Clinical challenges in addressing resistance to antimicrobial drugs in the twenty-first century.

It has been more than 60 years since Alexander Fleming discovered the drug that came to be known as penicillin. Antibiotics are now one of the most frequently used medications in the United States and are prescribed by medical professionals in almost every specialty. The past decade has seen an alarming increase in the number of pathogens that are resistant to antimicrobial drugs, in the hospital as well as in the community.(1) Among the gram-positive pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus species are the biggest threats. The situation is even more alarming with respect to gram-negative pathogens, especially because there are currently no late clinical trials involving new anti-infective drugs that are active against these pathogens.

Catfish-related injury and infection: report of two cases and review of the literature.

Two cases of serious infection following catfish spine-related injuries are presented, and the literature on this topic is reviewed. The organisms usually involved in such infections are Vibrio species, Aeromonas hydrophila, Enterobacteriaceae, Pseudomonas species, and components of the flora of the human skin. Irrigation, exploration, and culture of these wounds as well as immunization of the patient against tetanus are recommended. Patients with hepatic disease or chronic illness and immunocompromised individuals are at unusually high risk of fulminant infection due to Vibrio and Aeromonas species and should be treated with antibiotics after sustaining a water-associated wound. Patients with normal host defense mechanisms but with late wound care, punctures involving a bone or a joint, progressive inflammation hours after envenomation, fever, or signs of sepsis are at high risk for secondary infection and should receive definitive wound care and antibiotics. For moderate to severe infections, one of the following combinations constitutes a reasonable empirical regimen: (1) a tetracycline and a broad-spectrum, beta-lactamase-stable beta-lactam antibiotic, or (2) a tetracycline, a beta-lactamase-stable penicillin, and an aminoglycoside.

Tricuspid valve group B streptococcal endocarditis following elective abortion.

Streptococcus agalactiae, a group B streptococcus, has been a well-known cause of postpartum and postabortion endocarditis since the preantibiotic era. Streptococcus agalactiae is capable of infecting normal valves and usually produces left-sided disease. We describe a 30-year-old woman who developed tricuspid valve endocarditis due to S. agalactiae. Excision of the valve and a 4-week course of therapy with vancomycin resulted in cure.

Nosocomial bacterial pneumonias.

Pneumonia is the third most common nosocomial infection and the most difficult to prevent. Fifteen percent of all deaths occurring in hospitals are caused by nosocomial pneumonias. Nosocomial pneumonias prolong hospital stays over 4 days, resulting in at least $3,000 to $5,000 in extra charges per infection. Most cases of nosocomial pneumonias are caused by bacteria, especially gram-negative bacilli. The majority of nosocomial pneumonias appear to result from aspiration of bacteria that have colonized the oropharynx. Additional risk factors include colonization of the oropharynx with gram-negative bacilli, thoracic and upper abdominal surgery, continuous mechanical ventilation, extremes of age, and severity of underlying diseases. Prevention revolves around an effective infection control program, preventing colonization and aspiration, and improving host defense mechanisms. Further research is needed to clarify the role of topical antibiotics and to develop strategies to alter host defenses to prevent or eliminate colonization of gram-negative bacilli.

Progressive disseminated histoplasmosis in patients with the acquired immune deficiency syndrome: a report of 12 cases and a literature review.

Progressive disseminated histoplasmosis is an increasingly common cause of infection in patients with acquired immune deficiency syndrome (AIDS) from areas endemic for histoplasmosis. We report 12 cases of progressive disseminated histoplasmosis associated with AIDS and review 20 previously reported cases. The clinical presentation of progressive disseminated histoplasmosis is nonspecific with persistent fever, weight loss, and splenomegaly. Frequently progressive disseminated histoplasmosis was the initial clue to the presence of AIDS. Bone marrow culture is the best method for establishing a diagnosis. Relapses were common both with ketoconazole and after a 2.0 to 2.5 g course of amphotericin B. This suggests a 2.0 to 2.5 g course of amphotericin B followed by long term ketoconazole suppression may be the best therapeutic regimen in these patients.

Intra-abdominal infections in the elderly: diagnosis and management.

