临床分离流感嗜血杆菌和副流感嗜血杆菌的耐药性研究

目的 了解上海部分医院分离的流感和副流感嗜血杆菌对常用抗菌药物的敏感性、对β内酰胺类和喹诺酮类药物的耐药机制以及耐药菌株的克隆传播情况.方法 以琼脂稀释法测定氨苄西林等13种抗菌药物对2006年上海5所医院临床分离的156株嗜血杆菌属细菌的体外抗菌活性,头孢硝噻吩纸片法检测β-内酰胺酶,PCR扩增检测TEM和ROB型β-内酰胺酶基因和喹诺酮类耐药株的喹诺酮耐药决定区,以肠杆菌科基因间重复序列聚合酶链反应(ERIC-PCR)比较细菌的同源性.药物敏感性试验结果采用χ2检验,ERIC-PCR条带模型转换数据进行聚类分析.结果 109株流感嗜血杆菌对氨苄西林敏感率为74.3%,而对氨苄西林舒巴坦、头孢菌素类、氟喹诺酮类等敏感率为100.0%.109株流感嗜血杆菌和47株副流感嗜血杆菌β-内酰胺酶产酶率分别为25.7%和19.1%(χ2=0.776,P=0.378),产酶株均检测到TEM基因.109株流感嗜血杆菌中仅1株对环丙沙星耐药,其gyrA基因存在84位丝氨酸突变为亮氨酸,parC基因存在206位甘氨酸突变为精氨酸.ERIC-PCR结果显示,106株流感嗜血杆菌在85%相似度水平可被分为73型.结论 上海地区流感嗜血杆菌临床菌株对除氨苄西林外的其他常用抗菌药物仍保持很高的敏感率.受试流感嗜血杆菌对氨苄西林耐药的主要机制均为产TEM型β-内酰胺酶.在包括氨苄西林耐药株在内的流感嗜血杆菌中,克隆传播尚不普遍.     

Dynamic process of colonization by Haemophilus influenzae in children--is H. influenzae normal flora in the throat?]

Eighty-seven oropharyngeal isolates of Haemophilus influenzae were obtained by two time cultures six months apart from a total of 288 children who attend a kindergarten. We analyzed the strains by comparing their serotypes, biotypes, beta-lactamase activity and by performing electrophoresis of outer membrane proteins on polyacrylamide gels. Only nineteen strains were not identical, the rest of the 68 strains were classified into 23 types. During 6 months at least 15 types of strains lost from this group and 21 types of new strains were obtained. There were no children who had identical pairs of H. influenzae in their oropharynx during the 6 months. The classification of strains in oropharynx suggested that person-to-person transmission of nontypable H. influenzae can occur. We concluded that oropharyngeal colonization by nontypable H. influenzae is not a normal flora in children.     

Role of immunity in the clearance of bacteremia due to Haemophilus influenzae.

The role of antibodies to capsular and somatic antigens in the clearance of Haemophilus influenzae was investigated by active and passive immunization. The clearance index (k) and the proportion of strain b organisms cleared 30 min after intravenous administration (deltaY30) were greater in eight-week-old actively immunized rats (k = 0.693, deltaY30 = 4.07) than in nonimmune animals (k = 0.075, deltaY30 = 0.95)(P less than 0.025 for all); however, clearance correlated imprecisely with titers of bactericidal or anticapsular antibody. In three-week-old rats, intranasal immunization with strain b or U significantly increased (P less than 0.005) the rate of clearance of strains b and U. Passive immunization with antibodies to somatic or capsular antigens significantly increased the rate of clearance (P less than 0.001) and the proportion of bacteria cleared (P less than 0.05) with all test strains. The increased clearance associated with passive immunization correlated with increased splenic uptake of 32P-labeled H. influenzae (r = 0.83, P less than 0.025). Analysis of the disappearance of viable organisms and bacterial 32P suggested that bacteriolysis of H. influenzae did not occur during clearance of the bacteremia. Either antibody to capsular antigen or antibody to somatic antigen, administered or evoked in rats, accelerates intravenous clearance of H. influenzae by promotion of reticuloendothelial phagocytosis.     

Haemophilus parainfluenzae endocarditis. Two cases and review of the literature in the past decade.

