Severe intrauterine herpes simplex disease with placentitis in a newborn of a mother with recurrent genital infection at delivery

We present a case of fatal herpes simplex type 2 (HSV-2) in a premature infant born to a mother diagnosed with recurrent HSV-2, based on history and HSV serology results. It was clinically evident at delivery, and subsequently confirmed by laboratory studies that the infant was infected before delivery. There was histopathologic evidence of placentitis and chorioamnionitis upon examination of the placenta and fetal membranes. This case illustrates a relatively uncommon complication of recurrent genital herpes at delivery--intrauterine transmission to the fetus from a primary episode during pregnancy.

Activity of faropenem against resistant isolates of Streptococcus pneumoniae

An in vitro study of the activity of 9 agents against 181 US pediatric isolates of Streptococcus pneumoniae identified imipenem and faropenem as the most active agents. Overall, faropenem was the most potent oral agent inhibiting 98% of isolates at 1 microg/mL.

Activity of oral agents against pediatric isolates of Streptococcus pneumoniae

An in vitro study of the activity of 10 oral agents against 153 pediatric isolates of Streptococcus pneumoniae identified moxifloxacin and levofloxacin as the most active agents regardless of penicillin or macrolide susceptibility. Moxifloxacin inhibited all strains at 0.25 microg/ml and was 8- to 16-fold more potent than levofloxacin.

Varicella vaccine

Varicella vaccine is safe, effective, and cost-effective in healthy children, adolescents, and adults. Breakthrough cases of MVLS are significantly milder than wild-type varicella infection. No severe adverse events have been reported following vaccination, and the incidence of herpes zoster is less in vaccinees than in individuals who have had natural varicella infections. To date, there is no evidence waning immunity following vaccination. "New and improved" varicella vaccines that may be more effective than the current vaccine and can be stored at refrigerator temperatures may soon become available in the United States.

Activity of moxifloxacin against pathogens with decreased susceptibility to ciprofloxacin

A panel of 279 clinical isolates of Gram-positive cocci and Gram-negative bacilli with varying levels of resistance to ciprofloxacin were analysed for susceptibility to moxifloxacin, ciprofloxacin, ofloxacin and nalidixic acid. Moxifloxacin was eight- to 32-fold more potent than ciprofloxacin and ofloxacin against staphylococci and Streptococcus pneumoniae, and equivalent to eight-fold more potent against enterococci. Although ciprofloxacin was intrinsically more potent than the other quinolones against highly susceptible Gram-negative isolates, the percentages of Gram-negative isolates susceptible to 1 mg/L of moxifloxacin or ciprofloxacin, or 2 mg/L of ofloxacin were 78%, 80% and 76%, indicating in-vitro equivalence of the agents against a collection that included isolates with diminished quinolone susceptibility. Staphylococci were analysed according to their ciprofloxacin susceptibility status. As ciprofloxacin resistance increased to high levels, all quinolone MICs increased, but moxifloxacin and ofloxacin MICs increased less than ciprofloxacin MICs. In mutational studies moxifloxacin inhibited more mutants (69%) at a concentration of 1 mg/L than did ciprofloxacin (63%) at 1 mg/L or ofloxacin at 2 mg/L (31%). The study indicated that moxifloxacin is more potent than ciprofloxacin and ofloxacin against Gram-positive pathogens, may be comparable in activity against less quinolone-susceptible Gram-negative isolates (other than Pseudomonas aeruginosa), and is less affected than ciprofloxacin by mechanisms responsible for increasing quinolone resistance in staphylococci.

In-vitro activity of levofloxacin against Streptococcus pneumoniae with various levels of penicillin resistance

This in-vitro study was designed to compare the activity of levofloxacin with that of ciprofloxacin, ofloxacin, erythromycin, penicillin, amoxycillin, loracarbef, cefaclor, cefpodoxime, ceftriaxone, trimethoprim-sulphamethoxazole, clindamycin and vancomycin against a collection of 202 Streptococcus pneumoniae isolates (56% susceptible to penicillin, 34% intermediate, 10% resistant). The isolates (60% nasopharyngeal, 40% middle ear) were obtained from otherwise healthy children at child care centres in urban and rural Nebraska, and at a paediatric clinic in rural Kentucky. MICs were determined by NCCLS agar dilution methodology using an inoculum of 10(4) cfu/spot. Using NCCLS breakpoints, the percentage of penicillin-intermediate and -resistant strains susceptible to the evaluable agents were, respectively, as follows: levofloxacin (99%, 100%), ofloxacin (87%, 100%), erythromycin (52%, 65%), ceftriaxone (93%, 25%), trimethoprim-sulphamethoxazole (7%, 0%), clindamycin (93%, 100%) and vancomycin (100%, 100%). Without NCCLS interpretive criteria, no conclusions could be made concerning the susceptibility of penicillin-intermediate and -resistant strains to the other study drugs. All beta-lactam antibiotics, erythromycin and trimethoprim-sulphamethoxazole were less active against penicillin-resistant strains, indicating that these may be suboptimal agents for empirical therapy for suspected S. pneumoniae infections in these patient populations. However, levofloxacin, ofloxacin, clindamycin and vancomycin were equally active against penicillin-susceptible and -resistant strains. These data suggest that the efficacy of levofloxacin should be examined in both adult and paediatric S. pneumoniae infections involving body sites where levofloxacin concentrations > 2 mg/L can be achieved safely.

