Ampicillin-resistant Haemophilus influenzae. 1. Incidence, mechanism, and detection

Highlights Regarding the Use of Metallic Nanoparticles against Pathogens Considered a Priority by the World Health Organization

The indiscriminate use of antibiotics has facilitated the growing resistance of bacteria, and this has become a serious public health problem worldwide. Several microorganisms are still resistant to multiple antibiotics and are particularly dangerous in the hospital and nursing home environment, and to patients whose care requires devices, such as ventilators and intravenous catheters. A list of twelve pathogenic genera, which especially included bacteria that were not affected by different antibiotics, was released by the World Health Organization (WHO) in 2017, and the research and development of new antibiotics against these genera has been considered a priority. The nanotechnology is a tool that offers an effective platform for altering the physicalchemical properties of different materials, thereby enabling the development of several biomedical applications. Owing to their large surface area and high reactivity, metallic particles on the nanometric scale have remarkable physical, chemical, and biological properties. Nanoparticles with sizes between 1 and 100 nm have several applications, mainly as new antimicrobial agents for the control of microorganisms. In the present review, more than 200 reports of various metallic nanoparticles, especially those containing copper, gold, platinum, silver, titanium, and zinc were analyzed with regard to their anti-bacterial activity. However, of these 200 studies, only 42 reported about trials conducted against the resistant bacteria considered a priority by the WHO. All studies are in the initial stage, and none are in the clinical phase of research.

No development of ciprofloxacin resistance in the Haemophilus species associated with pneumonia over a 10-year study

Background

The widespread overuse of antibiotics promotes the development of antibiotic resistance in bacteria, which can cause severe illness and constitutes a major public health concern. Haemophilus species are a common cause of community- and nosocomial-acquired pneumonia. The antibiotic resistance of these Gram-negative bacteria can be prevented through the reduction of unnecessary antibiotic prescriptions, the correct use of antibiotics, and good hygiene and infection control. This article examines, retrospectively, antibiotic resistance in patients with community- and nosocomial-acquired pneumonia caused by Haemophilus species.

Methods

The demographic, clinical, and laboratory data of all patients with community- and nosocomial-acquired pneumonia caused by Haemophilus species were collected from the hospital charts at the HELIOS Clinic, Witten/Herdecke University, Wuppertal, Germany, within a study period from 2004 to 2014. Antimicrobial susceptibility testing was performed for the different antibiotics that have been consistently used in the treatment of patients with pneumonia caused by Haemophilus species.

Results

During the study period of January 1, 2004, to August 12, 2014, 82 patients were identified with community- and nosocomial-acquired pneumonia affected by Haemophilus species. These patients had a mean age of 63.8 ± 15.5 (60 [73.2 %, 95 % CI 63.6 %–82.8 %] males and 22 [26.8 %, 95 % CI 17.2 %–36.4 %] females). Haemophilus species had a high resistance rate to erythromycin (38.3 %), ampicillin (24.4 %), piperacillin (20.8 %), cefuroxime (8.5 %), ampicillin-sulbactam (7.3 %), piperacillin-sulbactam (4.3 %), piperacillin-tazobactam (2.5 %), cefotaxime (2.5 %), and levofloxacin (1.6 %). In contrast, they were not resistant to ciprofloxacin in patients with pneumonia (P = 0.016).

Conclusion

Haemophilus species were resistant to many of the typically used antibiotics. Resistance toward ciprofloxacin was not detected in patients with pneumonia caused by Haemophilus species.

Pharmacy-enforced outpatient drug treatment protocols: a case study of Medi-Cal restrictions for cefaclor

OBJECTIVE

To evaluate whether a pharmacy-enforced treatment protocol successfully limited the use of a high-cost medication to high-risk patients.

DESIGN

A case study cost-effectiveness analysis was conducted to evaluate a treatment protocol for cefaclor. Episodes of care were defined, healthcare expenditures for all services were aggregated, and demographic data were retrieved from a five percent random sample of California Medicaid (Medi-Cal) recipients. Data were available for episodes occurring before cefaclor was made available under Medi-Cal.

SETTING

Medi-Cal added cefaclor to its formulary, limiting its use to patients over 50 years of age with lower respiratory tract infections (LRTIs). The unit of analysis was an episode of outpatient antibiotic treatment.

PATIENTS

Confirmed LRTI episodes and unconfirmed LRTI cefaclor episodes were analyzed, including multiple episodes of treatment for individual patients. A total of 7855 non-cefaclor LRTI episodes and 2556 cefaclor episodes were analyzed.

MAIN OUTCOME MEASURES

The primary outcome measures were healthcare expenditures three months after the initiation of antibiotic therapy, differentiated by type of service.

