The Source of Biliary Infections Associated with T-Tube Drainage

The purpose of this study was to determine the source of organisms responsible for biliary infection associated with T-tube placement. Two groups of patients who had had T-tubes placed following common bile duct exploration were studied. In one group of 34 patients, bacterial cultures were taken daily from the drainage bag and the lumen of the T-tube. In the second group of patients, paired daily bacterial cultures were taken from the T-tube lumen and the skin tract surrounding the T-tube. Results of the first group showed the drainage bag to be the initial site of infection in seven cases, with “descending” infection from the patient's skin occurring in 27 cases, 14 in whom the organism was initially present in the bile while in the other 13 the organism appeared later. In the second group, of 32 isolates only five were found extraluminally before they appeared within the lumen, these five being all Staphylococcus epidermidis. Thus the majority of bile infections occurring after T-tube placement were found to originate from the patient's own biliary tree or skin.

Clinical features of clostridial bacteremia: a review from a rural area

Blood samples, which were obtained from patients who lived in a rural area with approximately 500 acute-care hospital beds, were cultured from 1990 through 1997. We retrospectively reviewed the blood cultures that yielded Clostridium species (74 [0.12%] of 63,296 cultures). These were obtained from 46 different hospitalized patients (incidents per hospital, 0.03%). The source of the Clostridium species was a gastrointestinal site in 24 patients (52.2%). The most frequently identified Clostridium species was Clostridium perfringens (in 10 [21.7%] of patients), followed by Clostridium septicum (in 9 [19.6%]). Thirty-one patients (67.4%) were aged > or =65 years, 13 patients (28.3%) had diabetes mellitus, and underlying malignancy was present in 22 patients (47.8%). The mortality rate of patients whose condition had been managed surgically was 33%; for those patients whose conditions required medical management, the mortality rate was 58%. Clostridium bacteremia in these patients usually had a gastrointestinal source, it often occurred in patients with serious underlying medical conditions, and it rarely was the result of traumatic farm accidents.

Chronic sternal wound infection and endocarditis with Coxiella burnetii

Chronic Q fever is most commonly associated with culture-negative endocarditis and less frequently with infection of vascular grafts, infection of aneurysms, hepatitis, pulmonary disease, osteomyelitis, and neurological abnormalities. We report a case of chronic sternal wound infection, polyclonal gammopathy, and mixed cryoglobulinemia in which Q fever endocarditis was subsequently diagnosed. Polymerase chain reaction analysis of the wound tissue was positive for Coxiella burnetii DNA, and treatment of the endocarditis resulted in prompt healing of the wound. Chronic Q fever can occur without epidemiological risk factors for C. burnetii exposure and can produce multisystem inflammatory dysfunction, aberrations of the immune system, and persistent wound infections.

Coinfection with Babesia microti and Borrelia burgdorferi in a western Wisconsin resident

A 68-year-old woman, who had not traveled outside of western Wisconsin, was hospitalized after 4 weeks of chills, fevers, myalgias, neuralgias in her right arm, and pain in the right upper quadrant of her abdomen. Physical examination revealed hepatosplenomegaly, and laboratory studies showed anemia, thrombocytopenia, increased aspartate transaminase level, and microscopic hematuria. Wright's stain of a blood smear revealed intraerythrocytic organisms consistent with Babesia species. A polymerase chain reaction of whole blood specimens along with an increased serologic titer confirmed the diagnosis of Babesia microti. Indirect immunofluorescent antibody serology and Western blot analysis revealed a simultaneous infection with Borrelia burgdorferi. Coinfection with B. microti and B. burgdorferi may occur in endemic areas where both organisms are carried by the same tick vector, Ixodes scapularis. The intensity and duration of illness seem to be greatest in patients with concurrent infection.

Performance measurement in pneumonia care: beyond report cards

OBJECTIVE

To compare the medical management of bacteremic pneumococcal pneumonia at a university-based and a community-based teaching hospital and evaluate strategies for performance measurement and subsequent improvement.

DESIGN

We conducted a retrospective cohort study involving a 450-bed university hospital in the inner city and a 400-bed private hospital in a rural community.

MATERIAL AND METHODS

The medical records of all adults with bacteremic pneumococcal pneumonia admitted to a university and a community hospital during a 5-year period were reviewed. Information about patient age, sex, underlying medical condition, severity of disease, health-care insurance, management, and outcome was collected and analyzed.