Rationale behind high-dose amoxicillin therapy for acute otitis media due to penicillin-nonsusceptible pneumococci: support from in vitro pharmacodynamic studies

To evaluate whether increased doses of amoxicillin should be used to treat acute pneumococcal otitis media, an in vitro pharmacokinetic model was used to evaluate the killing of pneumococci by amoxicillin when middle ear pharmacokinetics were simulated. Logarithmic-phase cultures were exposed to peak concentrations of 3, 6, and 9 microg of amoxicillin per ml every 12 h, and an elimination half-life of 1.6 h was simulated. Changes in viable bacterial counts were measured over 36 h. All three doses rapidly decreased the viable bacterial counts of penicillin-susceptible strains below the 10-CFU/ml limit of detection by 6 to 10 h and maintained counts below this limit through 36 h. The 3-microg/ml peak dose was much less effective against two of three strains with intermediate penicillin resistance and all three penicillin-resistant strains, with bacterial counts approaching those in drug-free control cultures by 12 h. The 6-microg/ml peak dose completely eliminated two of three strains with intermediate penicillin resistance and maintained viable counts of the other nonsusceptible strains at 1.5 to 2 logs below the initial inoculum through 36 h. The 9-microg/ml peak dose was most effective, completely eliminating all three strains with intermediate penicillin resistance and maintaining the viable counts of the resistant strains at 3 to 4 logs below the original inoculum. The pharmacodynamics observed in this study suggest that peak concentrations of amoxicillin of 6 to 9 microg/ml may be sufficient for the elimination of penicillin-nonsusceptible pneumococcal strains causing otitis media, especially those with intermediate resistance to amoxicillin. In vivo pharmacokinetic studies are needed to determine if these levels can be achieved in middle ear fluid with amoxicillin at 70 to 90 mg/kg/day divided into two daily doses. If these levels are reliably achieved, then clinical studies are warranted.

Trovafloxacin, a new fluoroquinolone with potent activity against Streptococcus pneumoniae

An in vitro study of the activity of 15 antibacterial agents against 202 recent pediatric isolates of Streptococcus pneumoniae from urban and rural Nebraska and rural Kentucky identified trovafloxacin, ofloxacin, clindamycin, and vancomycin as the most active agents and equally active against both penicillin-susceptible and--resistant strains. In contrast, six beta-lactams, three macrolides, and trimethoprim-sulfamethoxazole were less active overall, especially against penicillin-intermediate and--resistant strains. Trovafloxacin inhibited all strains at a concentration of < or = 0.25 micrograms/ml and was 8- to 16-fold more potent than ofloxacin or ciprofloxacin.

Influenza vaccination following liver transplantation in children

Our objective was to determine the immunologic response to two influenza vaccine doses in 39 children who had undergone liver transplantation. Patients received two doses of trivalent inactivated influenza vaccine 4 weeks apart. Sera were collected 4 weeks after each dose and analyzed by a hemagglutination inhibition assay (HAI) for evidence of antibody response to the antigens A/Taiwan/1/86 (H1N1), A/Beijing/32/92 (H3N2), and B/Panama/45/95. Patients with HAI titers of 1:40 or greater were considered to have protective titers. Twenty-six (67%) patients showed a 1:40 or greater titer response to A/Beijing/32/92 1 month after the first vaccination. Only two additional patients were found to have similar titers after the second dose. A higher proportion of patients with protective titers were on smaller amounts of prednisone for body weight or alternate day low dose (< 10 mg/day) prednisone compared to patients on daily low dose or daily high dose prednisone. Patients with protective titers were significantly older (9.0 +/- 2.8 years) than those without protective titers (4.2 +/- 3.4 years, p = .002) following the first inoculation of the A/Beijing/32/92 vaccine component. Similar results were found for the second vaccination and with the H1N1 antigen. Cyclosporine level, gender, and body mass index were not associated with any outcome measures. We conclude that most liver transplant recipients had a protective antibody titer after a single influenza inoculation, but little further advantage was gained after an additional dose. Vaccination of household contacts of younger patients and those patients on daily prednisone or patient chemoprophylaxis may offer greater benefit in prevention of influenza in liver transplant recipients than multiple vaccine doses with current vaccine preparations.

Colonization with penicillin-nonsusceptible Streptococcus pneumoniae in urban and rural child-care centers

OBJECTIVES

To determine the prevalence of penicillin-nonsusceptible Streptococcus pneumoniae (NS-SP) at 12 child-care centers (CCC) in urban and rural Nebraska and to evaluate the genetic diversity of pneumococcal strains present in the CCC environment.

METHODS

Nasopharyngeal cultures for S. pneumoniae were obtained from children 2 to 24 months old. Capsular serotyping, pulsed field gel electrophoresis (PFGE) and microbroth dilution MICs were performed for all S. pneumoniae. Antibiotic exposure was also evaluated as a potential risk factor for colonization with NS-SP.