With appendicitis, elderly patients commonly delay 2 or 3 days after symptoms begin before seeking medical attention, the patient often attributing the abdominal discomfort to indigestion, "gas," or constipation. Reduced gastric acidity secondary to gastric surgery, aging, or medications can increase susceptibility to many enteric pathogens, leading to a higher risk of infectious diarrhea.

Cost-effective application of the Centers for Disease Control Guideline for Infection Control in Hospital Personnel.

I have tried to summarize the spirit of the Centers for Disease Control Guideline for Infection Control in Hospital Personnel. By eliminating certain unnecessary practices and preventing one infectious disease, we could have saved the hospital in these examples more than $18,000 in just 1 year. We must continue to evaluate and eliminate unnecessary practices while maintaining a safe environment for our employees.

Use of trimethoprim-sulfamethoxazole for treatment of infections due to Nocardia.

Trimethoprim-sulfamethoxazole (TMP-SMZ) was used for treatment of 34 patients with pulmonary or cutaneous nocardiosis. Of nine patients with primary cutaneous disease, eight had rapid resolution of their infection after short-term therapy and none have relapsed after a follow-up of more than six months. The 25 patients with pulmonary nocardiosis had a good clinical response, but three of five (60%) who completed less than three months of therapy relapsed within four weeks. Of the 10 patients who completed four to six months of therapy, only one (10%) relapsed and this relapse was due to drug resistance. By the method of serial dilution in agar, 96% of 59 isolates of Nocardia had MICs of SMZ of less than 25 micrograms/ml. Fewer than 20% were susceptible to 2.5 micrograms of TMP/ml. Synergy between TMP and SMZ was usually present with ratios of TMP to SMZ of 1:5, 1:1, or 5:1, but was less common at a ratio of 1:20. Disk susceptibility testing was easy to perform and readily separated sensitive from resistant strains. TMP-SMZ is highly effective for the treatment of nocardiosis, but the question of whether it is more effective clinically than a sulfonamide alone remains unanswered.

Haemophilus influenzae infections in adults: characterization of strains by serotypes, biotypes, and beta-lactamase production.

One hundred three cases of bacteremia or meningitis due to Haemophilus influenzae in adults were evaluated. Among 96 episodes of bacteremia, 60% were due to pneumonia and 15% to genital-related infections; 10% had no apparent source of infection. Of 42 isolates serotyped in routine fashion by slide agglutination, 79% were reported as type b. In contrast, of 45 isolates from the same interval with confirmed serotyping (usually by counterimmunoelectrophoresis), only 29% were type b and 64% were nontypable; 26% had been misidentified by routine slide agglutination. The majority (85%) of confirmed typable strains were biotype I. Four (40%) of 10 nontypable obstetrical isolates belonged to the relatively rare biotype IV. Only 2% of isolates were ampicillin-resistant, despite a high resistance rate among pediatric isolates in the same communities. When serotyping is carefully performed, nontypable organisms appear to be the major cause of invasive H. influenzae disease in adults.

Hypoglycemia as a manifestation of sepsis.

Hypoglycemia has rarely been described as a clinical sign of severe bacterial sepsis. We recently encountered nine patients in whom hypoglycemia (mean serum glucose of 22 mg/dl) was associated with overwhelming sepsis. Clinical disease in these patients included pneumonia and cellulitis; in three patients, no focus of infection was apparent. Altered mental status, metabolic acidosis, leukopenia, abnormal clotting studies and bacteremia were common features in these cases. In four patients, no cause for hypoglycemia other than sepsis was present. In five patients, another possible metabolic cause for hypoglycemia was present (alcoholism in four and chronic renal insufficiency in one) although none had been observed to be hypoglycemic on previous hospitalizations. Streptococcus pneumoniae (three cases) and Hemophilus influenzae, type b, (two cases) were the most common pathogens, and the over-all mortality was 67 per cent. The mechanism(s) for hypoglycemia with sepsis is not well defined. Depleted glycogen stores, impaired gluconeogenesis and increased peripheral glucose utilization may all be contributing factors. Incubation of bacteria in fresh blood at room temperature does not increase the normal rate of breakdown of glucose suggesting that the hypoglycemia occurs in vivo. Hypoglycemia is an important sign of overwhelming sepsis that may be more common than has previously been recognized.