RESULTS

Patients at the two hospitals were similar in underlying illnesses and severity of disease. In comparison with the community hospital, resource expenditure was greater at the university hospital, where all 11 identified diagnostic measures and treatment resources were used more often. This difference was statistically significant for sputum cultures, all cultures, and lumbar punctures. Despite the greater intensity of care, in-hospital mortality was higher at the university hospital (26%) than at the community hospital (12%) (P>0.1).

CONCLUSION

The outcome of bacteremic pneumococcal pneumonia did not differ significantly at a university hospital in comparison with a community teaching hospital, even though resource expenditure at the university hospital was greater. Our findings suggest that hospital "report cards" based solely on outcome comparisons provide inadequate information. In contrast, examination of variations in profiles of resource utilization can detect important differences in hospitals and can be used to guide continuous quality improvement efforts and ultimately improve hospital care.

Ceftriaxone compared with doxycycline for the treatment of acute disseminated Lyme disease

BACKGROUND

Localized Lyme disease, manifested by erythema migrans, is usually treated with oral doxycycline or amoxicillin. Whether acute disseminated Borrelia burgdorferi infection should be treated differently from localized infection is unknown.

METHODS

We conducted a prospective, open-label, randomized, multicenter study comparing parenteral ceftriaxone (2 g once daily for 14 days) with oral doxycycline (100 mg twice daily for 21 days) in patients with acute disseminated B. burgdorferi infection but without meningitis. The erythema migrans skin lesion was required for study entry, and disseminated disease had to be indicated by either multiple erythema migrans lesions or objective evidence of organ involvement.

RESULTS

Of 140 patients enrolled, 133 had multiple erythema migrans lesions. Both treatments were highly effective. Rates of clinical cure at the last evaluation were similar among the patients treated with ceftriaxone (85 percent) and those treated with doxycycline (88 percent); treatment was considered to have failed in only one patient in each group. Among patients whose infections were cured, 18 of 67 patients in the ceftriaxone group (27 percent) reported one or more residual symptoms at the last follow-up visit, as did 10 of 71 patients in the doxycycline group (14 percent, P > or = 0.05). Mild arthralgia was the most common persistent symptom. Both regimens were well tolerated; only four patients (6 percent) in each group withdrew because of adverse events.

CONCLUSIONS

In patients with acute disseminated Lyme disease but without meningitis, oral doxycycline and parenterally administered ceftriaxone were equally effective in preventing the late manifestations of disease.

AIDS-related lymphomas with neurologic manifestations

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Clinical comparison of borreliacidal-antibody test with indirect immunofluorescence and enzyme-linked immunosorbent assays for diagnosis of Lyme disease

OBJECTIVE

To compare the clinical results with the borreliacidal-antibody test (BAT) and two standard screening serologic tests for Lyme disease (LD)-the indirect immunofluorescence assay (IFA) and the enzyme-linked immunosorbent assay (ELISA).

DESIGN

The medical records of patients from an endemic LD area, who had been serologically tested during the summer of 1992, were retrospectively categorized by clinical diagnoses without results of serologic tests. Serologic testing, which included control serum samples from patients from a nonendemic LD area, was performed in a blinded fashion, and the results were compared with the clinical categories.

MATERIAL AND METHODS

Medical records of 307 patients who had been serologically tested for LD were reviewed. We found untreated, active LD in 43 patients (early-localized LD, 21; early-disseminated LD, 14; and late-disseminated LD, 8) and treated LD in 33. Non-LD cases were categorized into acute or chronic conditions of unknown or known cause.

RESULTS

Overall, the BAT had a sensitivity of 11% in active LD and did not correlate with results of other conventional surface antibody assays. The IFA and ELISA were more sensitive (67 to 93%), but false-positive results frequently were noted (20 to 40%) in acute and chronic non-LD inflammatory conditions. The specificity of the BAT, IFA, and ELISA in the control group was 96%, 93%, and 97%, respectively.

CONCLUSION

Until the sensitivity, as measured by prospective clinical studies, is improved without loss of specificity, the BAT should not be used clinically for the diagnosis of LD. Suspected cases of LD with atypical clinical manifestations should have positive ELISA and IFA results confirmed with a standardized immunoblot assay.