RESULTS

Nasopharyngeal colonization with S. pneumoniae was present in 121 (56%) of 215 children. The MICs of penicillin were 0.12 to 1.0 microgram/ml for 57 (47%) and > 1.0 microgram/ml for 10 (8%) isolates. Clindamycin MICs of > 0.5 microgram/ml were found in 6 isolates (5%). MICs of ceftriaxone were 0.5 microgram/ml in 28% of S. pneumoniae and 1.0 microgram/ml in 7%. PFGE and capsular serotyping demonstrated multiple strains that were penicillin-nonsusceptible in both the urban and rural CCC. PFGE and capsular serotype defined shared strains within each CCC, but some PFGE "types" could be found in multiple serotypes. Antibiotic exposure during the 2 months before nasopharyngeal culture was not a statistically significant risk factor for nasopharyngeal colonization with NS-SP.

CONCLUSIONS

NS-SP are highly prevalent in urban and rural Nebraska. PFGE similarities between serotypes may reflect "serotype switching" but may also reflect genetic similarity between S. pneumoniae strains.

Colonization with penicillin-resistant Streptococcus pneumoniae in a child-care center

We obtained nasopharyngeal cultures for Streptococcus pneumoniae from 54 children ages 2 to 24 months attending an Omaha child-care center (CCC) in April 1994. Thirty-two (59%) of the 54 children were colonized with S. pneumoniae belonging to serotypes 23, 19, 6 and 11. Seventeen (53%) of the pneumococcal isolates were highly resistant to penicillin (minimal inhibitory concentration > or = 2.0 micrograms/ml; HR-SP) and 7 (22%) were intermediately resistant to penicillin (0.12 < or = minimal inhibitory concentration < or = 1.0 microgram/ml; IR-SP). Within each pneumococcal capsular serotype, there were 1 to 3 DNA subtypes based on pulsed field gel electrophoresis analysis. A single pulsed field gel electrophoresis strain predominated in most CCC rooms, suggesting horizontal transmission among cohorted children. Nasopharyngeal cultures obtained 4 months later revealed similar S. pneumoniae colonization rates (28 of 52, 54%); however, only 2 (7%) of 28 isolates were HR-SP and 11 (39%) were IR-SP. Colonization with resistant pneumococci persisted after 4 months in 4 (12%) of 34 children cultured on both occasions. Antibiotic use by attendees had decreased notably between the two sampling periods, suggesting that selective pressure within the CCC might contribute to seasonal variation in colonization rates with HR-SP and IR-SP. We conclude that multiple genetic clones of penicillin-resistant pneumococci can occur simultaneously in a single CCC, especially during periods of heavy antibiotic selection pressure. However, individual clones of penicillin-resistant S. pneumoniae may be spread from child to child, suggesting that colonization with penicillin-resistant S. pneumoniae should now be considered a CCC-associated phenomenon.

Penicillin-resistant Streptococcus pneumoniae in acute otitis media: risk factors, susceptibility patterns and antimicrobial management

From January, 1992, to January, 1994, penicillin-resistant (minimal inhibition concentration (MIC) > 0.06 microgram/ml) Streptococcus pneumoniae (PRSP) isolates accounted for 48 (17%) of 283 isolates from acute otitis media (AOM) or recurrent AOM in 246 ambulatory patients in rural Kentucky. By broth microdilution, relatively penicillin-resistant (MIC > 0.06 to 1.0 microgram/ml) and highly penicillin-resistant (MIC > or = 2.0 micrograms/ml) strains were detected in 25 (16%) and 23 (15%), respectively, of 157 pneumococcal middle ear isolates. Using 1994 National Committee for Clinical Laboratory Standards breakpoints for pneumococci (unavailable for oral cephalosporins except cefuroxime), highly PRSP strains were almost uniformly susceptible to clindamycin and vancomycin. In contrast highly PRSP strains were resistant to most oral antimicrobials customarily used for AOM with one-third of strains highly resistant (MIC > or = 2.0 micrograms/ml) to ceftriaxone. Serotypes 6B, 19F and 23F accounted for 95% of highly PRSP strains and serotype 9V for 48% of relatively PRSP strains. By multivariate analysis, otitis-prone condition (P = 0.0008) and number of antibiotic courses before day of culture (P < 0.0001) were independently predictive of PRSP. Highly PRSP isolates were more commonly isolated from patients recently treated within 3 days (30%) vs. those who completed therapy more than 3 days earlier (2%) (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of values of antibody to Bordetella pertussis antigens in young German and American men

Pertussis is well controlled in the United States by routine childhood immunization. In contrast, this disease is endemic and epidemic in Germany because routine immunization has not been implemented. To gain information relating to the epidemiology of Bordetella pertussis infections, we examined the prevalence and magnitude of B. pertussis agglutinins and of IgG and IgA antibodies (detected by enzyme-linked immunosorbent assay) to four B. pertussis antigens--lymphocytosis-promoting factor, filamentous hemagglutinin, pertactin, and fimbriae-2--in the sera of 119 American university students and 119 German military recruits of similar age. Geometric mean titers of agglutinins and geometric mean values for IgG antibodies to the four antigens were two- to threefold higher in sera from the American students than in sera from German recruits. In contrast, the geometric mean IgA values and the percentage of subjects with detectable IgA antibodies to the four antigens were similar in the two populations. Since IgA antibody results mainly from infection and not from immunization, our data suggest that B. pertussis infections are common among both American and German young adults despite the marked difference in rates of clinical pertussis in the two countries.

