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Baciu AP, Baciu C, Baciu G, Gurau G. The burden of antibiotic resistance of the main microorganisms causing infections in humans - review of the literature. J Med Life 2024; 17:246-260. [PMID: 39044924 PMCID: PMC11262613 DOI: 10.25122/jml-2023-0404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 02/21/2024] [Indexed: 07/25/2024] Open
Abstract
One of the biggest threats to human well-being and public health is antibiotic resistance. If allowed to spread unchecked, it might become a major health risk and trigger another pandemic. This proves the need to develop antibiotic resistance-related global health solutions that take into consideration microdata from various global locations. Establishing positive social norms, guiding individual and group behavioral habits that support global human health, and ultimately raising public awareness of the need for such action could all have a positive impact. Antibiotic resistance is not just a growing clinical concern but also complicates therapy, making adherence to current guidelines for managing antibiotic resistance extremely difficult. Numerous genetic components have been connected to the development of resistance; some of these components have intricate paths of transfer between microorganisms. Beyond this, the subject of antibiotic resistance is becoming increasingly significant in medical microbiology as new mechanisms underpinning its development are identified. In addition to genetic factors, behaviors such as misdiagnosis, exposure to broad-spectrum antibiotics, and delayed diagnosis contribute to the development of resistance. However, advancements in bioinformatics and DNA sequencing technology have completely transformed the diagnostic sector, enabling real-time identification of the components and causes of antibiotic resistance. This information is crucial for developing effective control and prevention strategies to counter the threat.
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Key Words
- AOM, acute otitis media
- CDC, Centers for Disease Control and Prevention
- CRE, carbapenem-resistant Enterobacterales
- ESBL, extended-spectrum beta-lactamase
- Hib, Haemophilus influenzae type b
- LVRE, linezolid/vancomycin -resistant enterococci
- MBC, minimum bactericidal concentration
- MBL, metallo-beta-lactamases
- MDR, multidrug-resistant
- MIC, minimum inhibitor concentration
- MRSA, methicillin-resistant Staphylococcus aureus
- PBP, penicillin-binding protein
- SCCmec staphylococcal chromosomal cassette mec
- VRE, vancomycin-resistant enterococci
- XDR, extensively drug-resistant
- antibiotic resistance
- antibiotics
- beta-lactamase
- cIAI, complicated intra-abdominal infection
- cUTI, complicated urinary tract infection
- carbapenems
- methicillin-resistant Staphylococcus aureus
- vancomycin
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Affiliation(s)
| | - Carmen Baciu
- MedLife Hyperclinic Nicolae Balcescu, Galati, Romania
| | - Ginel Baciu
- Sf. Ioan Emergency Clinical Hospital for Children, Galati, Romania
- Faculty of Medicine and Pharmacy, Dunarea de Jos University, Galati, Romania
| | - Gabriela Gurau
- Sf. Ioan Emergency Clinical Hospital for Children, Galati, Romania
- Faculty of Medicine and Pharmacy, Dunarea de Jos University, Galati, Romania
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Thakur AA, Abdalla EM, Saeed L, Abouazab Y, Khalil SK. Non-typeable Haemophilus influenza ventriculitis, a case report and literature review. Ann Med Surg (Lond) 2022; 84:104883. [PMID: 36582859 PMCID: PMC9793223 DOI: 10.1016/j.amsu.2022.104883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/12/2022] [Accepted: 11/07/2022] [Indexed: 11/15/2022] Open
Abstract
Introduction and importance: Haemophilus influenza severe presentations have decreased dramatically after the Hib vaccination was introduced. However, due to the emergence of Multi-drug resistance organisms, severe presentations like meningitis and ventriculitis may occur. Case presentation Here, we have described a rarely reported case of non-typeable Haemophilus influenza ventriculitis in a previously healthy patient. MRI of the head with contrast was suggestive of tiny foci of diffusion restriction in occipital horns of bilateral ventricles with minimal intraventricular pus formation. The diagnosis was confirmed based on blood culture results and MRI findings as the patient refused to have a lumbar puncture procedure for CSF analysis. The patient was treated with intravenous antibiotics and showed a good response. Clinical discussion In the post-HiB immunization era, we have seen a decline in invasive diseases caused by Type B Haemophilus influenza. However, non-typeable Haemophilus influenzae is now on the rise. Central nervous system infection due to non-typable Haemophilus influenza is infrequent as this organism is predominantly a respiratory mucosal pathogen resulting in acute and chronic respiratory tract infections. Multi-drug resistance of non-typeable Haemophilus influenzae is also becoming a cause of concern. Conclusion Ventriculitis secondary to non-typeable beta-lactamase non-producing, ampicillin-resistant (BLNAR) Haemophilus influenza is rare, and more such cases need to be reported within the adult population to avoid under-recognition.
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Affiliation(s)
| | - El Mustafa Abdalla
- Corresponding author. Department of Internal Medicine, Hamad Medical Corporation, Al-Rayyan Road PO Box 3050, Doha, 00000, Qatar.
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Abstract
BACKGROUND Universal vaccination with Haemophilus influenzae type b conjugate vaccines has significantly changed the epidemiology of invasive H. influenzae disease in the United States. We reviewed the epidemiology, clinical features, and outcomes in 61 patients with invasive H. influenzae disease evaluated at Texas Children's Hospital (TCH). METHODS Cases of invasive H. influenzae disease, defined as isolation of the organism from cerebrospinal fluid, blood, synovial fluid or pleural fluid, during 2011 to 2018 among children cared for at TCH in Houston, TX, were included. RESULTS We identified 61 cases of invasive H. influenzae disease in children ≤18 years of age. The overall hospitalization rate due to invasive H. influenzae disease increased between 2011 and 2018 (0 vs. 0.64/1000 hospitalizations; P = 0.019). The majority (80%) of infections occurred in children <5 years of age. Of the 61 H. influenzae infections, 24 (39.3%) infections were caused by nontypeable H. influenzae strains, 18 (29.5%) infections were caused by H. influenzae type a, 12 (19.7%) infections were caused by H. influenzae type f, 3 (4.9%) infections were caused by H. influenzae type e and 4 (6.6%) isolates were not typed. A total of 78.7% of the isolates were β-lactamase negative. The most common clinical presentations were bacteremia without a source, pneumonia and meningitis. CONCLUSIONS The hospitalization rate for H. influenzae invasive disease increased over an 8-year period at TCH. The overall trend was mainly driven by an increasing number of invasive infections caused by nontypeable H. influenzae and H. influenzae type a. Morbidity was substantial, especially in meningitis cases.
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Butler DF, Myers AL. Changing Epidemiology of Haemophilus influenzae in Children. Infect Dis Clin North Am 2017; 32:119-128. [PMID: 29233576 DOI: 10.1016/j.idc.2017.10.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Haemophilus influenzae remains a common cause of illness in children throughout the world. Before the introduction of vaccination, H influenzae type b (Hib) disease was the leading cause of bacterial meningitis in young children and a frequent cause of pneumonia, epiglottitis, and septic arthritis. Clinicians should remain diligent in counseling parents on the dangers of Hib and provide vaccination starting at 2 months of age. The epidemiology of invasive H influenzae disease is shifting. It is imperative that clinicians recognize the changing epidemiology and antibiotic resistance patterns for H influenzae to optimize care in hospital and ambulatory settings.
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Affiliation(s)
- David F Butler
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Seattle Children's Hospital, University of Washington School of Medicine, FA.2.112, 4800 Sand Point Way NE, Seattle, WA 98105, USA
| | - Angela L Myers
- Division of Pediatric Infectious Diseases, Children's Mercy, Kansas City, University of Missouri-Kansas City School of Medicine, 2401 Gillham Road, Kansas City, MO 64108, USA.
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Antony S, Kaushik A, Mauriello C, Chatterjee A. Non-Type b Haemophilus influenzae Invasive Infections in North Dakota and South Dakota, 2013-2015. J Pediatric Infect Dis Soc 2017; 6:281-284. [PMID: 27656134 DOI: 10.1093/jpids/piw053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 08/02/2016] [Indexed: 11/14/2022]
Abstract
Reports of children with non-type b Haemophilus influenzae infection in the United States in recent years have been limited. Here, we report the spectrum and severity of disease associated with invasive non-type b H influenzae infection in 17 patients at 2 tertiary-care children's hospitals over a 2-year period. Meningitis was the most common diagnosis. The majority of the patients had neurologic sequelae, and 1 patient died. The high proportions of hospitalization, intensive care utilization, and neurologic complications reveal that non-type b H influenzae infection was associated with significant morbidity in this pediatric population.