Twenty-five cases of Haemophilus parainfluenzae endocarditis have been reported in the past 10 years, providing a better current perspective of this disease. We have recently diagnosed and treated two patients with H. parainfluenzae endocarditis, and both underwent surgical intervention for complications of their disease. H. parainfluenzae and the other Haemophilus species causing endocarditis often present with a subacute course, often escape early cultural detection and mimic fungal endocarditis in the propensity for large vessel embolization. Multiple emboli and occlusion of major arterial vessels are especially notable features of H. parainfluenzae endocarditis and have occurred in approximately 30 per cent of the cases reported in the past 10 years. In contradistinction to other types of bacterial endocarditis, the most common cause of death in this series has been neurologic complications following embolization.Development of large vegetations appears to be common and may be an intrinsic property of the Haemophilus species, but it is likely that it also reflects the duration of the disease. Delay in recovery of the organism from blood cultures is characteristic of H. parainfluenzae endocarditis and may be due to the strict requirement for V factor exhibited by some strains. Echocardiography has proved useful in suggesting the diagnosis of endocarditis when blood cultures are negative.Optimal antibiotic therapy of H. parainfluenzae endocarditis has not been determined, but the reported clinical experience suggests that combination therapy with ampicillin and an aminoglycoside is the current treatment of choice. Failure to eradicate the organism after a prolonged trial of appropriate antibiotic therapy is not unusual. Indications for surgery in H. parainfluenzae endocarditis may have to be amended to include potential embolization, especially if large vegetations are demonstrated on echocardiography.     

Invasion of the inner ear by Haemophilus influenzae type b in experimental meningitis

Bacterial interstrain variation for cochlear invasion was studied by intraperitoneal inoculation of infant rats with Haemophilus influenzae type b. Eight pairs of CSF isolates from children with or without deafness due to meningitis were injected into half of each litter in separate experiments. At 48 h, quantitative CSF culture results and CSF white blood cell counts were equivalent for the two groups. Organisms within the cochlea were detected in four of eight animals in each group. There was no difference between the deaf and nondeaf isolates in the degree or frequency of inner ear inflammation in formalin-fixed sections. In separate experiments, animals were inoculated with H. influenzae type b and 24 h later treated with ampicillin, or ampicillin plus dexamethasone. At 48 h, although CSF white blood cell counts were significantly reduced in the steroid group, no difference was noted in the degree of cochlear inflammation between the two groups. The ability of H. influenzae type b to invade the inner ear of infant rats does not correlate with the development of sensorineural deafness in children following H. influenzae type b meningitis. Steroid administration does not appear to diminish the inflammatory reaction within the cochlea more than antibiotics alone in this model, but may delay CSF sterilization by ampicillin.     

Increase in invasive disease caused by Haemophilus influenzae b,the Netherlands, 2020 to 2021

The incidence of most respiratory-transmitted diseases decreased during the COVID-19 pandemic as a result of containment measures. In contrast, in the Netherlands we noted an increase in invasive disease caused by Haemophilus influenzae b (Hib) (from < 0.3/100,000 before 2019 to 0.39 and 0.33/100,000 in 2020 and 2021) in vaccinated and unvaccinated age groups. We did not find a change in vaccine effectiveness against Hib invasive disease (effectiveness > 90%). We discuss factors that may have contributed to this rise.     

Haemophilus influenzae protein E binds to the extracellular matrix by concurrently interacting with laminin and vitronectin

Nontypeable Haemophilus influenzae (NTHi) causes otitis media and is commonly found in patients with chronic obstructive pulmonary disease (COPD). Adhesins are important for bacterial attachment and colonization. Protein E (PE) is a recently characterized ubiquitous 16 kDa adhesin with vitronectin-binding capacity that results in increased survival in serum. In addition to PE, NTHi utilizes Haemophilus adhesion protein (Hap) that binds to the basement-membrane glycoprotein laminin. We show that most clinical isolates bind laminin and that both Hap and PE are crucial for the NTHi-dependent interaction with laminin as revealed with different mutants. The laminin-binding region is located at the N-terminus of PE, and PE binds to the heparin-binding C-terminal globular domain of laminin. PE simultaneously attracts vitronectin and laminin at separate binding sites, proving the multifunctional nature of the adhesin. This previously unknown PE-dependent interaction with laminin may contribute to NTHi colonization, particularly in smokers with COPD.     