Clinical survey of natural varicella compared with breakthrough varicella after immunization with live attenuated Oka/Merck varicella vaccine

OBJECTIVE

To prospectively characterize varicella occurring in children previously immunized with a live attenuated varicella vaccine (breakthrough varicella) through daily observation by medical personnel and to compare it with natural varicella followed in the same manner.

DESIGN

A blinded clinical survey.

SETTING

Four pediatric practices (two private; two hospital-based).

PARTICIPANTS

Healthy 12-month-old through 17-year-old children with chickenpox were studied; 92 had natural varicella and 58 had breakthrough varicella. SELECTION PROCEDURES AND INTERVENTIONS: Study personnel, unaware of vaccination status, documented the clinical characteristics of each patient in the office or at the patient's home each day from enrollment until the day after the total number of lesions increased less than 10%. A standard form documenting number and description of lesions, temperature, duration of illness, and associated clinical complaints was completed each day by the same study personnel. Acute and convalescent sera were obtained on breakthrough cases.

MEASUREMENTS AND RESULTS

Antibody to varicella-zoster virus was measured by the glycoprotein-based enzyme-linked immunosorbent assay. Of those with sera available, 85% were serologically confirmed. Eighty-seven percent of enrollees had a known exposure to chickenpox, with at least two thirds of each group having a greater than 4-hour or a household exposure. The numbers of total and vesicular lesions were significantly higher in the natural varicella group, regardless of exposure status (P = .021 to < .001). The group with breakthrough varicella had a significantly lower incidence of fever (P < .001) and a significantly shorter duration of illness (P < .001). Other associated constitutional complaints and complications were not significantly different between groups.

CONCLUSION

Varicella in vaccine recipients is clinically modified and significantly less severe than natural disease.

Microbiologic and clinical aspects of a trial of once daily cefixime compared with twice daily cefaclor for treatment of acute otitis media in infants and children

In this randomized, investigator-blinded multicenter study, tympanocentesis for acute otitis media with effusion in 137 ears from 108 children, 6 months to 12 years of age, revealed 84 definite pathogens and 32 potential pathogens. Twenty-nine aspirates from 23 subjects were sterile. Of the 116 isolates 42 (36%) were Streptococcus pneumoniae, 24 (21%) were Haemophilus influenzae, 9 (8%) were Moraxella catarrhalis, 9 (8%) were Streptococcus pyogenes and 1 (1%) was Staphylococcus aureus. Twenty-two (19%) definite pathogens produced beta-lactamase. Patients were randomized to cefixime (8 mg/kg/day daily) or cefaclor (40 mg/kg/day divided into two doses). Efficacy was determined by pneumatic otoscopy and tympanometry at the end of therapy visit on Days 11 to 14 and up to 4 weeks of follow-up. At end of therapy subjects with definite pathogens exhibited a satisfactory clinical outcome in 26 of 36 (72%) ears for cefaclor and 40 of 48 (83%) ears for cefixime recipients (P = 0.12). For ears with beta-lactamase-producing isolates there were no (0 to 12) cefixime failures but 4 of 10 cefaclor failures (P = 0.03). Diarrhea/loose stools were more frequent in cefixime (16 of 58) than cefaclor (4 of 50) recipients. One cefixime subject required discontinuation of drug. Overall efficacy for treatment of acute otitis media with effusion was not different; however, cefixime appeared more effective for infections caused by beta-lactamase-producing organisms.

Herpes simplex infection associated with short-term use of a fetal scalp electrode. A case report

A case of localized neonatal herpes simplex virus (HSV) infection involved a prior fetal scalp electrode site. Rupture of the fetal membranes, placement of the fetal scalp electrode and delivery occurred within 30 minutes. The mother had no previous history of genital lesions, and no herpetic lesions were noted at delivery.

Antibodies to varicella-zoster virus glycoproteins I, II, and III in leukemic and healthy children

A dot ELISA was used to analyze the antibody response to varicella-zoster virus glycoproteins I, II, and III in leukemic and healthy children who either developed natural varicella or received the live attenuated varicella vaccine. Both groups of children showed an antibody response to these viral glycoproteins. The antibody response to all three glycoproteins showed excellent persistence over the 3-year period of study. None of the glycoproteins provoked an antibody response that could be shown to correlate with protection from breakthrough varicella after household exposure to chickenpox or from zoster in leukemic vaccinees.