Subclavian hemodialysis catheter infections: a prospective, randomized trial of an attachable silver-impregnated cuff for prevention of catheter-related infections

OBJECTIVE

To determine if an attachable silver-impregnated cuff is effective in reducing subclavian hemodialysis catheter-related infections.

DESIGN

Prospective, randomized, nonblinded study.

SETTING

Community teaching hospital.

PATIENTS

One hundred one acute and chronic renal failure patients requiring subclavian venipuncture and catheterization. After randomization, 47 patients underwent subclavian catheterization with a silver-impregnated cuff (Ag-CC), and 54 patients had routine catheter (RC) placements.

MEASUREMENTS

Multiple presumed predictor variables for catheter-related infections, exit site infection rate, bacteremia rates, and semiquantitative cultures of all catheters.

Babesiosis in Wisconsin: a potentially fatal disease

Babesiosis is emerging as an important tick-borne zoonosis in the United States. Most reported cases of this parasitic disease have been acquired in the Northeast. To date, only two clinical cases of Babesia microti infection acquired in the upper Midwest have been described. We report eight more cases. Most if not all of the 10 total cases probably were acquired in northwestern Wisconsin. Three cases (30% of 10) we now report were fatal and occurred in elderly patients (65-75 years old) who died after complicated hospital courses. One patient probably had had a latent Babesia infection that activated because of immunosuppression attributable to high-dose corticosteroid therapy and to splenic infarctions caused by cholesterol emboli. All three fatal cases were diagnosed incidentally and highlight the importance of considering the diagnosis of babesiosis in febrile patients who have been in babesiosis-endemic areas; examining their blood smears carefully; and treating promptly with clindamycin and quinine, and, if indicated, exchange transfusion. Medical personnel should be knowledgeable about this zoonosis, which is not limited to the northeastern United States, and is potentially serious, sometimes fatal.

Pseudomonas aeruginosa infections of intact skin

Pseudomonas aeruginosa infections of healthy skin are uncommon. We report four cases of P. aeruginosa infections of intact skin. These cases illustrate the clinical spectrum of these cutaneous infections: localized, mild epidermal infections (the green nail syndrome and webbed space infections), moderately serious infections (cutaneous folliculitis and otitis externa), and, in immunocompromised patients, extremely serious infections (malignant otitis externa, perirectal infection, and ecthyma gangrenosum).

Subcutaneous alternariosis of the foot in a patient on corticosteroids

To the authors' knowledge, this is the first reported case of alternariosis involving the subcutaneous tissues of the foot. Podiatrists are likely to see more of this condition and other unusual fungi causing deep foot infections in the future because of the increasing population of immunocompromised patients.

In vitro susceptibilities of Borrelia burgdorferi to five oral cephalosporins and ceftriaxone

We determined the in vitro susceptibilities of eight Borrelia burgdorferi isolates to five oral cephalosporins. MICs for B. burgdorferi 297 were 23 micrograms/ml (cephalexin), 45 micrograms/ml (cefadroxil), 91 micrograms/ml (cefaclor), 0.13 microgram/ml (cefuroxime), 0.8 microgram/ml (cefixime), and 0.02 microgram/ml (ceftriaxone). When B. burgdorferi isolates were exposed to concentrations twice the MIC of cefuroxime, cefixime, or ceftriaxone, at least 72 h of incubation was required to kill 99% of the organisms.

Survey for Ixodes spp. and Borrelia burgdorferi in southeastern Wisconsin and northeastern Illinois

Forested areas adjacent to Milwaukee, Wis., and Chicago, Ill., were investigated for rodents and ticks infected with Borrelia burgdorferi, the causative agent of Lyme disease. White-footed mice (Peromyscus leucopus or Peromyscus maniculatus), meadow voles (Microtus pennsylvanicus), and eastern chipmunks (Tamias striatus) were captured; and specimens from these animals were cultured for B. burgdorferi to define whether the midwestern Lyme disease area currently encompasses these large metropolitan centers. During 1988, B. burgdorferi was successfully cultured from the tissues of two M. pennyslvanicus voles captured from the Chicago area. However, no Ixodes spp. ticks were captured. None of 274 animals captured from sites I3 and 12 additional sites in Wisconsin and Illinois during the summer of 1989 were infected with B. burgdorferi or Ixodes spp. In addition, no ticks were recovered when the underbrush in 11 contiguous areas was flagged. Apparently, B. burgdorferi is rarely found in these areas because of the absence of the appropriate tick vectors. Further studies are needed to monitor the dispersal of B. burgdorferi-infected Ixodes dammini into this heavily populated midwestern region.