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Affiliation(s)
| | - Ashlesha Kaushik
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Sanford Children's Specialty Clinic and Hospital, University of South Dakota Sanford School of Medicine, Sioux Falls
| | - Clifford Mauriello
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of North Dakota, Sanford Children's Hospital, Fargo
| | - Archana Chatterjee
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Sanford Children's Specialty Clinic and Hospital, University of South Dakota Sanford School of Medicine, Sioux Falls
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Wang XJ, Saha A, Zhang XH. Cost-effectiveness analysis of a universal mass vaccination program with a PHiD-CV 2+1 schedule in Malaysia. COST EFFECTIVENESS AND RESOURCE ALLOCATION 2017; 15:17. [PMID: 28852326 PMCID: PMC5568314 DOI: 10.1186/s12962-017-0079-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 08/12/2017] [Indexed: 11/10/2022] Open
Abstract
Background Currently, two pediatric pneumococcal conjugate vaccines are available in the private market of Malaysia—13-valent pneumococcal conjugate vaccine (PCV13) and pneumococcal polysaccharide and non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV). This study aimed to evaluate the cost-effectiveness of a universal mass vaccination program with a PHiD-CV 2+1 schedule versus no vaccination or with a PCV13 2+1 schedule in Malaysia. Methods A published Markov cohort model was adapted to evaluate the epidemiological and economic consequences of programs with no vaccination, a PHiD-CV 2+1 schedule or a PCV13 2+1 schedule over a 10-year time horizon. Disease cases, deaths, direct medical costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) were estimated. Locally published epidemiology and cost data were used whenever possible. Vaccine effectiveness and disutility data were based on the best available published data. All data inputs and assumptions were validated by local clinical and health economics experts. Analyses were conducted from the perspective of the Malaysian government for a birth cohort of 508,774. Costs and QALYs were discounted at 3% per annum. One-way and probabilistic sensitivity analyses were performed. Results Compared with no vaccination, a PHiD-CV 2+1 program was projected to prevent 1109 invasive pneumococcal disease (IPD), 24,679 pneumonia and 72,940 acute otitis media (AOM) cases and 103 IPD/pneumonia deaths over 10 years, with additional costs and QALYs of United States dollars (USD) 30.9 million and 1084 QALYs, respectively, at an ICER of USD 28,497/QALY. Compared with a PCV13 2+1 program, PHiD-CV 2+1 was projected to result in similar reductions in IPD cases (40 cases more) but significantly fewer AOM cases (30,001 cases less), with cost savings and additional QALYs gained of USD 5.2 million and 116 QALYs, respectively, demonstrating dominance over PCV13. Results were robust to variations in one-way and probabilistic sensitivity analyses. Conclusions A PHiD-CV 2+1 universal mass vaccination program could substantially reduce pneumococcal disease burden versus no vaccination, and was expected to be cost-effective in Malaysia. A PHiD-CV 2+1 program was also expected to be a dominant choice over a PCV13 2+1 program in Malaysia. Electronic supplementary material The online version of this article (doi:10.1186/s12962-017-0079-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiao Jun Wang
- Department of Pharmacy, National University of Singapore, Block S4A, Level 3, 18 Science Drive 4, Singapore, 117543 Singapore.,GSK, 150 Beach Road, #22-00 Gateway West, Singapore, 189720 Singapore
| | - Ashwini Saha
- GSK Pharmaceutical Sdn Bhd, Level 6, Quill 9, 112 Jalan Semangat, 46300 Petaling Jaya, Selangor Malaysia
| | - Xu-Hao Zhang
- Department of Pharmacy, National University of Singapore, Block S4A, Level 3, 18 Science Drive 4, Singapore, 117543 Singapore.,GSK, 150 Beach Road, #22-00 Gateway West, Singapore, 189720 Singapore
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Characterisation of invasive clinical Haemophilus influenzae isolates in Queensland, Australia using whole-genome sequencing. Epidemiol Infect 2017; 145:1727-1736. [PMID: 28260537 DOI: 10.1017/s0950268817000450] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Haemophilus influenzae is an important aetiological organism of both adult and child respiratory disease. The number of non-typeable (NTHi) invasive H. influenzae isolates referred to the Queensland (QLD) Public Health Microbiology laboratory has increased notably year-by-year. In this study we used whole-genome sequencing to molecularly characterise 100 referred invasive H. influenzae, including 74 NTHi isolates over a 15-year period, observing the carriage of capsular and putative virulence genes, including the major adhesins, antimicrobial resistance genes and population diversity. Encapsulated isolates were largely clonal, however NTHi isolates displayed high genetic variability by MLST and single nucleotide polymorphism typing with no dominant clone observed. The only mechanism for β-lactam resistance identified in the QLD isolates was β-lactamase production. No single set of virulence determinants was conclusively associated with invasive QLD NTHi isolates.
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Ho YC, Lee PL, Wang YC, Chen SC, Chen KT. The economic burden of childhood invasive pneumococcal diseases and pneumonia in Taiwan: Implications for a pneumococcal vaccination program. Hum Vaccin Immunother 2016; 11:1081-7. [PMID: 25874476 PMCID: PMC4514427 DOI: 10.1080/21645515.2015.1023969] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Invasive pneumococcal disease (IPD) and pneumonia are the major causes of morbidity and deaths in children in the world. The management of IPD and pneumonia is an important economic burden on healthcare systems and families. The aim of this study was to assess the economic burden of IPD and pneumonia among younger children in Taiwan. We used a cost-illness approach to identify the cost categories for analysis in this study according to various perspectives. We obtained data of admission, outpatient, and emergency department visit data from the National Health Insurance Research (NHIR) database for children <5 y of age between January 2008 and December 2008. A prospective survey was administered to the families of patients to obtain detailed personal costs. All costs are presented in US dollars and were estimated by extrapolating 2008 cost data to 2013 price levels. We estimated the number of pneumococcal disease cases that were averted if the PCV-13 vaccine had been available in 2008. The total annual social and hospital costs for IPD were US $4.3 million and US $926,000, respectively. The total annual social and hospital costs for pneumonia were US $150 million and US $17 million, respectively. On average, families spent US $653 or US $218 when their child was diagnosed with IPD or pneumonia, respectively. This cost is approximately 27%–81% of the monthly salary of an unskilled worker. In conclusion, a safe and effective pediatric pneumococcal vaccine is needed to reduce the economic burden caused by pneumococcal infection.
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Affiliation(s)
- Yi-Chien Ho
- a Department of Cosmetic Applications and Management/Holistic Education Center; Cardinal Tien Junior College of Healthcare and Management ; Taipei , Taiwan
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Moon SK, Lim DJ. Intratympanic Gene Delivery of Antimicrobial Molecules in Otitis Media. Curr Allergy Asthma Rep 2015; 15:14. [PMID: 26130474 DOI: 10.1007/s11882-015-0517-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Otitis media (OM) in children is clinically important because of its detrimental effects on the development of language and motor coordination and is the most common reason for prescription of antibiotics. A recent bacteriological change in OM pathogens such as emergence of antibiotic resistance and vaccination-mediated pathogenic shift urges us to develop a new non-antibiotic strategy. The middle ear epithelium abundantly secretes a variety of antimicrobial molecules suppressing the viability of the common OM pathogens. Recently, we have demonstrated that the adenoviral vector is able to deliver the β-defensin 2 gene to the middle ear epithelial cells in vitro and in vivo, and adenovirus-mediated overexpression of β-defensin 2 is protective for experimental OM. There are many hurdles limiting successful clinical application of gene delivery to the respiratory epithelium of the tubotympanum; however, intratympanic gene therapy with β-defensin 2 is a promising alternative or adjuvant strategy for the management of OM.
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Affiliation(s)
- Sung K Moon
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, 2100 W. 3rd Street, Los Angeles, CA, 90057, USA,
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10
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Abstract
Due to the introduction of the conjugate vaccine against serotype b, neonatal sepsis caused by Haemophilus influenzae became very rare. There is little data in Belgium concerning the prevalence of H. influenzae early onset neonatal sepsis and articles about neonatal sepsis and H. influenzae published in the last decade are scarce. We report two invasive infections with a non-typeable H. influenzae. These cases show that neonatal sepsis caused by non-typeable H. influenzae may be underestimated and we believe that there is need for a better registration of this kind of infection.