Safety and toxicity profile of aztreonam

Aztreonam is the first monocyclic beta-lactam antibiotic released for clinical use. Extensive toxicity and safety data for aztreonam in animals, healthy volunteers and adult patients have been accumulated previously; recently these studies have been extended to children. Overall the incidence of adverse clinical reactions caused by aztreonam is similar to or lower than that caused by comparison drugs. There is no evidence that aztreonam causes significant ototoxicity or nephrotoxicity; biochemical and hematologic abnormalities are rarely significant. Compared with the broad spectrum cephalosporins, aztreonam causes less disruption of normal gastrointestinal flora and consequently a lower incidence of diarrhea. Aztreonam does not displace bilirubin from albumin and penetrates readily into cerebrospinal fluid. Because of negligible immunologic cross-reactivity with other beta-lactams, aztreonam has been safely administered to patients with IgE-mediated penicillin hypersensitivity. These data suggest that aztreonam should be safe and well-tolerated in infants and children with infections caused by susceptible Gram-negative bacteria.

The efficacy of postsplenectomy sepsis prophylactic measures: the role of penicillin

The well documented increased susceptibility of the asplenic host to overwhelming sepsis by encapsulated organisms has led to three popular prophylactic measures in patients: 1) pneumococcal vaccination; 2) vaccination with oral penicillin prophylaxis; or 3) vaccination with penicillin use at the first sign of infection. An animal model (weanling CD-1 rats) was utilized to evaluate these prophylactic measures. One hundred sixty rats underwent splenectomy and were divided into four treatment groups: I) sham vaccination; II) pneumococcal vaccination; III) vaccination and IM penicillin 24 hours after intraperitoneal inoculation of 10(6) Streptococcus pneumoniae type III; IV) vaccination and IM penicillin starting 3 days before IP inoculation. Six days following the bacterial challenge survival rates by group were: I) 5%; II) 25%; III) 100%; IV) 100% (p less than 0.001 by phi 2 likelihood ratio). Mantel- Cox log rank analysis of survival curves yielded significant differences between all groups except III and IV (p less than 0.001). This study in weanling rats supports the use of penicillin in the asplenic host. Daily prophyactic penicillin or penicillin started at the first sign of infection appears to be equally effective. Randomized studies in humans would determine the best regimen.

The protective effect of pneumococcal vaccination following partial splenectomy

Weanling CD-1 male rats were subjected to 100, 75, and 50% splenectomy. One week following splenectomy, animals received either a sham immunization with 0.1 ml NS or pneumococcal immunization with 0.1 ml of a polyvalent (23) vaccine. Eight weeks following surgery, all animals received an intraperitoneal inoculation with 10(6) Streptococcus pneumoniae Type 3 organisms and were observed for mortality. Significant differences in mortality were seen between sham and immunized animals undergoing 100 or 75% splenectomy, while in the 50% group a difference was noted which did not reach statistical significance (Mantel-Cox log rank test). Patients undergoing greater than 50% splenectomy may be afforded greater protection against overwhelming pneumococcal infections by immunization with pneumococcal vaccine.

Selective and differential medium for recovery of Pseudomonas cepacia from the respiratory tracts of patients with cystic fibrosis

A selective and differential medium, OFPBL (oxidation-fermentation base supplemented with agar, lactose, and two antimicrobial agents), for the isolation of Pseudomonas cepacia from respiratory specimens of patients with cystic fibrosis was developed and tested. Among 725 specimens submitted from seven centers over a 4- to 6-month period, 58 (8%) yielded P. cepacia on OFPBL; only 19 of these were recovered on MacConkey or sheep blood agar (P less than 0.001). No isolate was recovered on MacConkey or sheep blood agar alone. Ranges of recovery rates among centers were 0 to 15% on OFPBL and 0 to 10% on MacConkey or sheep blood agar. Ninety percent of P. cepacia isolates were detected on OFPBL in less than or equal to 3 days. Other nonfermenters and yeasts isolated on OFPBL were distinguished from P. cepacia by failure to acidify the medium. The new medium was clearly superior to MacConkey and sheep blood agars for the isolation of P. cepacia from the respiratory secretions of patients with cystic fibrosis.

Randomized study of two dosage regimens of ciprofloxacin for treating chronic bronchopulmonary infection in patients with cystic fibrosis

Twenty-nine adult patients with cystic fibrosis who had chronic bronchopulmonary infection were randomly assigned to receive 750 or 1,000 mg of oral ciprofloxacin every 12 hours for two weeks. Assessments for efficacy and safety were made on treatment Days 7 and 14 and one week following completion of therapy, and pharmacokinetic data were collected on Days 1, 7, and 14. Fifteen of 28 evaluable patients showed clinical improvement, and none had clinical deterioration. The higher dosage of ciprofloxacin did not enhance the clinical response. Statistically significant, stepwise changes in clinical scores, pulmonary function, and sputum concentrations of Pseudomonas aeruginosa and Staphylococcus aureus were noted, but regression toward initial values occurred by one week after treatment. Although all P. aeruginosa isolates were initially inhibited by 2 mg/liter of ciprofloxacin or less, 45 and 35 percent of isolates were resistant after 14 days of therapy and one week later, respectively. Outpatient oral ciprofloxacin therapy was commonly associated with clinical improvement in adult patients with cystic fibrosis who have chronic bronchopulmonary infection, regardless of the emergence of resistant P. aeruginosa, and adverse reactions were infrequent. Further studies must delineate the long-term consequences of the frequent emergence of bacterial resistance.