Effects of bovine serum albumin on the ability of Barbour-Stoenner-Kelly medium to detect Borrelia burgdorferi

The ability of decreasing inocula of Borrelia burgdorferi to grow in otherwise identical Barbour-Stoenner-Kelly (BSK) media containing different lots of bovine serum albumin (fraction V) was determined. These media differed significantly in ability to detect B. burgdorferi. Some BSK media required inocula of 2 x 10(5) organisms per ml for detection, while other media could stimulate growth after inoculation with less than 2 organisms per ml. In addition, organisms from the less sensitive BSK media were thinner, longer, and less tightly coiled. The endpoint dilutions of indirect fluorescent-antibody titers, especially immunoglobulin M, exhibited up to 16-fold decreases, and both immunoglobulin G and M titers were more difficult to interpret with diagnostic slides prepared from some longer, thinner B. burgdorferi. These results demonstrate that, when performing laboratory investigations which rely on B. burgdorferi, it is essential that the quality of the BSK medium be determined.

Efficacy of the urinary bladder for isolation of Borrelia burgdorferi from naturally infected, wild Peromyscus leucopus

The efficacy of culturing urinary bladder tissue for Borrelia burgdorferi from naturally infected, wild Peromyscus leucopus mice was determined. The urinary bladder cultures were as efficient as spleen, kidney, and blood tissue cultures. The rapid B. burgdorferi isolation (mean, 6 days) from mouse urinary bladders should aid in defining new Lyme disease foci.

Borrelia burgdorferi infection surrounding La Crosse, Wis

This investigation defined the extent of Borrelia burgdorferi infection surrounding La Crosse, Wis. White-footed mice, Peromyscus leucopus or P. maniculatis, were captured from sites in Wisconsin, Minnesota, and Iowa and cultured for B. burgdorferi to define the local boundaries of the midwestern Lyme disease area. All foci of B. burgdorferi infection (N1, N2, N3, and N4) were located north of interstate highway 90 except focus S2, which was south of the highway near Fort McCoy, Wis. The interstate highway may have been a barrier to deer movement which slowed the southward dispersal of Ixodes dammini. B. burgdorferi was isolated from 12 (63%) of the mice captured from site N4, which was adjacent to the western border of Fort McCoy. Unexpectedly, no B. burgdorferi-infected mice were isolated at site N0, located north of interstate highway 90 and enclosed by areas in which B. burgdorferi infection is endemic. This site is surrounded by natural barriers which may have slowed the spread of I. dammini by deer. The Wisconsin area in which B. burgdorferi is endemic should now include the surrounding area north of interstate highway 90 west from Fort McCoy to the Mississippi River. Additional studies are needed to define the rapidity, limits, and means of I. dammini dispersal into southern Wisconsin.

Enterococcal bacteremia: clinical features, the risk of endocarditis, and management

The enterococci, members of the group D streptococci and the predominant aerobic streptococci of the gastrointestinal and female genital tracts, have long been recognized as significant pathogens in infective endocarditis. Over the past 2 decades, enterococci have become increasingly important nosocomial pathogens, related to their intrinsic resistance to many antibiotics, especially the cephalosporins, and the greatly increased use of antimicrobial therapy in hospitals. Recent reports have documented an alarming increase in the frequency of high-level resistance to aminoglyclosides, and strains resistant to ampicillin by production of a beta-lactamase and to vancomycin have now been encountered. We have reviewed the clinical features and course of 153 cases of enterococcal bacteremia occurring in a university hospital over the 14-year period, 1970 to 1983, 1) to understand better the importance of enterococci as human pathogens, 2) to identify the clinical features of enterococcal bacteremia, 3) to isolate those findings that help to identify associated endocarditis, and 4) to develop guidelines for more effective antimicrobial therapy of bacteremic enterococcal infections. The annual incidence of enterococcal bacteremia in our center rose three-fold over the period reviewed. In 65 cases (42%), bacteremia was polymicrobial, caused by Enterococcus and at least 1 other microorganism, usually an aerobic gram-negative bacillus. Most bacteremias were nosocomial and derived from infections of the urinary tract (29 cases), intravenous catheters (24 cases), intra-abdominal infections or surgical wounds (46 cases), burn wounds (25 cases), or cholangitis (21 cases); only 1 case originated from a pneumonia. Endocarditis was identified in association with 12 of 35 community-acquired bacteremias, but only 1 of 118 bacteremias acquired in the hospital (P less than .001). Endocarditis was also significantly associated with pre-existent valvular heart disease and cryptogenic bacteremia, and was negatively associated with polymicrobial enterococcal bacteremia (no endocarditis in 65 cases, P less than .001). Isolated enterococcal bacteremia produced an indolent infection rarely associated with shock (3 of 64 cases evaluated, all cases due to valve destruction by endocarditis); conversely, with polymicrobial enterococcal bacteremia, primarily with gram-negative bacilli, shock or disseminated intravascular coagulation developed in 50% of cases (P less than .001).(ABSTRACT TRUNCATED AT 400 WORDS)