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Van Eldere J, Slack MPE, Ladhani S, Cripps AW. Non-typeable Haemophilus influenzae, an under-recognised pathogen. THE LANCET. INFECTIOUS DISEASES 2014; 14:1281-92. [PMID: 25012226 DOI: 10.1016/s1473-3099(14)70734-0] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Non-typeable Haemophilus influenzae (NTHi) is a major cause of mucosal infections such as otitis media, sinusitis, conjunctivitis, and exacerbations of chronic obstructive pulmonary disease. In some regions, a strong causal relation links this pathogen with infections of the lower respiratory tract. In the past 20 years, a steady but constant increase has occurred in invasive NTHi worldwide, with perinatal infants, young children, and elderly people most at risk. Individuals with underlying comorbidities are most susceptible and infection is associated with high mortality. β-lactamase production is the predominant mechanism of resistance. However, the emergence and spread of β-lactamase-negative ampicillin-resistant strains in many regions of the world is of substantial concern, potentially necessitating changes to antibiotic treatment guidelines for community-acquired infections of the upper and lower respiratory tract and potentially increasing morbidity associated with invasive NTHi infections. Standardised surveillance protocols and typing methodologies to monitor this emerging pathogen should be implemented. International scientific organisations need to raise the profile of NTHi and to document the pathobiology of this microbe.
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Affiliation(s)
- Johan Van Eldere
- Department of Microbiology and Immunology, Catholic University Leuven, Belgium; Clinical Department of Laboratory Medicine, University Hospital Leuven, Belgium.
| | - Mary P E Slack
- WHO Collaborating Centre for Haemophilus influenzae, Respiratory and Vaccine Preventable Bacteria Reference Unit, Microbiology Services, Public Health England, Colindale, London, UK
| | - Shamez Ladhani
- Immunisation, Hepatitis and Blood Safety Department, Health Protection Services, Public Health England, Colindale, London, UK
| | - Allan W Cripps
- School of Medicine, Griffith Health Institute, Griffith University, Gold Coast, QLD, Australia
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Abstract
Haemophilus influenzae is a rare cause of soft tissue infection. In this report, we present a case of multifocal necrotizing fasciitis in a healthy adult patient, secondary to Haemophilus influenzae serotype f infection, and we review literature on this rare cause of necrotizing fasciitis.
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Outer membrane protein P5 is required for resistance of nontypeable Haemophilus influenzae to both the classical and alternative complement pathways. Infect Immun 2013; 82:640-9. [PMID: 24478079 DOI: 10.1128/iai.01224-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The complement system is an important first line of defense against the human pathogen Haemophilus influenzae. To survive and propagate in vivo, H. influenzae has evolved mechanisms for subverting this host defense, most of which have been shown to involve outer surface structures, including lipooligosaccharide glycans and outer surface proteins. Bacterial defense against complement acts at multiple steps in the pathway by mechanisms that are not fully understood. Here we identify outer membrane protein P5 as an essential factor in serum resistance of both H. influenzae strain Rd and nontypeable H. influenzae (NTHi) clinical isolate NT127. P5 was essential for resistance of Rd and NT127 to complement in pooled human serum. Further investigation determined that P5 expression decreased cell surface binding of IgM, a potent activator of the classical pathway of complement, to both Rd and NT127. Additionally, P5 expression was required for NT127 to bind factor H (fH), an important inhibitor of alternative pathway (AP) activation. Collectively, the results obtained in this work highlight the ability of H. influenzae to utilize a single protein to perform multiple protective functions for evading host immunity.
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Khan S, Reddy S. Haemophilus influenzae infection of a prosthetic knee joint in a patient with CLL: a vaccine preventable disease. BMJ Case Rep 2013; 2013:bcr2013010307. [PMID: 24252835 PMCID: PMC3841430 DOI: 10.1136/bcr-2013-010307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 71-year-old man was admitted with a 2-day history of the hot and swollen right knee in December 2012. He had undergone a primary cemented right total knee replacement (TKR) in 2002. He also had a history of chronic lymphatic leukaemia (CLL), haemolytic anaemia and splenomegaly, and was in partial remission following chemotherapy in 2008. He underwent arthroscopic washout of right TKR on admission. Blood cultures on admission and joint fluid specimen grew Haemophilus influenzae (Hi). The isolate was identified as a non-encapsulated Hi strain by the reference laboratory. Non-encapsulated Hi strains rarely cause invasive disease. CLL with splenomegaly may have predisposed our patient to severe invasive disease. A recently licensed 10-valent pneumococcal vaccine conjugated to the immunogenic outer membrane protein D of Hi could potentially prevent invasive Hi disease. Routine vaccination should be considered in all patients with prosthetic joints and predisposing comorbidities.
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Affiliation(s)
- Sheema Khan
- Department of Microbiology, East Kent University Hospital NHS Foundation Trust, Ashford, UK
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15
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Ladhani SN, Collins S, Vickers A, Litt DJ, Crawford C, Ramsay ME, Slack MPE. Invasive Haemophilus influenzae serotype e and f disease, England and Wales. Emerg Infect Dis 2013; 18:725-32. [PMID: 22515912 PMCID: PMC3358072 DOI: 10.3201/eid1805.111738] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Incidence of serotype e was 3-fold lower than serotype f, but it caused more severe clinical disease.
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17
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Wroblewski D, Halse TA, Hayes J, Kohlerschmidt D, Musser KA. Utilization of a real-time PCR approach for Haemophilus influenzae serotype determination as an alternative to the slide agglutination test. Mol Cell Probes 2012. [PMID: 23195602 DOI: 10.1016/j.mcp.2012.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Our laboratory has developed a simple two-step multiplex real-time PCR for use on isolates of Haemophilus influenzae for molecular serotype identification and the detection of capsular gene targets. The assay consists of a 2-plex real-time PCR targeting the capsule transport gene (bexA), and serotype b specific gene (bcsB), and a 5-plex real-time PCR detecting serotypes a, c, d, e, and f targeting Region II serotype-specific genes. Both real-time PCR assays are highly sensitive (<8 CFU) for all serotypes and 100% specific when tested by a panel of more than 40 bacterial organisms. A retrospective study of 214 isolates received between 1998 and 2011 were tested and compared against the traditional slide agglutination test (SAT) resulting in 100% concordance. We demonstrate that this two-step real-time PCR approach is more sensitive than previously published PCR assays and provides a simple alternative to the SAT. Reliable, rapid and sensitive H. influenzae serotyping is critical for identifying new emerging strains for epidemiological surveillance.
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Affiliation(s)
- Danielle Wroblewski
- Wadsworth Center, New York State Department of Health, PO Box 22002, Albany, NY 12201-2002, USA
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18
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Livorsi DJ, Macneil JR, Cohn AC, Bareta J, Zansky S, Petit S, Gershman K, Harrison LH, Lynfield R, Reingold A, Schaffner W, Thomas A, Farley MM. Invasive Haemophilus influenzae in the United States, 1999-2008: epidemiology and outcomes. J Infect 2012; 65:496-504. [PMID: 22902945 DOI: 10.1016/j.jinf.2012.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/06/2012] [Accepted: 08/07/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Introduction of the Haemophilus influenzae type b (Hib) conjugate vaccine has resulted in a dramatic reduction of Hib disease in the U.S. and an increase in the relative importance of infections caused by nontypeable strains. The current project describes the characteristics and clinical outcomes of pediatric and adult patients with invasive H. influenzae (HI) and, through multivariable analysis, identifies risk factors for in-hospital mortality. METHODS HI cases were identified during 1999-2008 through active surveillance as part of active bacterial core surveillance (ABCs). Multivariable analysis was performed with logistic regression to identify factors predictive of in-hospital death. RESULTS 4839 cases of HI were identified from 1999-2008. Children accounted for 17.1% of cases and adults 82.9%. Underlying conditions were present in 20.7% of children and 74.8% of adults. In-hospital mortality was highest in cases ≥65 years (21.9%) and <3 months (16.2%). The risk of in-hospital death in children <1 year was higher among those who were prematurely-born (<28 weeks, OR 7.1, 95% CI 3.2-15.6; 28-36 weeks OR 2.1, 95% CI 0.9-4.8) and, among children aged 1-17 years, higher in those with healthcare-associated onset and dialysis (OR 5.66, 95% CI 1.84-17.39; OR 18.11, 95% CI 2.77-118.65). In adults, age ≥40 was associated with death in nontypeable, but not encapsulated, infections. Infections with nontypeable strains increased the risk of death in cases ≥65 years (OR 1.81, 95% CI 1.31-2.52). Healthcare-associated HI, bacteremia without identifiable focus, bacteremic pneumonia, associated cirrhosis, cerebrovascular accident, dialysis, heart failure, and non-hematologic malignancy also increased the risk of death in adults. CONCLUSION Prematurity in infants, advanced age and certain chronic diseases in adults were associated with an increased risk of in-hospital death. Nontypeable HI was associated with higher mortality in the elderly.