Pharmacokinetics of two dosage regimens of ciprofloxacin during a two-week therapeutic trial in patients with cystic fibrosis

Twenty-nine adult patients with cystic fibrosis received 750 or 1,000 mg of ciprofloxacin orally every 12 hours for two weeks. Pharmacokinetic data were collected on Days 1, 7, and 14. Pharmacokinetic analyses revealed minor differences between the dosage regimens, and results were similar on the first, seventh, and last day of therapy. Means for peak serum concentration (3.1 to 5.0 micrograms/ml), elimination half-life (4.8 to 5.3 hours), area under the time-concentration curve, and serum clearance (36.8 to 44.5 liter/hour) were similar to previously reported results for patients without cystic fibrosis. Sputum concentrations approximated serum values.

In vitro inhibition of group B streptococcus-induced polymorphonuclear leukocyte aggregation

Evidence suggests that part of the pathophysiologic response seen in group B streptococcal (GBS) sepsis may be due to polymorphonuclear leukocyte (PMN) activation. Indomethacin (INDO), which inhibits eicosanoid metabolism, attenuates the pathophysiologic response stimulated by GBS, possibly due to inhibition of PMN aggregation. We examined the capability of two eicosanoid metabolism inhibitors, INDO and nordihydroguaiaretic acid (NDGA), to inhibit PMN aggregation induced by heat-inactivated opsonized GBS and GBS-activated plasma. Opsonized GBS-induced PMN aggregation was inhibited by INDO (50-500 microM) and NDGA (1-100 microM). Over similar concentration ranges, INDO and NDGA had no significant effect on PMN aggregation induced by GBS-activated plasma. PMNs in plasma aggregate in response to unopsonized GBS. The stimuli for aggregation are opsonized GBS and GBS-activated plasma. INDO (50-500 microM) was unable to inhibit aggregation under this condition. Over the same concentration range in which INDO inhibited opsonized GBS-induced PMN aggregation, INDO was unable to inhibit opsonized GBS-induced superoxide production in PMNs. NDGA was examined but was found to interfere with the assay. The above evidence suggests PMN aggregation via eicosanoid metabolism may play a role in GBS-induced sepsis, which may be attenuated by agents such as INDO and NDGA.

Characterization of polymorphonuclear leukocyte aggregation in vitro induced by heat-inactivated group B streptococcus

We studied the aggregatory characteristics of human polymorphonuclear leukocytes (PMNs) in response to heat-inactivated group B streptococcus. PMNs suspended in physiologic salt solution do not aggregate to heat-inactivated group B streptococcus (GBS) unless the GBS is previously opsonized in autologous plasma. The aggregating activity of both opsonized GBS and activated plasma are reduced if the plasma is decomplemented before incubation with GBS. Pretreatment of PMNs with pronase inhibited opsonized GBS-induced aggregation, suggesting aggregation via cell membrane receptors for opsonic fragments of C3. Pronase pretreatment had no significant effect on aggregation induced by activated plasma or arachidonic acid. Unlike PMNs in physiologic salt solution, PMNs suspended in plasma aggregate when stimulated by unopsonized GBS. GBS aggregates PMNs via complement cascade activation, opsonization, and interaction with cell membrane receptors to stimulate cellular mechanisms resulting in PMN aggregation.

Enoxacin pharmacokinetics and efficacy in CF-1 mice

Mean peak enoxacin serum concentrations in nonfasted CF-1 mice following a single 50, 100, or 200 mg/kg oral dose were 2.0, 4.0 and 11.4 mg/l, respectively, with proportional increases in area under the serum concentration curves. Oral enoxacin was significantly more effective than tobramycin or dicloxacillin in experimental Pseudomonas aeruginosa and Staphylococcus aureus infections respectively. Enoxacin was as effective as tobramycin against P. cepacia and Escherichia coli infections. Enoxacin may be useful as an oral antimicrobial for the treatment of selected systemic bacterial infections.

The comparison of myocardial dysfunction in three forms of experimental septic shock

A rabbit model of septic shock was used to determine if myocardial dysfunction is a common component of shock due to diverse neonatal pathogens, and prostaglandins modulate septic myocardial dysfunction. The infusion of heat-killed Escherichia coli (group I), Haemophilus influenzae (group II), or Staphylococcus epidermidis (group III) produced significant decreases in the first derivative of left ventricular pressure with respect to time (p less than 0.05). Each organism also produced significant changes in mean arterial pressure, cardiac output, and heart rate, while pulmonary artery pressure was altered in groups I and III. Saline-infused control animals (group IV) exhibited no significant changes in any hemodynamic variable. Blood gas variables were not significantly changed in any group. These cardiovascular changes appeared dependent on arachidonic acid metabolism since indomethacin pretreatment prevented the cardiovascular changes induced by bacterial infusion. These results suggest that septic myocardial dysfunction is a common component of gram-negative and gram-positive septic shock, and that myocardial dysfunction is modulated by prostaglandin products.