Cryptosporidiosis

In the United States, the four groups at high risk of cryptosporidiosis are animal handlers, foreign travelers, children in day care centers and immunocompromised patients, including those with acquired immunodeficiency syndrome. In immunocompetent patients, the sporadic diarrheal illness is self-limited. Diagnosis is made by the identification of Cryptosporidium oocysts in stool specimens, but these parasites are easily overlooked and may be confused with yeast. At present, there is no specific therapy for this infection.

Enumeration and characterization of Aeromonas hydrophila and Aeromonas caviae isolated from grocery store produce

Starch-ampicillin agar was used to quantitatively isolate Aeromonas sp. from retail grocery store produce. All produce sampled, including parsley, spinach, celery, alfalfa sprouts, broccoli, and lettuce, contained Aeromonas sp. In most instances, the count of Aeromonas sp. increased 10- to 1,000-fold during 2 weeks of storage at 5 degrees C. Eleven (92%) of 12 kinds of produce yielded cytotoxic Aeromonas sp. Identification as Aeromonas hydrophila was the strongest indicator of cytotoxicity, and all 29 (100%) A. hydrophila isolates and 1 (6%) of 16 A. caviae isolates were cytotoxic. Twenty-seven (90%) of 30 cytotoxic Aeromonas sp. strains produced hemolysins. Strong correlations were also noted between ability to produce cytotoxin and positive Voges-Proskauer, lysine decarboxylase, and sorbitol fermentation reactions. It appears that grocery store produce is a potentially significant source of cytotoxic Aeromonas sp. and should be considered in the epidemiology of A. hydrophila gastroenteritis.

Wounds caused by corn-harvesting machines: an unusual source of infection due to gram-negative bacilli

The infectious complications in 23 patients with mutilating wounds due to trauma during corn harvesting were compared with those in 41 patients with factory-related hand injuries of similar severity. Initial cultures revealed bacterial growth in 89% of the agricultural wounds and in 63% of the factory wounds. A mean of 3.8 initial bacterial species were isolated per corn-harvesting wound vs. 0.9 species per factory wound. Gram-negative rods were recovered from 81% of the agricultural wounds; the commonest of these organisms were Enterobacter species and Xanthomonas maltophilia. Only 7% of factory-wound cultures grew gram-negative rods. Osteomyelitis, all with gram-negative rods, developed in five (22%) of the patients with farm injuries but did not occur in patients with factory wounds. More gram-negative rods were recovered from environmental cultures of corn-harvesting machines and corn plants than from those of factory machinery.

Clinical and microbiological features of Aeromonas hydrophila-associated diarrhea

The prevalence of Aeromonas hydrophila in stool specimens from patients with diarrhea was studied during 18 months. A. hydrophila was found in 1.1% of patients with diarrhea and in none of 533 control patients (P less than 0.02). Cases were detected 1.5 times more often during the summer months than the winter months, and most occurred in children less than 2 years of age. Clinical features included fever greater than 38 degrees C (55%), abdominal cramps (35%), vomiting (25%), and duration of illness greater than 10 days (50%). Detection of A. hydrophila in stools was facilitated by the use of sheep blood agar with 15 micrograms of ampicillin per ml which was flooded with oxidase reagent after growth. A cytotoxin was produced by 62% of the isolates, and the cytotoxic strains showed positive results in a hemolysin assay and a lysine decarboxylase reaction.