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Affiliation(s)
- Daniel J Livorsi
- Department of Medicine, Emory University School of Medicine, The Atlanta VA Medical Center, 1670 Clairmont Road, Mail Code 151-ID, Atlanta, GA 30333, USA.
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The burden of nonencapsulated Haemophilus influenzae in children and potential for prevention. Curr Opin Infect Dis 2012; 25:266-72. [PMID: 22561999 DOI: 10.1097/qco.0b013e32835310a4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW In countries with established Haemophilus influenzae serotype b (Hib) immunization programmes, nonencapsulated H. influenzae (ncHi) is responsible for most invasive H. influenzae infections across all age groups and is associated with higher case fatality. A pneumococcal conjugate vaccine has recently been licensed, which may potentially also protect against invasive H. influenzae infections. RECENT FINDINGS Invasive ncHi disease is uncommon in childhood but has a much higher incidence in the first month of life. Most neonates with invasive ncHi infections are born prematurely and develop septicaemia in the first 48 h of life which can be fatal. After this period, invasive ncHi incidence falls rapidly and remains low throughout childhood. Most infants and children who develop invasive ncHi disease have significant underlying comorbidities, particularly neurological disease, malignancy and other conditions requiring immunosuppressive therapy. Although characteristically associated with respiratory tract infections, at least a quarter of invasive ncHi infections present with meningitis. SUMMARY A vaccine against ncHi could have an important preventive role in children with comorbidities. Future studies should focus on assessing specific risk factors for neonatal and childhood ncHi disease and long-term outcomes of children with invasive ncHi meningitis.
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A clonal group of nontypeable Haemophilus influenzae with two IgA proteases is adapted to infection in chronic obstructive pulmonary disease. PLoS One 2011; 6:e25923. [PMID: 21998721 PMCID: PMC3187821 DOI: 10.1371/journal.pone.0025923] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 09/13/2011] [Indexed: 11/19/2022] Open
Abstract
Strains of nontypeable Haemophilus influenzae show enormous genetic heterogeneity and display differential virulence potential in different clinical settings. The igaB gene, which encodes a newly identified IgA protease, is more likely to be present in the genome of COPD strains of H. influenzae than in otitis media strains. Analysis of igaB and surrounding sequences in the present study showed that H. influenzae likely acquired igaB from Neisseria meningitidis and that the acquisition was accompanied by a ~20 kb genomic inversion that is present only in strains that have igaB. As part of a long running prospective study of COPD, molecular typing of H. influenzae strains identified a clonally related group of strains, a surprising observation given the genetic heterogeneity that characterizes strains of nontypeable H. influenzae. Analysis of strains by 5 independent methods (polyacrylamide gel electrophoresis, multilocus sequence typing, igaB gene sequences, P2 gene sequences, pulsed field gel electrophoresis) established the clonal relationship among the strains. Analysis of 134 independent strains collected prospectively from a cohort of adults with COPD demonstrated that ~10% belonged to the clonal group. We conclude that a clonally related group of strains of nontypeable H. influenzae that has two IgA1 protease genes (iga and igaB) is adapted for colonization and infection in COPD. This observation has important implications in understanding population dynamics of H. influenzae in human infection and in understanding virulence mechanisms specifically in the setting of COPD.
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van Wessel K, Rodenburg GD, Veenhoven RH, Spanjaard L, van der Ende A, Sanders EAM. Nontypeable Haemophilus influenzae Invasive Disease in the Netherlands: A Retrospective Surveillance Study 2001-2008. Clin Infect Dis 2011; 53:e1-7. [DOI: 10.1093/cid/cir268] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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ArcA-regulated glycosyltransferase lic2B promotes complement evasion and pathogenesis of nontypeable Haemophilus influenzae. Infect Immun 2011; 79:1971-83. [PMID: 21357723 DOI: 10.1128/iai.01269-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Signaling mechanisms used by Haemophilus influenzae to adapt to conditions it encounters during stages of infection and pathogenesis are not well understood. The ArcAB two-component signal transduction system controls gene expression in response to respiratory conditions of growth and contributes to resistance to bactericidal effects of serum and to bloodstream infection by H. influenzae. We show that ArcA of nontypeable H. influenzae (NTHI) activates expression of a glycosyltransferase gene, lic2B. Structural comparison of the lipooligosaccharide (LOS) of a lic2B mutant to that of the wild-type strain NT127 revealed that lic2B is required for addition of a galactose residue to the LOS outer core. The lic2B gene was crucial for optimal survival of NTHI in a mouse model of bacteremia and for evasion of serum complement. The results demonstrate that ArcA, which controls cellular metabolism in response to environmental reduction and oxidation (redox) conditions, also coordinately controls genes that are critical for immune evasion, providing evidence that NTHI integrates redox signals to regulate specific countermeasures against host defense.
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Resman F, Ristovski M, Ahl J, Forsgren A, Gilsdorf JR, Jasir A, Kaijser B, Kronvall G, Riesbeck K. Invasive disease caused by Haemophilus influenzae in Sweden 1997-2009; evidence of increasing incidence and clinical burden of non-type b strains. Clin Microbiol Infect 2011; 17:1638-45. [PMID: 21054663 DOI: 10.1111/j.1469-0691.2010.03417.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae non-type b has recently been reported. Non-type b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates (n = 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3 million individuals were identified. All available isolates were serotyped by PCR (n = 250). We observed a statistically significant increase in the incidence of invasive H. influenzae disease, ascribed to non-typeable H. influenzae (NTHi) and encapsulated strains type f (Hif) in mainly individuals >60 years of age. The medical reports from a subset of 136 cases of invasive Haemophilus disease revealed that 48% of invasive NTHi cases and 59% of invasive Hif cases, respectively, met the criteria of severe sepsis or septic shock according to the ACCP/SCCM classification of sepsis grading. One-fifth of invasive NTHi cases and more than one-third of invasive Hif cases were admitted to intensive care units. Only 37% of patients with invasive non-type b disease had evidence of immunocompromise, of which conditions related to impaired humoral immunity was the most common. The clinical burden of invasive non-type b H. influenzae disease, measured as days of hospitalization/100 000 individuals at risk and year, increased significantly throughout the study period.
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Affiliation(s)
- F Resman
- Medical Microbiology, Department of Laboratory Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
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Meningitis and septicemia caused by nontypeable Haemophilus influenzae in a previously healthy 2-year-old girl. J Infect Chemother 2011; 17:559-62. [PMID: 21286774 PMCID: PMC3156912 DOI: 10.1007/s10156-011-0213-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 12/28/2010] [Indexed: 11/30/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) commonly colonizes the upper respiratory tract of children and causes otitis media, sinusitis, and bronchitis. Invasive NTHi diseases such as meningitis and septicemia have rarely been reported, especially in children with underlying predisposing conditions such as head trauma and immune compromise. However, we report a previously healthy 2-year-old girl who developed meningitis and septicemia caused by NTHi biotype ΙΙΙ. She was treated with dexamethasone, meropenem, and ceftriaxone, and recovered uneventfully. We wish to emphasize that NTHi should be borne in mind as a potential pathogen that can cause meningitis and septicemia, even in previously healthy children.