Aztreonam therapy for serious gram-negative infections in children

Fifty-nine children were enrolled in an open trial of aztreonam, a monocyclic beta-lactam, therapy for serious gram-negative infections. Thirty-six infections were microbiologically evaluable and received five or more days of therapy. Patients' ages ranged from 3 days to 12 years, and diagnoses included pyelonephritis or cystitis (20), deep soft tissue or joint infection (seven), septicemia (four), pneumonia (three), peritonitis, and epiglottitis. Causative bacteria included Escherichia coli and other Enterobacteriaceae, Pseudomonas aeruginosa, and Haemophilus influenzae. The standard regimen was 30 mg/kg every six or eight hours intravenously. All isolates were aztreonam-susceptible and were eradicated during therapy. Two patients had microbiologic relapses: a patient with Salmonella choleraesuis meningitis who was initially treated for only ten days and a patient with E coli pyelonephritis. Clinical cure was achieved in 31 of 36 children. Pharmacokinetic studies performed in six children demonstrated no difference in serum concentrations or pharmacokinetic variables between day 1 and day 7 of therapy. Although several patients had transient eosinophilia (eight), elevated levels of aminotransferase (seven), or thrombocytosis (ten), no clinically significant adverse effects were noted. In this initial, uncontrolled study, aztreonam was effective and safe in the treatment of a variety of serious gram-negative infections in children.

Prostaglandin synthetase inhibition in group B streptococcal shock: hematologic and hemodynamic effects

A rabbit model of group B Streptococcal (GBS) shock was used to study the effects of prostaglandin synthetase inhibition on the hemodynamic and hematologic response to GBS shock. The infusion of heat-killed GBS in groups I and II produced significant decreases in mean arterial pressure, neutrophil counts, and platelet counts (p less than 0.05), and significant rises in concentrations of thromboxane B2 and 6-Keto-PGF1 alpha, the stable metabolites of thromboxane A2 and prostacyclin (p less than 0.05). Administration of indomethacin (4 mg/kg) after GBS infusion (group II) was associated with a significant rise in mean arterial pressure and a significant decline in thromboxane B2 and 6-Keto-PGF1 alpha concentrations (p less than 0.05) but had no effect on GBS-induced hematologic alterations. Indomethacin administration before GBS infusion (group III) prevented alterations in mean arterial pressure and was associated with a decrease in thromboxane B2 and 6-Keto-PGF1 alpha concentrations. Indomethacin in group III did not prevent neutropenia and thrombocytopenia and may have exacerbated neutropenia. Alteration of experimental GBS shock with prostaglandin synthetase inhibition produces disparate hemodynamic and hematologic response.

Buccal cellulitis reevaluated

We studied 72 children (17 prospectively) with acute buccal cellulitis. The median age was 11 months. Fifty-five percent of patients were bacteremic, and three children without meningeal signs or symptoms had concomitant meningitis. Cellulitis aspirate cultures (eight of 35 positive) and urine bacterial antigen tests (13 of 27 positive) were useful in making an etiologic diagnosis. Infections due to other bacteria were clinically indistinguishable from those due to Haemophilus influenzae type b. The right cheek was affected more often than the left, and only 23 (32%) of 72 patients had otitis media ipsilateral to the involved cheek. The pathogenesis of buccal cellulitis likely involves direct mucous membrane invasion rather than spread from the ipsilateral middle ear.

Cefuroxime versus ampicillin plus chloramphenicol in childhood bacterial meningitis: a multicenter randomized controlled trial

In a multicenter randomized trial, 107 children with bacterial meningitis were initially given either cefuroxime or ampicillin plus chloramphenicol. Patients were alternately assigned to 7- or 10-day courses of the designated antimicrobial regimen. CSF isolates included Haemophilus influenzae type b (89, of which 25% were beta-lactamase positive), Streptococcus pneumoniae, and Neisseria meningitidis. Although mean CSF bactericidal titers against Haemophilus isolates were 1:6 in each treatment group, H. influenzae was cultured from CSF in four of 39 patients receiving cefuroxime, 24 to 48 hours after initiation of therapy, compared with none of 40 patients given ampicillin plus chloramphenicol (P = 0.11). Clinical cure rates were similar (95%); one death occurred in each group. One child given cefuroxime had persistent meningitis after 5 days of therapy, and mastoiditis with secondary bacteremia developed in one on day 10. Three patients had relapse or reinfection. One patient who received cefuroxime for 10 days had a relapse of epiglottitis 17 days later, and of the patients given ampicillin plus chloramphenicol, one had a relapse of meningitis 1 week after 7 days of therapy, and bacteremia developed in one 42 days after completion of 10 days of therapy. No increase in either in-hospital complications or relapses occurred with a 7-day treatment course. Proof of the equivalence of the antibiotic regimens and the efficacy of 7-day courses of treatment, as well as the consequences of delayed CSF sterilization, will require additional investigation.