Relative proportions of H. influenzae and H. parainfluenzae in the throat and nasopharynx of healthy children

To determine normal proportions of pharyngeal H. influenzae and H. parainfluenzae, qualitative and quantitative mapping of the species in the pharynx of 538 healthy children was carried out. The detection rates of H. influenzae rose to a peak at 4, 5 years, with a slow decline thereafter. In contrast to H. influenzae, the detection rates of H. parainfluenzae rose as the child became older in age. The rates of H. influenzae and H. parainfluenzae of the total cultivable flora showed the same tendency as the detection rates. No consistent seasonal fluctuations was found with H. influenzae. The pharyngeal swab was inferior to the nasopharyngeal swab in each age group, for detecting the carriage of H. influenzae and H. parainfluenzae in the upper respiratory tract. The rate of ampicillin-resistant H. influenzae was 17.7% in the nasopharynx.     

Response of infants to Haemophilus influenzae type b polysaccharide and diphtheria-tetanus-pertussis vaccines in combination

In a multicenter study, responses to a combined vaccine containing standard diphtheria-tetanus-pertussis (DTP) and polyribosylribitol phosphate (PRP), the capsular polysaccharide of Haemophilus influenzae type b, were evaluated in 107 infants who received single doses at two, four, and six months of age and compared with those in 61 infants given single doses of DTP alone on the same schedule. Reaction rates were comparable in the two treatment groups. At seven months of age 61% of the subjects given the combined DTP-PRP vaccine and 8% and of those given DTP alone showed an antibody response to PRP, as defined as a twofold increase in titer over the lowest previous level. Among those given the DTP-PRP combined vaccine, 92% of the positive antibody responses occurred after the third dose. There was a variation in antibody response, possibly due to a difference in the vaccine lots administered.     

Nasopharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Alloiococcus otitidis in young children in the era of pneumococcal immunization, Taiwan

We applied a multiplex polymerase chain reaction (PCR) and culture to detect Streptococcus pneumoniae and detected 3 other respiratory pathogens--Haemophilus influenzae, Moraxella catarrhalis, and Alloiococcus otitidis--simultaneously by PCR, in the nasopharynx of 386 children aged under 5 y. S. pneumoniae was the most common pathogen carried by children in all age groups, with the rate ranging from 15.8% in children aged 3-4 y to 28.6% in children aged 2-3 y. H. influenzae and M. catarrhalis showed similar carriage rates across all the age groups. Only 2 young children (0.5%) carried A. otitidis. Higher carriage of S. pneumoniae was found in children who had not received the heptavalent pneumococcal conjugate vaccine (PCV7). Cefotaxime non-susceptibility was high (51.4%) in S. pneumoniae nasopharyngeal isolates. Serotype 6B was the most common in fully immunized carriers and also in those who received catch-up immunization. Due to low PCV7 coverage in Taiwan, the carriage of vaccine and non-vaccine serotypes of S. pneumoniae in children remains common.     

In vivo and in vitro reactions to antigens of Haemophilus influenzae in bronchial obstruction.

The frequency of precipitating antibody to heat-labile (H(1--2) and heat-stable (HCW and HCF) antigens of Haemophilus influenzae was determined in patients with asthma, chronic bronchitis, cystic fibrosis and bronchiectasis and compared with that in a control group. This showed that the immune response of asthmatic patients to heat-stable antigens was different from that to the heat-labile antigens. Exposure to antigens of H. influenzae is common in all the disease groups. Skin test reactions having the time course and macroscopic appearance of Type I (immediate) and Type III (late) were obtained after prick and intracutaneous skin testing with HCW antigen in varying concentrations in a group of patients with asthma, chronic bronchitis or cystic fibrosis and in a control group. It is suggested that IgE and short-term sensitizing IgG antibodies may be responsible for the immediate reactions while activation of the alternative pathway of complement by endotoxin contained in HCW could be responsible for the late reactions. HCW antigens were shown to release histamine from non-sensitized human leucocytes; HCW and HCF antigens were shown to release histamine from non-sensitized human lung. None of the antigens tested had an effect on beta-receptors in tracheal preparations. It is proposed that these reactions may contribute to the pathogenicity of H. influenzae in the lower respiratory tract.     