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Calado R, Betencourt C, Gonçalves H, Cristino N, Calhau P, Lavado PB. Complicated Meningitis caused by a rare serotype of Haemophilus influenzae in Portugal. Diagn Microbiol Infect Dis 2011; 69:111-3. [DOI: 10.1016/j.diagmicrobio.2010.08.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/24/2010] [Accepted: 08/29/2010] [Indexed: 10/18/2022]
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Talbird SE, Ismaila AS, Taylor TN. A steady-state, population-based model to estimate the direct and indirect effects of pneumococcal vaccines. Vaccine 2010; 28 Suppl 6:G3-13. [DOI: 10.1016/j.vaccine.2010.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Talbird SE, Taylor TN, Caporale J, Ismaila AS, Gomez J. Residual economic burden of Streptococcus pneumoniae- and nontypeable Haemophilus influenzae- associated disease following vaccination with PCV-7: A multicountry analysis. Vaccine 2010; 28 Suppl 6:G14-22. [DOI: 10.1016/j.vaccine.2010.06.080] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ladhani S, Slack MPE, Heath PT, von Gottberg A, Chandra M, Ramsay ME. Invasive Haemophilus influenzae Disease, Europe, 1996-2006. Emerg Infect Dis 2010; 16:455-63. [PMID: 20202421 PMCID: PMC3322004 DOI: 10.3201/eid1603.090290] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An international collaboration was established in 1996 to monitor the impact of routine Haemophilus influenzae type b (Hib) vaccination on invasive H. influenzae disease; 14 countries routinely serotype all clinical isolates. Of the 10,081 invasive H. influenzae infections reported during 1996-2006, 4,466 (44%, incidence 0.28 infections/100,000 population) were due to noncapsulated H. influenzae (ncHi); 2,836 (28%, 0.15/100,000), to Hib; and 690 (7%, 0.036/100,000), to non-b encapsulated H. influenzae. Invasive ncHi infections occurred in older persons more often than Hib (median age 58 years vs. 5 years, p<0.0001) and were associated with higher case-fatality ratios (12% vs. 4%, p<0.0001), particularly in infants (17% vs. 3%, p<0.0001). Among non-b encapsulated H. influenzae, types f (72%) and e (21%) were responsible for almost all cases; the overall case-fatality rate was 9%. Thus, the incidence of invasive non-type b H. influenzae is now higher than that of Hib and is associated with higher case fatality.
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Modeling the impact of a new vaccine on pneumococcal and nontypable Haemophilus influenzae diseases: a new simulation model. Clin Ther 2010; 31:2152-69. [PMID: 19922887 DOI: 10.1016/j.clinthera.2009.10.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2009] [Indexed: 11/23/2022]
Abstract
BACKGROUND A heptavalent pneumococcal conjugate vaccine (PCV-7) is available to immunize infants against pneumococcal disease. However, a recently developed vaccine, pneumococcal nontypable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV), has recently been licensed. PHiD-CV contains 3 additional Streptococcus pneumoniae serotypes and may provide protection against nontypable H influenzae (NTHi) infection. New health economic models are required to model the impact of PHiD-CV and compare its effectiveness with PCV-7. OBJECTIVES The aim of this article was to design a model capable of projecting the pneumococcal and NTHi disease burden on the entire UK population under different schedules of PCV-7 and PHiD-CV. This model should also be capable of modeling the net indirect effect of vaccination (ie, the sum of serotype replacement and herd protection). METHODS A static, deterministic, age-compartmental model was created based on published information and the input of a board of experts in pneumococcal disease. The model presents results from both a payer-based and societal perspective. A 1-way sensitivity analysis was used to demonstrate the robustness of the model. Key parameters included the case fatality ratio for bacteremia, the hospitalization rate for acute otitis media (AOM), and parameters surrounding the extent of the net indirect effect of vaccination. RESULTS Excluding net indirect effect, 325 cases of invasive pneumococcal disease (IPD), 619 hospitalizations for pneumonia, and 9016 general practitioner visits for AOM would be prevented annually with the current PCV-7 2 + 1 program. These numbers would increase to 374, 755, and 30,920, respectively, using a PHiD-CV 2 + 1 regimen, or to 503, 994, and 47,180 using a PHiD-CV 3 + 1 regimen. When a net indirect effect of 38% is considered, health benefits could be much larger; 2417, 2451, and 3045 IPD cases would be prevented in the 3 scenarios, respectively. CONCLUSIONS It is predicted that any vaccination program in the United Kingdom would have a striking impact on the incidence of all outcomes analyzed. A PHiD-CV 3 + 1 schedule is predicted to have a greater effect than PCV-7 in all scenarios. While the primary purpose of vaccination would be to prevent IPD and pneumonia hospitalizations, an additional benefit would be a noticeable reduction in AOM incidence. While the predictions made by the model were based on informed reasoning, all of its projected estimations remain approximations that are dependent on the inputs used to configure it, a limitation that is common to all simulation models.
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Kalies H, Siedler A, Gröndahl B, Grote V, Milde-Busch A, von Kries R. Invasive Haemophilus influenzae infections in Germany: impact of non-type b serotypes in the post-vaccine era. BMC Infect Dis 2009; 9:45. [PMID: 19379490 PMCID: PMC2678273 DOI: 10.1186/1471-2334-9-45] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Accepted: 04/20/2009] [Indexed: 11/16/2022] Open
Abstract
Background Haemophilus influenzae type b (Hib) vaccination led to a significant decrease in invasive bacterial infections in children. The aim of this study was to assess a potential shift to more non-type b invasive infections in a population with high Hib vaccination coverage and to compare the burden of suffering between children with Hib, capsulated non-b and non-capsulated Hi infections. Methods Cases with confirmed invasive Hi infections were ascertained through two independent nationwide active surveillance systems in 1998–2005. Information on possible predisposing conditions and clinical information was available from 2001 onwards. Results The total number of reported non-type b Hi cases varied between 10 cases in 1998, 27 in 2000 and 14 in 2005. In each year, non-capsulated serotypes outnumbered capsulated non-type b ones. 192 cases were detected in 2001–2005, more than one half was non-type b and 88% of the non-type b cases were non-capsulated. For cases with Hib/capsulated non-type b infections the most common clinical presentation was meningitis (67% each); 89%/78% had no potential predisposing condition, 75%/72% completely recovered from disease and 6% (each) died. In contrast, meningitis was diagnosed in 34% of the non-capsulated Hi infections, septicaemia in 28% and pneumonia 21%; 62% had no potential predisposing condition, 83% completely recovered and 3% died. Conclusion There was no increase in non-type b Hi invasive infections during 8 years of active surveillance in Germany. Invasive disease due to non-type b Hi is not confined to children with risk factors. In patients with capsulated non-type b Hi infections the proportion of meningitis cases is similar to Hib, but double as high as in non-capsulated Hi.
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Affiliation(s)
- Helen Kalies
- Department Epidemiology, Institute for Social Pediatrics and Adolescent Medicine, Ludwig-Maximilians-University, Munich, Germany.
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Nanoscale structural and mechanical properties of nontypeable Haemophilus influenzae biofilms. J Bacteriol 2009; 191:2512-20. [PMID: 19218382 DOI: 10.1128/jb.01596-08] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nontypeable Haemophilus influenzae (NTHI) bacteria are commensals in the human nasopharynx, as well as pathogens associated with a spectrum of acute and chronic infections. Two important factors that influence NTHI pathogenicity are their ability to adhere to human tissue and their ability to form biofilms. Extracellular polymeric substances (EPS) and bacterial appendages such as pili critically influence cell adhesion and intercellular cohesion during biofilm formation. Structural components in the outer cell membrane, such as lipopolysaccharides, also play a fundamental role in infection of the host organism. In spite of their importance, these pathogenic factors are not yet well characterized at the nanoscale. Here, atomic force microscopy (AFM) was used in aqueous environments to visualize structural details, including probable Hif-type pili, of live NTHI bacteria at the early stages of biofilm formation. Using single-molecule AFM-based spectroscopy, the molecular elasticities of lipooligosaccharides present on NTHI cell surfaces were analyzed and compared between two strains (PittEE and PittGG) with very different pathogenicity profiles. Furthermore, the stiffness of single cells of both strains was measured and subsequently their turgor pressure was estimated.
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Association of IS1016 with the hia adhesin gene and biotypes V and I in invasive nontypeable Haemophilus influenzae. Infect Immun 2008; 76:5221-7. [PMID: 18794287 DOI: 10.1128/iai.00672-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A subset of invasive nontypeable Haemophilus influenzae (NTHI) strains has evidence of IS1016, an insertion element associated with division I H. influenzae capsule serotypes. We examined IS1016-positive invasive NTHI isolates collected as part of Active Bacterial Core Surveillance within the Georgia Emerging Infections Program for the presence or absence of hmw1 and hmw2 (two related adhesin genes that are common in NTHI but absent in encapsulated H. influenzae) and hia (homologue of hsf, an encapsulated H. influenzae adhesin gene). Isolates were serotyped using slide agglutination, confirmed as NTHI strains using PCR capsule typing, and biotyped. Two hundred twenty-nine invasive NTHI isolates collected between August 1998 and December 2006 were screened for IS1016; 22/229 (9.6%) were positive. Nineteen of 201 previously identified IS1016-positive invasive NTHI isolates collected between January 1989 and July 1998 were also examined. Forty-one IS1016-positive and 56 randomly selected IS1016-negative invasive NTHI strains were examined. The hia adhesin was present in 39 of 41 (95%) IS1016-positive NTHI strains and 1 of 56 (1.8%) IS1016-negative NTHI strains tested; hmw (hmw1, hmw2, or both) was present in 50 of 56 (89%) IS1016-negative NTHI isolates but in only 5 of 41 (12%; all hmw2) IS1016-positive NTHI isolates. IS1016-positive NTHI strains were more often biotype V (P < 0.001) or biotype I (P = 0.04) than IS1016-negative NTHI strains, which were most often biotype II. Pulsed-field gel electrophoresis revealed the expected genetic diversity of NTHI with some clustering based on IS1016, hmw or hia, and biotypes. A significant association of IS1016 with biotypes V and I and the presence of hia adhesins was found among invasive NTHI. IS1016-positive NTHI strains may represent a unique subset of NTHI strains, with characteristics more closely resembling those of encapsulated H. influenzae.