Granulomas of the vocal cords caused by Sporothrix schenckii

A 42-year-old female acquired an acute respiratory infection one week after working in a sphagnum moss packing plant. Three and one half months later direct laryngoscopic examination, done because of persistent hoarseness, revealed granulomas of the left true cord. Initial biopsy showed noncaseating granulomas, and a repeat biopsy with fungal cultures grew Sporothrix schenckii. The patient was treated with an oral solution of saturated potassium iodide and gradually improved although mild hoarseness has persisted.

Psoas muscle abscess due to Yersinia enterocolitica

A psoas muscle abscess due to Yersinia enterocolitica developed in a 71-year-old man with mild type II diabetes mellitus. There was no evidence of gastrointestinal infection or septicemia, and treatment with computed tomography-directed percutaneous drainage and cefoxitin resulted in cure. This represents the first known reported case of psoas abscess due to Y. enterocolitica.

Human orf infection complicated by erythema multiforme

A 35-year-old woman developed an orf infection of the fingers after contact with an infected goat. Following the primary orf infection, erythema multiforme developed and was controlled with prednisone. The association between erythema multiforme and orf is discussed; also, it is noted that orf is another viral condition that should be added to the agents that can initiate erythema multiforme.

Nitrofurantoin-induced granulomatous hepatitis

Nitrofurantoin has been described as a cause of both hepatocellular cholestatic hepatic injury. A case report of a patient in whom granulomatous hepatitis developed attributed to nitrofurantoin is given.

Carbenicillin for treatment of Bacteroides fragilis infections: why not penicillin G?

Carbenicillin has been advocated for treatment of infections caused by Bacteroides fragilis and other anaerobic bacteria. Wide-scale use of the drug in this setting could result in a substantial increase in carbenicillin-resistant Pseudomonas aeruginosa, an effect that would have serious implications. Thirty-four strains of B. fragilis, one-half from bacteremic infections, were tested in vitro, and penicillin G was found to be twice as active as carbenicillin on an equal weight basis; 94% of the strains were inhibited by 32 microgram of penicillin/ml, a level easily achieved therapeutically. Penicillin killed B. fragilis organisms as rapidly as carbenicillin. In two subjects given equivalent doses (100 mg/kg intravenously) of carbenicillin and aqueous penicillin G, the bactericidal activity of serum against B. fragilis after administration of each drug was the same. Controlled clinical trials of treatment of anaerobic bacterial infections with penicillin G in high dosage, carbenicillin (or closely related ticarcillin), clindamycin, and chloramphenicol should be undertaken. Carbenicillin (and ticarcillin) for the present would seem better reserved for P. aeruginosa infections.

Mucormycosis. A complication of critical care

Lethal nosocomial mucormycosis developed in three previously well individuals while they were receiving intensive care for acute hemorrhagic pancreatitis, for cardiogenic shock, and for a ruptured intra-abdominal aortic aneurysm. In two cases, the condition was first seen as progressive cavitary pneumonia refractory to antibacterial therapy; Mucoraceae was identified in all three patients only at autopsy. Each patient had received large doses of corticosteroids and broad-spectrum antibiotics, and all had suffered from respiratory failure, acute renal failure with acidosis, and severe hyperglycemia in association with total parenteral nutrition. Mucoraceae should be regarded as an additional nosocomial pathogen in the setting of advanced life-support care.

Ocular sporotrichosis mimicking mucormycosis in a diabetic

Primary sporotrichosis of the eye is very rare; most infections are limited to the conjunctiva or adnexa. We report a case of Sporothrix endophthalmitis associated with necrotizing ethmoid sinusitis developing in a young diabetic man with ketoacidosis. The infection clinically resembled rhino-ophthalmic mycormycosis. Cure followed evisceration and an abbreviated course (215 mg) of amphotericin B. Sporothrix must now be regarded as another fungal agent capable of causing primary rhino-ophthalmic infection similar to Mucor.

Efficacy of direct Gram stain in differentiating staphylococci from streptococci in blood cultures positive for gram-positive cocci

A preponderance of clusters seen on direct Gram stain of blood cultures positive for gram-positive cocci was 98% sensitive and 100% specific for identification of staphylococcal species or of Peptococcus. A preponderance of chains, pairs, or both was 100% sensitive and 98% specific for identifying streptococci. Further presumptive identification of either staphylococci or streptococci based on microscopic morphology was unreliable. The direct Gram stain is highly reliable for differentiating staphylococci from streptococci and should be of considerable value to clinicians selecting initial antimicrobial therapy.