A case of pulmonary abscess in which Haemophilus parainfluenzae and Streptococcus intermedius were isolated by percutaneous needle aspiration]

Some microbes, including the Bacteroides species, Staphylococcus aureus and Streptococcus milleri groups, can cause pulmonary abscess. Haemophilus parainfluenzae is usually categorized as one of the normal flora which colonizes in the ears and the nasopharynx, and it has been long considered that H. parainfluenzae has little pathogenicity in the lower respiratory tract and lung parenchymal. In this report, we present a case of pulmonary abscess caused by both H. parainfluenzae and Streptococcus intermedius. The patient was a 75-year-old man who had had total esophageo-gastrectomy because of esophageal cancer. He presented with purulent sputum, and chest X-ray film showed a dense consolidation in the right upper lung field. CT-guided transcutaneous fine needle aspiration was performed as a diagnostic procedure. Since both H. parainfluenzae and S. intermedius had been isolated from the lesion, pulmonary abscess caused by these two pathogens was diagnosed. The patient was treated with panipenem/betamipron, and his symptoms and pulmonary infiltrates on the chest X-ray film improved thereafter. So far, very few cases have been reported in which H. parainfluenzae caused lower respiratory tract infection. Although S. intermedius is known as one of the pathogens of pulmonary abscess, it is possible that H. parainfluenzae could also be pathogenic in infectious diseases of the lung.     

Non-capsulated Haemophilus influenzae in the genital flora of pregnant and post-puerperal women.

Non-capsulated Haemophilus influenzae may cause neonatal septicaemia. Genital carriage of this pathogen was studied in 3 mothers of infected neonates and in 2 pregnant women in the first trimester. A carrier state in 2 of the females was terminated by antibiotic therapy after 3 and 7 months, respectively. A previous carrier had no recurrence of H. influenzae in a subsequent pregnancy. A survey of 544 parturient women revealed a carrier rate of 1.8/1,000 (95% confidence limits: 0.1-11). Carriage of non-capsulated H. influenzae is thus rare, and pregnant women may be successfully treated in order to reduce the risk of neonatal infection. There was no evidence of immunodeficiency in women with non-capsulated H. influenzae in the genital tract.     

Estimating Haemophilus influenzae type b vaccine effectiveness in England and Wales by use of the screening method

In October 1992, Haemophilus influenzae type b (Hib) conjugate vaccine was introduced to infants in the United Kingdom with a "catch-up" program for those aged <4 years. Initially, the rate of invasive Hib disease decreased dramatically but has been increasing since 1999. To determine possible reasons for this increase, the effectiveness of Hib conjugate vaccine was estimated by use of the screening method. Between October 1993 and December 2001, a total of 443 cases of Hib infection occurred in children eligible for vaccination; 363 (82%) were fully vaccinated. Vaccine effectiveness was estimated to be 56.7% (95% confidence interval, 42.5-67.4). Effectiveness was lower in children vaccinated during infancy, compared with those who were vaccinated during the catch-up campaign (P=.0033), declined with time since vaccination (P=.0008), and was lower in children born during 2000-2002, compared with other children scheduled for infant vaccination (P=.0041). Use of a catch-up vaccination program enhanced the control of Hib infection in England and Wales. Since 1999, however, low effectiveness in infants, declining effectiveness with age, and the use of lower-efficacy vaccines have contributed to increased rates of Hib infection. The potential role of boosters needs to be considered.     

Treatment of meningitis and other infections due to ampicillin-resistant Haemophilus influenzae type b in children

Cefotaxime and other cephalosporins were retrospectively evaluated for the treatment of meningitis and non-central nervous system (CNS) infections due to ampicillin-resistant Haemophilus influenzae type b (Hib). Between January 1985 and February 1989, 45 cases of meningitis and 27 cases of non-CNS infection due to ampicillin-resistant Hib were documented at Texas Children's Hospital in Houston. Of the 45 children with meningitis, 26 (57.8%) were treated with cefotaxime, 11 (24.4%) with chloramphenicol, and three (6.7%) with cefuroxime; five children (11.1%) were initially given chloramphenicol but later received cefotaxime instead. In addition, 14 chloramphenicol-treated patients from a previous study were included in this analysis. There were no significant differences in terms of neurologic sequelae or other complications (except diarrhea) between the cefotaxime and chloramphenicol groups. The efficacy of cefotaxime was equivalent to that of chloramphenicol for the treatment of ampicillin-resistant Hib meningitis. Cefuroxime was as safe and effective as chloramphenicol or cefotaxime for the treatment of non-CNS infections due to ampicillin-resistant Hib.     