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Purulent pericarditis caused by nontypeable Haemophilus influenzae in a pediatric patient. Diagn Microbiol Infect Dis 2008; 62:113-5. [DOI: 10.1016/j.diagmicrobio.2007.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 10/02/2007] [Accepted: 10/10/2007] [Indexed: 11/15/2022]
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Sekiya Y, Eguchi M, Nakamura M, Ubukata K, Omura S, Matsui H. Comparative efficacies of different antibiotic treatments to eradicate nontypeable Haemophilus influenzae infection. BMC Infect Dis 2008; 8:15. [PMID: 18254980 PMCID: PMC2276502 DOI: 10.1186/1471-2334-8-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Accepted: 02/07/2008] [Indexed: 12/03/2022] Open
Abstract
Background Nonencapsulated and nontypeable Haemophilus influenzae (NTHi) is a major cause of human respiratory tract infections. Some strains of NTHi can cause invasive diseases such as septicemia and meningitis, even if H. influenzae is not generally considered to be an intracellular pathogen. There have been very few reports about the therapeutic efficacy of antibiotics against respiratory tract infection caused by NTHi in mice because it is difficult for H. influenzae to infect mice. Therefore, we evaluated the efficacy of antibiotics against NTHi in both a cell culture model and a mouse model of infection. Methods We used six strains of NTHi isolated from adult patients with chronic otitis media, namely three β-lactamase-negative ampicillin (AMP)-resistant (BLNAR) strains and three β-lactamase-negative AMP-susceptible (BLNAS) strains, to evaluate the efficacy of AMP, cefcapene (CFPN), levofloxacin (LVX), clarithromycin (CLR), and azithromycin (AZM) in both a cell culture infection model and a mouse infection model. In the cell culture infection model, strains that invade A549 human alveolar epithelial cells were treated with each antibiotic (1 μg/ml). In the mouse infection model, female C57BL/6 mice were intraperitoneally injected with cyclophosphamide (200 mg/kg) three days before intranasal infection with 1 × 109 colony-forming units (CFU) of NTHi and on the day of infection. After infection, the mice were orally administered each antibiotic three times daily for three days, except for AZM, which was administered once daily for three days, at a dose of 100 mg/kg/day. Results In the cell culture infection model, it was found that two BLNAR strains were able to enter the cell monolayers by the process of macropinocytosis, and treatment with LVX yielded good bactericidal activity against both strains inside the cells. In the mouse infection model, no bacteria were detected by means of plating the lung homogenates of LVX-treated mice at day 4 after infection, while more than 105 CFU of bacteria per tissue sample were detected in nontreated mice. Conclusion Our findings show the outcome and rich benefits of fluoroquinolone treatment of respiratory infections caused by either invasive or noninvasive BLNAR strains of NTHi.
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Affiliation(s)
- Yukie Sekiya
- Center for Basic Research, The Kitasato Institute, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8642, Japan.
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The periplasmic disulfide oxidoreductase DsbA contributes to Haemophilus influenzae pathogenesis. Infect Immun 2008; 76:1498-508. [PMID: 18212083 DOI: 10.1128/iai.01378-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Haemophilus influenzae is an obligate human pathogen that persistently colonizes the nasopharynx and causes disease when it invades the bloodstream, lungs, or middle ear. Proteins that mediate critical interactions with the host during invasive disease are likely to be secreted. Many secreted proteins require addition of disulfide bonds by the DsbA disulfide oxidoreductase for activity or stability. In this study, we evaluated the role in H. influenzae pathogenesis of DsbA, as well as HbpA, a substrate of DsbA. Mutants of H. influenzae Rd and type b strain Eagan having nonpolar deletions of dsbA were attenuated for bacteremia in animal models, and complemented strains exhibited virulence equivalent to that of the parental strains. Comparison of predicted secreted proteins in H. influenzae to known DsbA substrates in other species revealed several proteins that could contribute to the role of dsbA in virulence. One candidate, the heme transport protein, HbpA, was examined because of the importance of exogenous heme for aerobic growth of H. influenzae. The presence of a dsbA-dependent disulfide bond in HbpA was verified by an alkylation protection assay, and HbpA was less abundant in a dsbA mutant. The hbpA mutant exhibited reduced bacteremia in the mouse model, and complementation restored its in vivo phenotype to that of the parental strain. These results indicate that dsbA is required in vivo and that HbpA and additional DsbA-dependent factors are likely to participate in H. influenzae pathogenesis.
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Invasive infections caused by haemophilus influenzae serotypes in twelve Canadian IMPACT centers, 1996-2001. Pediatr Infect Dis J 2007; 26:1025-31. [PMID: 17984810 DOI: 10.1097/inf.0b013e31812f4f5b] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Haemophilus influenzae type b (Hib) immunization has changed the epidemiology of pediatric bacterial invasive disease. We describe the epidemiology of H. influenzae invasive infections in 12 Canadian pediatric tertiary care [Immunization Monitoring Program, ACTive (IMPACT)] centers during the era of universal immunization against this pathogen. METHODS Children with positive cultures for H. influenzae serotypes a to f (Hia to Hif) and nontypable H. influenzae from sterile sites were identified from the laboratory records at 12 IMPACT centers from January 1, 1996 to December 31, 2001. Hospital records were retrospectively reviewed for demographic and clinical information. RESULTS Of 166 H. influenzae cases, 58 (35%) were caused by Hib, 89 (54%) by non-b serotypes, and 19 (11%) were not serotyped. The non-b serotypes included: 25 Hia (28%), 4 Hid (4%), 2 Hie (2%), 11 Hif (12%), and 47 were nontypable isolates (53%). For patients with Hib and Hia infection, meningitis was the most common presentation, accounting for 40% and 52% respectively, whereas the most common presentation for nontypable serotypes was pneumonia, seen in 43% of cases. Epiglottitis was associated mainly with Hib. Aboriginal ethnicity was an important risk factor for Hia cases, accounting for 76% of patients with infections caused by this serotype. Mean duration of hospitalization, need for admission to a pediatric intensive care unit, and case fatality rates were similar for the cases because of Hib, Hia, Hif, and nontypable serotypes. CONCLUSIONS In 1996-2001, two-thirds of H. influenzae invasive disease in the 12 IMPACT centers was caused by non-b serotypes, which were associated with significant morbidity and mortality.
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Kunze W, Müller L, Kilian M, Schuhmann MU, Baumann L, Handrick W. Recurrent posttraumatic meningitis due to nontypable Haemophilus influenzae: case report and review of the literature. Infection 2007; 36:74-7. [PMID: 17926006 DOI: 10.1007/s15010-007-6048-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Accepted: 01/22/2007] [Indexed: 11/26/2022]
Abstract
We report a case of relapsing Haemophilus influenzae meningitis in a boy at the age of nearly 3 years and 4.2 years who had been successfully vaccinated against H. influenzae serotype b (Hib). The pathogen was a nonencapsulated (nontypable) H. influenzae strain of biotypes III and VI, respectively. A rhinobasal impalement injury with development of a posttraumatic encephalocele is considered to be the predisposing condition. Review of the literature reveals that in patients systemically infected by nonencapsulated H. influenzae strains predisposing factors such as cerebrospinal fluid-shunts, implants and traumas are often found. To obtain further information on potential new disease patterns H. influenzae isolates from cerebrospinal fluid should be examined for capsule production and, if relevant, further characterized by capsular typing.
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Affiliation(s)
- W Kunze
- Department of Pediatrics, Community Hospital Wurzen, Germany, Kutusowstr. 70, 04808, Wurzen, Germany.