RESULTS

Physicians directed cefaclor toward higher-risk patients over age 50 years, even in unconfirmed LRTI episodes. Cefaclor use was estimated to reduce posttreatment costs by $388 per patient (p < 0.001), primarily because of reduced hospital expenditures of $366 (p < 0.001).

CONCLUSIONS

Pharmacy-enforced outpatient drug treatment protocols may be a viable alternative to restrictive formularies and prior authorization. In the case of cefaclor, the Medi-Cal treatment protocol appeared to allow high-risk patients better access to a high-cost medication while reducing total posttreatment costs.

Once-daily intramuscular ceftriaxone in the outpatient treatment of severe community-acquired pneumonia in children

Ceftriaxone, a broad spectrum third-generation cephalosporin with a half-life of six to eight hours, was evaluated prospectively in 147 children with severe community-acquired bacterial pneumonia during the period 11/15/88-5/15/89. Thirty-nine of the children had been unsuccessfully treated with vanous oral antibiotics prior to admission [corrected]. All the patients were initially hospitalized and started on once a day intramuscular ceftriaxone. Mean duration of ceftriaxone therapy was five days. Pathogens were recovered from blood cultures of 17 (11.6%) patients and included S. pneumoniae (13 patients), H. influenzae (three, all resistant to ampicillin) and S. viridans (1) [corrected]. All isolates were sensitive to ceftriaxone. An additional patient had L. pneumophila diagnosed by serology. Cure was achieved in 142 (96.6%) patients; improvement was usually observed within 24-48 hours. After 48 hours, 121 (82.2%) children could be discharged and continued the therapy on ambulatory basis. Based on previous experience we estimated that 383 hospitalization days were saved. No serious side effects were observed. Five patients were considered therapeutic failures; two of them developed empyema and one of them required repeated drainage procedures. A third patient experienced a relapse of pneumonia shortly after completion of therapy. The other two remained febrile for more than seven days; their subsequent improvement was unrelated to the antibiotic therapy, suggesting a viral or mycoplasmal syndrome. Our data suggest that once daily intramuscular ceftriaxone can be successfully used for the outpatient treatment of most community-acquired severe bacterial pneumonias in children. In our opinion it represents the treatment of choice for patients who failed treatment with other antimicrobials and are clinically stable enough not to require hospitalization.

Treatment of childhood bacterial meningitis

One hundred and eighty-seven children with identified bacterial meningitis were treated with intravenous cefotaxime: 15 patients were neonates, 79 infants, and 93 were aged from 1 to 14 years. Causative organisms were: Neisseria meningitidis in 80 cases, Streptococcus pneumoniae in 41, Haemophilus influenzae in 40, enteric gram-negative bacilli in 20 and Staphylococcus spp. in six. Enteric gram-negative bacilli included: Salmonella spp. in 14 cases, Klebsiella pneumoniae in two, and Escherichia coli, Enterobacter sakazakii and Acinobacter calcoaceticus in one each; in one case the organism was not specified. Daily dose of cefotaxime was 150 to 300 mg/kg. Concomitant treatment with an aminoglycoside was used in seven cases. One hundred and seventy-two patients (92.0%) were cured. Fever persisted for a mean of five days and meningeal signs for a mean of four days. Fifteen (8.0%) patients died: most [13] of them were admitted in coma, and two in shock. Death occurred in the first 48 h in ten cases. Sterilization of CSF was achieved in the first 72 h of treatment in 155 (90.1%) of the cured patients. Cefotaxime was well tolerated. CSF penetration of cefotaxime was evaluated in seven patients: concentrations ranged from 0.499 mg/l to 2.829 mg/l. Based on this clinical study, cefotaxime is an effective and safe drug for the treatment of childhood bacterial meningitis.

[Respiratory tract infections caused by Haemophilus influenzae in adults]

Pneumonia counts as one of the most frequent severe Haemophilus influenzae infections to afflict adults. 60% of patients with pneumonia caused by type b H. influenzae are more than 50 years old, 30% to 40% are alcoholics, and 30% to 40% have chronic pulmonary disease or other concurrent illness. In the majority of cases there is multilobular, maculate, diffuse and usually bilateral involvement of the pulmonary tissue. The mortality rate due to type b H. influenzae pneumonia ranges between 30% and 40%. In patients with non-bacteriaemic pneumonia caused by non-encapsulated strains of H. influenzae it is rare for several lobes to be involved, there is little exudation and the mortality rate is low. H. influenzae is a significant pathogen in acute epiglottitis in adults and it also appears to play an important role in acute exacerbations of chronic obstructive lung disease (COLD) and acute sinusitis. beta-lactamase production mediated by R-factors or plasmids of gram-negative bacteria is responsible for ampicillin resistance. In 1978 the overall rate of resistance of H. influenzae to ampicillin in American hospitals amounted to 18%. H. influenzae are found in the nasopharynx of people exposed to others infected with H. influenzae. The risk of secondary infection in children who come into contact with patients infected with type b H. influenzae amounts to approximately 2.1%. Adults in close contact with children suffering from severe H. influenzae infections must be warned of the possible risks of secondary infection.

