsorption capacity to cultured cells differs as shown by addition of D.S.500. ER^– is eliminated from the blood stream more quickly than ER⁺. Finally,C. parvum reduces the rate of replication of both variants in the adrenals and the ovaries. It is concluded that different adsorption and replication rates of variants ER⁺ and ER^– in cell types critical for spread of HSV are responsible for the different pathobiological properties.     

Involvement of actin-containing microfilaments in HSV-induced cytopathology and the influence of inhibitors of glycosylation

Summary Two and a half hours after infection with a high dose of different strains of HSV-1 which induce rounding of cells, breakdown of actin containing microfilaments can be observed. At the periphery of the cell, actin containing knob-like protuberances were visible. Later on, actin seems to be located exclusively on the surface of cells. Observations were done by immunofluorescence microscopy, scanning electron-microscopy and immunoperoxidase staining of ultrathin sections. The envelope of HSV appears to be stained by anti-actin. Strain IES produces rounding of cells at a high dose of infection before fusion proceeds at 37°C. Similar alterations were not observed with the fusing strains MP and HFEM. Incubation of infected cells at 39°C revealed strain dependent differences of the fusion activity. At 41°C no fusion from within of cells but only rounding was detectable. Application of tunicamycin resulted in complete inhibition of fusion by all strains. The fusion activity of some strains of HSV-1 (ANG, HFEM, and MP) was not inhibited by addition of 2-deoxy-D-glucose and 2-fluoro-deoxy-D-glucose. A variant from strain MP could be isolated, which is sensitive to the effects of 2-deoxy-D-glucose. Inhibitors of processing of glycoproteins did not affect fusion of cells.With 8 FiguresIn part presented at the meeting of the DGMH, Würzburg, March 17–19, 1983.     

Sympathoadrenal system under conditions of increased left and right ventricular afterload

Adrenergic plexuses in the myocardium and adrenal medulla were studied histochemically under conditions of increased left or right ventricular afterload. Under conditions of high afterload not accompanied by heart failure the density of sympathetic myocardial innervation remained unchanged in the loaded ventricle, but increased in the intact ventricle. Comparison of the state of the sympathoadrenal system under conditions of increased afterload complicated or uncomplicated by heart failure revealed common prognostically unfavorable changes: sharp decrease in the density of adrenergic nerve plexuses in the ventricular myocardium and activation of adrenal chromaffin cells.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 11, pp. 597–600, November, 2004     

Anti-Dopamine Antibodies: Effects on Behavior in an “Open Field,” Pain Sensitivity, CNS Monoamine Content, and Functional Activity of Immunocytes in C57Bl/6 Mice

Single i.p. doses of anti-dopamine antibodies were given to C57Bl/6 mice. This resulted in inhibition of motor activity in a large proportion of the animals in the open field test, which lasted five days. Hyperalgesia, detected 1.5 h and 1 day after doses of antibody, was replaced by analgesia on day 5. There was a sharp reduction in the levels of dopamine and its metabolites in the cerebral cortex at 1 and 5 days; the serotonin level was increased 1 day after doses of antibody, and was significantly decreased at 5 days. There was no effect on cells of the immune system. The possible mechanisms of the neurotropic action of these antibodies are discussed.     

Localization of herpes simplex virus type 1 in sebaceous glands of mice

Summary The distribution of HSV-1 during the development of zosteriform skin lesions in SCID mice was analyzed by immunofluorescence and electron microscopy. The virus initially appeared within certain keratinocytes, sometimes surrounded by keratinocytes whose surfaces were also positive for the antigens, in the lower epidermal layers including the hair follicles, and then extended upward to the entire epidermis and downward to the sebaceous glands 1–2 days later, when no macroscopic skin lesion was seen. The affected epidermal cells subsequently degenerated and lost their viral antigens within a day, when the zosteriform lesion then became evident. This was followed by a degeneration of the dermis. The sebaceous glands eventually degenerated in 10 days, but some glands in the necrotic skin areas preferentially retained HSV-1. The horizontal spread of the virus in the epidermis beyond the first invaded dermatome occurred much later. In mice passively immunized with specific immune serum, viral antigens were observed even 20 days after the infection in sebaceous glands in necrotized areas. Therefore, HSV-1 appears to spread first via the extracellular fluid among the keratinocytes after being shed from nerve endings, and then produces a successive degeneration of the affected keratinocytes which may prevent any further extension of horizontal viral spread. The pilosebaceous apparatus is possibly acting as a site not only for the replication of HSV-1 with a delayed cytopathic effect, but also as an area that is temporarily sheltered from host defense mechanisms.     

Variable antifungal susceptibility of wild-typeCandida albicans phenotypes from neutropenic hosts

The aim of the present study was to investigate the relationship between phenotypes ofCandida albicans strains isolated from clinical specimens and susceptibility of the strains to two antifungal agents, itraconazole and fluconazole. Oropharyngeal, gastrointestinal tract, and urogenital tract specimens were collected from 131 neutropenic patients withCandida infection who had received no previous prophylactic treatment. The most frequent species isolated wasCandida albicans, followed byCandida glabrata,Candida tropicalis, Candida krusei, andCandida parapsilosis. Each of the 44Candida albicans strains recovered was found to express one of four phenotypes: smooth, irregular, fuzzy or stipple. Mean minimum inhibitory concentrations (MICs) of itraconazole and fluconazole as determined by the microdilution method and the E-test were consistently higher forCandida albicans strains expressing the stipple phenotype. The mean MICs for the four phenotypes of theCandida albicans strains ranged between 0.35 g/ml and 2.41 g/ml for itraconazole and 2.78 g/ml and 5.2 g/ml for fluconazole. Antifungal susceptibility of the stipple phenotype requires careful appraisal, especially in patients clinically unresponsive to azole chemotherapy or in cases of life-threatening, deepseatedCandida infections.