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Satola SW, Collins JT, Napier R, Farley MM. Capsule gene analysis of invasive Haemophilus influenzae: accuracy of serotyping and prevalence of IS1016 among nontypeable isolates. J Clin Microbiol 2007; 45:3230-8. [PMID: 17699642 PMCID: PMC2045354 DOI: 10.1128/jcm.00794-07] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We evaluated the accuracy of serologic capsule typing by analyzing capsule genes and related markers among invasive Haemophilus influenzae isolates before and after the introduction of H. influenzae serotype b (Hib) conjugate vaccines. Three hundred and sixty invasive H. influenzae isolates were collected as part of Active Bacterial Core surveillance within the Georgia Emerging Infections Program between 1 January 1989 and 31 July 1998. All isolates were biotyped, serotyped by slide agglutination serotyping (SAST), and evaluated using PCR capsule typing. Nontypeable H. influenzae (NTHi) isolates were probed with Hib cap-gene-containing plasmid pUO38 and with IS1016; a subset was examined with phosphoglucose isomerase (pgi) genotyping and pulsed-field gel electrophoresis (PFGE). Discrepancies between SAST and PCR capsule typing were found for 64/360 (17.5%) of the isolates; 48 encapsulated by SAST were NTHi by PCR, 8 NTHi by SAST were encapsulated by PCR, 6 encapsulated by SAST were a different capsule type by PCR, and 2 encapsulated by SAST were capsule-deficient Hib variants (Hib-minus). None of the PCR-confirmed NTHi isolates demonstrated homology with residual capsule gene sequences; 19/201 (9.5%) had evidence of IS1016, an insertion element associated with division I H. influenzae capsule serotypes. The majority of IS1016-positive NTHi were biotypes I and V and showed some genetic relatedness by PFGE. In conclusion, PCR capsule typing was more accurate than SAST and Hib-minus variants were rare. IS1016 was present in 9.5% of NTHi isolates, suggesting that this subset may be more closely related to encapsulated organisms. A better understanding of NTHi may contribute to vaccine development.
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Affiliation(s)
- Sarah W Satola
- Atlanta Veterans Affairs Medical Center, Medical Research Service 151, 1670 Clairmont Rd., Decatur, GA 30033, USA
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40
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Cardines R, Giufrè M, Mastrantonio P, Ciofi degli Atti ML, Cerquetti M. Nontypeable Haemophilus influenzae meningitis in children: phenotypic and genotypic characterization of isolates. Pediatr Infect Dis J 2007; 26:577-82. [PMID: 17596797 DOI: 10.1097/inf.0b013e3180616715] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND With the decline in the incidence of invasive Haemophilus influenzae type b disease as result of routine immunization of infants, the potential emergence of nontypeable H. influenzae (NTHi) strains as important pathogens has been suggested. METHODS From June 1997 to July 2006, 9 cases of NTHi meningitis in children aged < or =60 months were detected. The 9 NTHi isolates were characterized. Antimicrobial susceptibility patterns were determined by E-test. The transpeptidase domain of penicillin binding protein 3 of a beta-lactamase negative ampicillin-resistant strain was sequenced. Genetic relatedness among isolates was assessed by pulsed field gel electrophoresis and by multilocus sequence typing. The presence of HMW and Hia adhesins and hemagglutinating fimbriae was investigated by PCR and Western Blotting. RESULTS The 9 cases of NTHi meningitis did not occur in specific risk groups, except for one patient. Of the 9 NTHi isolates, 2 were beta-lactamase producers and 1 showed the beta-lactamase negative ampicillin-resistant phenotype. Sequencing of the penicillin binding protein 3 revealed novel amino acid substitutions. A high degree of genetic diversity among isolates was demonstrated by pulsed field gel electrophoresis. Multilocus sequence genotyping confirmed that the 9 NTHi isolates did not belong to related phylogenetic clusters. HMW adhesins were found in 2 isolates, and 5 strains possessed Hia. No hemagglutinating fimbriae were detected, even though 2 isolates contained hifA gene sequences. CONCLUSION NTHi isolates from cases of meningitis in children are genetically diverse. Distribution of adhesins among the isolates we examined is unusual: most strains express Hia that generally occurs in a minority of strains in NTHi, suggesting that this adhesin may play a role in virulence mechanisms of NTHi causing meningitis.
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Affiliation(s)
- Rita Cardines
- Department of Infectious, Parasitic and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
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Wong SMS, Alugupalli KR, Ram S, Akerley BJ. The ArcA regulon and oxidative stress resistance in Haemophilus influenzae. Mol Microbiol 2007; 64:1375-90. [PMID: 17542927 PMCID: PMC1974803 DOI: 10.1111/j.1365-2958.2007.05747.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2007] [Indexed: 01/11/2023]
Abstract
Haemophilus influenzae transits between niches within the human host that are predicted to differ in oxygen levels. The ArcAB two-component signal transduction system controls gene expression in response to respiratory conditions of growth and has been implicated in bacterial pathogenesis, yet the mechanism is not understood. We undertook a genome-scale study to identify genes of the H. influenzae ArcA regulon. Deletion of arcA resulted in increased anaerobic expression of genes of the respiratory chain and of H. influenzae's partial tricarboxylic acid cycle, and decreased anaerobic expression levels of genes of polyamine metabolism, and iron sequestration. Deletion of arcA also conferred a susceptibility to transient exposure to hydrogen peroxide that was greater following anaerobic growth than after aerobic growth. Array data revealed that the dps gene, not previously assigned to the ArcA modulon in bacteria, exhibited decreased expression in the arcA mutant. Deletion of dps resulted in hydrogen peroxide sensitivity and complementation restored resistance, providing insight into the previously uncharacterized mechanism of arcA-mediated H(2)O(2) resistance. The results indicate a role for H. influenzae arcA and dps in pre-emptive defence against transitions from growth in low oxygen environments to aerobic exposure to hydrogen peroxide, an antibacterial oxidant produced by phagocytes during infection.
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Affiliation(s)
- Sandy M S Wong
- Department of Molecular Genetics and Microbiology, University of Massachusetts Medical SchoolWorcester, MA 01655, USA.
| | - Kishore R Alugupalli
- Department of Molecular Genetics and Microbiology, University of Massachusetts Medical SchoolWorcester, MA 01655, USA.
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical SchoolWorcester, MA 01605, USA.
| | - Brian J Akerley
- Department of Molecular Genetics and Microbiology, University of Massachusetts Medical SchoolWorcester, MA 01655, USA.
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42
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Ho DK, Ram S, Nelson KL, Bonthuis PJ, Smith AL. lgtC expression modulates resistance to C4b deposition on an invasive nontypeable Haemophilus influenzae. THE JOURNAL OF IMMUNOLOGY 2007; 178:1002-12. [PMID: 17202363 DOI: 10.4049/jimmunol.178.2.1002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have previously shown that C3 binding to serum-resistant nontypeable Haemophilus influenzae (NTHi) strain R2866 is slower than C3 binding to a serum-sensitive strain. Ab-dependent classical pathway activation is required for complement-dependent killing of NTHi. To further characterize the mechanism(s) of serum resistance of R2866, we compared binding of complement component C4b to R2866 with a serum-sensitive variant, R3392. We show that C4b binding to R2866 relative to R3392 was delayed, suggesting regulation of the classical pathway of complement. Increased C4b deposition on R3392 was independent of the amount and subclass of Ab binding, suggesting that an impediment to C4b binding existed on R2866. Immunoblotting and mass spectrometry indicated that lipooligosaccharide and outer membrane proteins P2 and P5 were targets for C4b. P2 and P5 sequences and expression levels were similar in both strains. Insertional inactivation of the phase-variable lipooligosaccharide biosynthesis gene lgtC in R2866 augmented C4b deposition to levels seen with R3392 and rendered the bacteria sensitive to serum and whole blood. These results suggest a direct role of lgtC expression in the inhibition of C4b deposition and consequent serum resistance of R2866. Alteration of surface glycans of NTHi may be a critical event in determining the ability of a strain to evade host defenses and cause disseminated infection.