Penicillin resistance in the subgingival microbiota associated with adult periodontitis

In this investigation, the penicillin-resistant and beta-lactamase-producing subgingival microbiota associated with adult periodontitis was identified, and the impact of a recent exposure to penicillin on the recovery of resistant organisms from this microbiota was assessed. Subjects with adult periodontitis were examined clinically and microbiologically. Twenty-one subjects had a documented history of penicillin therapy within the previous 6 months whereas an additional 21 subjects had no history of antibiotic use within 1 year. Subgingival plaque samples were cultured anaerobically on nonselective and penicillin-containing elective media. MICs and beta-lactamase production were determined for the isolates from the elective medium. The penicillin-resistant microbiota consisted primarily of gram-negative organisms, including Bacteroides, Veillonella, Haemophilus, Eikenella, and Capnocytophaga species. The prevalence (P less than 0.05) and proportions (P less than 0.005) of both penicillin-resistant pigmented Bacteroides and Veillonella species were significantly greater in subjects with recent penicillin exposure. Of the penicillin-resistant genera identified, beta-lactamase production was detected in species of pigmented Bacteroides, Capnocytophaga, and Streptococcus. The prevalence of beta-lactamase-producing Bacteroides species was significantly greater in subjects with recent penicillin exposure (P less than 0.05). Of the antibiotics examined, no single agent was uniformly effective against all of the penicillin-resistant strains, but metronidazole and clindamycin were active against all of the penicillin-resistant pigmented Bacteroides strains.

A comparative study of amoxycillin and pivampicillin in persistent Haemophilus influenzae infection of the lower respiratory tract in children with chronic lung disease

A double-blind cross-over study was undertaken to compare the efficacy of amoxycillin and pivampicillin on Haemophilus influenzae infection of the lower respiratory tract in children. 20 patients with cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD) due to other causes were included in the study. All patients had a history of regularly harbouring H. influenzae in sputum and repeated treatment failures with pivampicillin. 18 completed two 14-day courses in random order with equimolar doses of pivampicillin (80 mg/kg/day) and amoxycillin (62 mg/kg/day). Both drugs were well tolerated with no serious side effects, but pivampicillin was associated with more pronounced nausea. In steady state the mean serum concentrations of antibiotics 2 and 4 h after medication were 9.7 and 3.7 micrograms/ml for pivampicillin and 19.1 and 7.9 micrograms/ml for amoxycillin (p less than 0.01). Eradication of H. influenzae and clinical improvement was seen in one-third of the courses with both drugs. Betalactamase producing ampicillin-resistant strains emerged during 58% of the amoxycillin courses, but only in 16% of the pivampicillin courses (p less than 0.001). The high number of treatment failures and the development of resistant strains indicate that betalactamase inhibitors may possibly improve the efficacy of these drugs, especially of amoxycillin, in these patients.

Clinical and therapeutic aspects of Haemophilus influenzae pericarditis in pediatric patients

Two cases of Haemophilus influenzae type B pericarditis are presented which demonstrate the major clinical features and sequelae of this serious illness. These cases are analyzed together with 77 others from the literature to characterize the clinical features, natural history, and optimal therapy. H. influenzae pericarditis is an increasingly frequent disease of young children. A mild prodromal illness is often followed by rapid progression of cardiac compromise until death ensues, unless pericarditis is diagnosed and treated appropriately. The development of cardiomegaly in a febrile patient with a Haemophilus infection is an indication for echocardiography, which is diagnostic of the pericardial effusion. Initial cultures of pericardial aspirates will be positive in 75% of cases even when antibiotic therapy has been initiated. Use of appropriate parenterally administered antibiotics, in combination with early surgical pericardial drainage or partial pericardiectomy, should minimize morbidity and mortality and prevent acute constrictive sequelae.

Hemophilus influenzae respiratory infection in adults. 2. Treatment guidelines

Once a Hemophilus influenzae isolate is identified as the cause of a respiratory tract infection in an adult, it should be tested for beta-lactamase production, ie, for ampicillin resistance. The incidence of ampicillin-resistant strains of H influenzae is increasing. The Centers for Disease Control in Atlanta estimates an average incidence nationwide of 18% to 22%; the rate varies considerably from community to community. Thus, practitioners should be aware of the ampicillin-resistance rate in their community and should keep this rate in mind especially when treating patients empirically. Patients with H influenzae infections who are acutely ill, who fail to respond to ampicillin, or who are known to have an ampicillin-resistant infection on the basis of laboratory findings should receive therapy designed to combat ampicillin-resistant strains.