Myocardial dysfunction in group B streptococcal shock

A rabbit model of group B Streptococcal (GBS) shock was used to determine if myocardial dysfunction contributes to GBS shock and, if so, to ascertain if prostaglandins modulate this dysfunction. The infusion of heat-killed GBS (group I) produced a dramatic decrease in the first derivative of left ventricular pressure with respect to time (LVdP/dt) from baseline values (p less than 0.05). LVdP/dt remained stable in rabbits pretreated with indomethacin (group II) and in saline-infused control rabbits (group III), and was significantly different at 30 min from LVdP/dt in group I (p less than 0.05). Values for group I mean arterial pressure, cardiac output, pulmonary vascular resistance, and heart rate and for pH and pO2 after GBS infusion were all significantly different from baseline values and from postinfusion values for groups II and III (p less than 0.05). Systemic vascular resistance and left ventricular end diastolic pressure did not change significantly in any group at any time interval. These results indicate a primary role for myocardial dysfunction in the pathogenesis of GBS shock, and suggest strongly that prostaglandins modulate GBS-induced myocardial dysfunction.

Moxalactam therapy of Haemophilus influenzae type b meningitis in children

Thirty-four children with Haemophilus influenzae type b meningitis were given prospectively either moxalactam (200 mg/kg/day) or ampicillin (400 mg/kg/day) plus chloramphenicol (75 mg/kg/day). One patient in each group died. The mean duration of fever, clinical response, sequential cerebrospinal fluid findings, and incidence of neurologic sequelae were similar between groups. Moxalactam cerebrospinal fluid bioactivity was significantly greater than that of ampicillin or chloramphenicol throughout therapy. Neutropenia, liver enzyme abnormalities, and diarrhea were not significantly different. In eight of 11 patients given moxalactam (versus one of 14 controls) there was complete elimination of gram-negative aerobic flora in the stools by day 10 (P = 0.002); however, none acquired Clostridium difficile. Moxalactam in effective therapy for H. influenzae type b meningitis.

Cefoperazone pharmacokinetics in acute childhood meningitis

We studied the serum pharmacokinetics and cerebrospinal fluid concentrations of cefoperazone in 15 children with acute meningitis. Mean cefoperazone concentrations of 117 micrograms/ml in the serum and 3.8 micrograms/ml in the cerebrospinal fluid were noted 2 hours after a single 100 mg/kg dose. Following multiple 50 or 100 mg/kg doses, the mean peak serum cefoperazone concentrations were 232 and 498 micrograms/ml, respectively, with an overall mean elimination phase half-life of 2.12 hours. The data best fit a linear, two-compartment model. Cerebrospinal fluid concentrations 1.5 to 2.5 hours after the end of cefoperazone infusions ranged from 1.4 to 19.2 micrograms/ml for all doses and states of illness. This represented 1.2% to 6.4% of simultaneous serum values. The cerebrospinal fluid inhibitory titer was greater than or equal to 1:16 in 17 of 18 specimens tested against a strain of Haemophilus influenzae type b resistant to both chloramphenicol and ampicillin. In the doses given, cefoperazone produces adequate cerebrospinal fluid concentrations and bioactivity to treat the common bacterial forms of acute meningitis in infants and children.

In vitro activity of CI-919 (AT-2266), an oral antipseudomonal compound

We tested CI-919 (AT-2266), a nalidixic acid analog, against 555 gram-positive and gram-negative bacteria, using microbroth or agar dilution methods. The activity of CI-919 was compared with those of cephalosporins, tobramycin, ticarcillin, dicloxacillin, rifampin, chloramphenicol, ampicillin, and trimethoprimsulfamethoxazole. The minimal inhibitory concentrations of CI-919 for 90% of isolates were (in micrograms per milliliter): Pseudomonas spp. (including Pseudomonas aeruginosa), 4.0; Enterobacteriaceae, 0.5; Staphylococcus spp., 2.0; Haemophilus influenzae, 0.12; Campylobacter jejuni, 0.12; and enterococci, 16. The minimal inhibitory concentrations of CI-919 for 90% of 82 tobramycin-resistant, gram-negative strains was 4.0 micrograms/ml. CI-919 was bactericidal for most isolates, showing no cross-resistance with unrelated antimicrobial agents, and was stable for 11 weeks at temperatures ranging from 22 to -70 degrees C. Inoculum size and media pH had little effect on the antibacterial activity of CI-919 for nine strains tested. CI-919 may be useful as an oral antibiotic for the treatment of infections due to diverse bacteria, including P. aeruginosa.

Staphylococcal pneumonia in infants and children

Records were reviewed of 79 infants and children with acute Staphylococcus aureus pneumonia admitted to our hospitals during a 13 1/2-year period from 1965 to 1978. Primary staphylococcal pneumonia was diagnosed in 61 infants (median age, 6 months) and secondary pneumonia (disseminated disease) was present in 18 children (median age, 5.5 years). Fever and signs of pleural effusion and respiratory distress were common in primary disease while fever and a toxic appearance were frequent with disseminated illness. Lobar consolidation was the most common initial roentgenographic abnormality and effusions were detected in 80% of infants with primary pneumonia and 61% of those with secondary disease. In the first 12 to 36 hours after admission 22 (28%) infants showed rapid progression of the roentgenographic abnormalities associated with worsening of the clinical condition. S. aureus was grown in blood cultures from 29% of patients with primary disease and from 89% of those with disseminated disease. The case fatality rate was 25%; factors having a significant adverse influence on the rate were admission before 1972, treatment with ineffective antibiotics, bilateral and/or multilobe pulmonary involvement and a white blood cell count of less than or equal to 10,000 cells/cu mm.