Prevalence of and detection of resistance to ampicillin and other beta-lactam antibiotics in Haemophilus influenzae in Denmark

The susceptibility of Haemophilus influenzae to penicillin V and G, ampicillin and cefuroxime was investigated by MIC, disc and tablet diffusion methods, using chocolate agar as test medium, to determine the prevalence of ampicillin-resistant isolates and the optimal method for their detection. Eighty-six isolates were clinical isolates collected prospectively from July to September 1998 and 22 isolates were clinical isolates with decreased susceptibility to ampicillin previously referred to the reference laboratory. Eighty-seven isolates were ampicillin-susceptible and 16 were ampicillin-resistant. Thirteen produced beta-lactamases. Among the consecutive isolates 12.8% were resistant. With each of the Rosco Neo-sensitabs containing penicillin G, 2.5 microg ampicillin and 33 microg ampicillin, 3 very major errors occurred (resistant isolates misinterpreted as susceptible) and 5-13 major errors (susceptible isolates misinterpreted as resistant). The AB biodisk containing ampicillin (10 microg) was superior to the penicillin V and G discs, i.e. only 1 very major error occurred and major and minor errors were infrequent. The cefuroxime disc identified 4/8 beta-lactamase-negative ampicillin-resistant isolates. Thus, for susceptibility testing with chocolate agar as test medium, the use of an inoculum of 10(5) colony-forming units, 10 microg ampicillin discs and interpretative zone diameters of > or = 28 mm indicating susceptibility and < or = 25 mm indicating resistance was found to produce reliable identification of ampicillin-resistant isolates of H. influenzae.     

Pericarditis caused by beta-lactamase-producing Haemophilus influenzae: report of two cases in adults and review of the literature

Two adult patients with pericarditis caused by beta-lactamase producing Haemophilus influenzae are reported and their management reviewed. Both had pharyngitis, epiglottitis, pneumonia, empyema, or septicemia and were cured with antimicrobics and pericardial drainage (one by catheter and one by surgery). Eleven previously reported cases of pericarditis caused by Haemophilus influenzae are also reviewed. In reviewing this rare cause of bacteria pericarditis, it is important to recognize the antibiotic resistance profile, the incidence of pericardial tamponade, and the use of surgical drainage. Antibiotic selection for this organism is also discussed, as well as the importance of biotyping.     

Haemophilus influenzae b: a review on the determinants of pathogenicity and immune response to the infection

Haemophilus influenzae is still one of the main causes of diverse invasive diseases in children in México. Epidemiologic data indicate that these processes affect primarily the central nervous system and the respiratory tract. Several factors are involved in the expression of infectious disease by this organism, among them the pathogenic determinants of the parasite and those related with resistance in the host. Occurrence of disease is usually the result of the interaction between these determinants. Knowledge of these pathogenic determinants of the parasite and of factors involved in the immune response of the host have allowed an understanding of the infectious process and have directed research in a least three areas: 1) identification of bacterial membrane fractions related with diagnosis of the disease, 2) screening for immunogenic components in the bacterias as vaccine candidates to be used in the prevention of the disease and, 3) the planning of appropriate alternatives for specific antimicrobial therapy.     

Outcome of meningitis caused by Streptococcus pneumoniae and Haemophilus influenzae type b in children in The Gambia

In developing countries, endemic childhood meningitis is a severe disease caused most commonly by Streptococcus pneumoniae or Haemophilus influenzae type b (Hib). Although many studies have shown that fatality rates associated with meningitis caused by these organisms are high in developing countries, little is known about the long-term outcome of survivors. The purpose of this study was to assess the importance of disabilities following pneumococcal and Hib meningitis in The Gambia. 257 children aged 0-12 years hospitalized between 1990 and 1995 with culture-proven S. pneumoniae (n = 134) or Hib (n = 123) meningitis were included retrospectively in the study. 48% of children with pneumococcal meningitis and 27% of children with Hib meningitis died whilst in hospital. Of the 160 survivors, 89 (55%) were followed up between September 1996 and October 1997. Of the children with pneumococcal meningitis that were traced, 58% had clinical sequelae; half of them had major disabilities preventing normal adaptation to social life. 38% of survivors of Hib meningitis had clinical sequelae, a quarter of whom had major disabilities. Major handicaps found were hearing loss, mental retardation, motor abnormalities and seizures. These data show that despite treatment with effective antibiotics, pneumococcal and Hib meningitis kill many Gambian children and leave many survivors with severe sequelae. Hib vaccination is now given routinely in The Gambia; an effective pneumococcal vaccine is needed.