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Affiliation(s)
- Derek K Ho
- Department of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle, WA 98195, USA
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43
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Tsang RSW, Mubareka S, Sill ML, Wylie J, Skinner S, Law DKS. Invasive Haemophilus influenzae in Manitoba, Canada, in the postvaccination era. J Clin Microbiol 2006; 44:1530-5. [PMID: 16597886 PMCID: PMC1448631 DOI: 10.1128/jcm.44.4.1530-1535.2006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fifty-two Haemophilus influenzae isolates from patients with invasive disease in the province of Manitoba, Canada, were examined for serotype, biotype, genotype, and antibiotic susceptibility. Half of the 52 isolates were found to be serotype a, and 38.5% (20 isolates) were found to be nonserotypeable (NST). There were only three serotype b strains and one each for serotypes c, d, and f. All 26 serotype a isolates belonged to biotype II and demonstrated identical or highly similar DNA fingerprints by pulsed-field gel electrophoresis. An analysis of these isolates by multilocus sequence typing showed that they belong to the clonal complex ST-23. While 69% (18 of 26) of the serotype a cases were found in males, only 9 (45%) of the 20 patients with NST isolates were males. Twenty (77%) of the 26 serotype a isolates were from patients who were </=24 months old. Twelve (63%) of the NST isolates were from adult or adolescent patients. In contrast to the clonal nature of serotype a isolates, the 20 NST isolates were found to belong to 18 different sequence types. Most of these 18 different sequence types were unrelated to each other, with the exception of 7 sequence types grouped into three clonal groups. Two (6.25%) out of 32 serotypeable isolates (1 serotype a and 1 serotype b) and 6 (30%) of 20 NST isolates were resistant to ampicillin due to beta-lactamase production. These results suggest a change in the epidemiology of H. influenzae disease, with the majority of invasive H. influenzae isolates being associated with serotype a and NST strains.
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Affiliation(s)
- Raymond S W Tsang
- Vaccine Preventable Bacterial Disease Section, National Microbiology Laboratory, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3R2.
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44
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Erwin AL, Allen S, Ho DK, Bonthuis PJ, Bonthius PJ, Jarisch J, Nelson KL, Tsao DL, Unrath WCT, Watson ME, Gibson BW, Apicella MA, Smith AL. Role of lgtC in resistance of nontypeable Haemophilus influenzae strain R2866 to human serum. Infect Immun 2006; 74:6226-35. [PMID: 16966407 PMCID: PMC1695526 DOI: 10.1128/iai.00722-06] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We are investigating a nontypeable Haemophilus influenzae (NTHI) strain, R2866, isolated from a child with meningitis. R2866 is unusually resistant to killing by normal human serum. The serum 50% inhibitory concentration (IC50) for this strain is 18%, approaching that of encapsulated H. influenzae. R3392 is a derivative of R2866 that was found to have increased sensitivity to human serum (IC50, 1.5%). Analysis of tetrameric repeat regions within lipooligosaccharide (LOS) biosynthetic genes in both strains indicated that the glycosyltransferase gene lgtC was out of frame ("off") in most colonies of R3392 but in frame with its start codon ("on") in most colonies of the parent. We sought antigenic and biochemical evidence for modification of the LOS structure. In a whole-cell enzyme-linked immunosorbent assay, strain R3392 displayed reduced binding of the Galalpha1,4Gal-specific monoclonal antibody 4C4. Mass spectrometry analysis of LOS from strain R2866 indicated that the primary oligosaccharide glycoform contained four heptose and four hexose residues, while that of R3392 contained four heptose and three hexose residues. We conclude that the R2866 lgtC gene encodes a galactosyltransferase involved in synthesis of the 4C4 epitope, as in other strains, and that expression of lgtC is associated with the high-level serum resistance that has been observed for this strain. This is the first description of the genetic basis of high-level serum resistance in NTHI, as well as the first description of LOS composition in an NTHI strain for which the complete genome sequence has been determined.
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Affiliation(s)
- Alice L Erwin
- Microbial Pathogens Program, Seattle Biomedical Research Institute, 307 Westlake Ave. North, Suite 500, Seattle, WA 98109-5219, USA
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45
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Sandqvist A, Kalies H, Siedler A, Gröndahl B, Schmitt HJ, Schweitzer-Krantz S, Messing-Jünger M, Pfeffer K, Mayatepek E, von Kries R, Schroten H. Invasive nontypeable Haemophilus influenzae infections in Germany: a case report of a previously healthy 7-year-old boy with an intracranial abscess, and epidemiological data from 2001 to 2004. Eur J Pediatr 2006; 165:658-9. [PMID: 16721541 DOI: 10.1007/s00431-006-0131-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Revised: 02/17/2006] [Accepted: 02/20/2006] [Indexed: 11/28/2022]
Affiliation(s)
- Anna Sandqvist
- Pediatric Infectious Diseases, Department of General Pediatrics, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Dusseldorf, Germany.
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46
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Agwu AG, Pasternak R, Joyner M, Carver CL, Francis HW, Siberry GK. Nontypeable Haemophilus influenzae meningitis complicated by hearing loss in a 9-year-old HIV-infected boy. AIDS Patient Care STDS 2006; 20:531-5. [PMID: 16893321 DOI: 10.1089/apc.2006.20.531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A 9-year old boy with perinatal HIV infection developed meningitis due to nontypeable Haemophilus influenzae. His course was complicated by progressive hearing loss due to labyrinthitis ossificans. Placement of cochlear implant improved hearing thresholds. Nontypeable H. influenzae meningitis and use of cochlear implants have not previously been in HIV-infected children.
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Affiliation(s)
- Allison George Agwu
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA
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47
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Erwin AL, Bonthuis PJ, Geelhood JL, Nelson KL, McCrea KW, Gilsdorf JR, Smith AL. Heterogeneity in tandem octanucleotides within Haemophilus influenzae lipopolysaccharide biosynthetic gene losA affects serum resistance. Infect Immun 2006; 74:3408-14. [PMID: 16714571 PMCID: PMC1479228 DOI: 10.1128/iai.01540-05] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Haemophilus influenzae is subject to phase variation mediated by changes in the length of simple sequence repeat regions within several genes, most of which encode either surface proteins or enzymes involved in the synthesis of lipopolysaccharides (LPS). The translational repeat regions that have been described thus far all consist of tandemly repeated tetranucleotides. We describe an octanucleotide repeat region within a putative LPS biosynthetic gene, losA. Approximately 20 percent of nontypeable H. influenzae strains contain copies of losA and losB in a genetic locus flanked by infA and ksgA. Of 30 strains containing losA at this site, 24 contained 2 tandem copies of the octanucleotide CGAGCATA, allowing full-length translation of losA (on), and 6 strains contained 3, 4, 6, or 10 tandem copies (losA off). For a serum-sensitive strain, R3063, with losA off (10 repeat units), selection for serum-resistant variants yielded a heterogeneous population in which colonies with increased serum resistance had losA on (2, 8, or 11 repeat units), and colonies with unchanged sensitivity to serum had 10 repeats. Inactivation of losA in strains R3063 and R2846 (strain 12) by insertion of the cat gene decreased the serum resistance of these strains compared to losA-on variants and altered the electrophoretic mobility of LPS. We conclude that expression of losA, a gene that contributes to LPS structure and affects serum resistance, is determined by octanucleotide repeat variation.
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Affiliation(s)
- Alice L Erwin
- Bacterial Pathogenesis Program, Seattle Biomedical Research Institute, 307 Westlake Ave. N., Suite 500, Seattle, WA 98109-5219, USA.
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48
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Chen SJ, Chu ML, Wang CJ, Liao CL, Hsieh SL, Sytwu HK, Wang CC. Kinetic Th1/Th2 responses of transgenic mice with bacterial meningitis induced by Haemophilus influenzae. Clin Sci (Lond) 2006; 111:253-63. [PMID: 16623660 DOI: 10.1042/cs20060060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To investigate the kinetic Th1/Th2 immunopathogenic mechanisms of Haemophilus influenzae meningitis, we established a murine experimental model of meningitis and elucidated the Th1/Th2 immune responses in T1/T2 doubly transgenic mice based on a BALB/c background under the control of the IFN-gamma (interferon-gamma)/IL-4 (interleukin-4) promoters respectively. NTHi (non-typeable Haemophilus influenzae) meningitis was induced in these mice by inoculation with either a colonized (CNTHi) or invasive (INTHi) strain of NTHi. Mice inoculated with CNTHi displayed a less severe degree of disease in terms of clinical symptoms, mortality rate and brain histopathology. Conversely, INTHi-inoculated mice had more severe clinical symptoms. CNTHi-inoculated mice had a more significant Th1 response in terms of a higher percentage and longer maintenance of Th1 cells, and more production of IFN-gamma from strain-specific antigen-stimulated splenocytes than INTHi-inoculated mice. In contrast, INTHi-inoculated mice had a more significant Th2 response. This was due to a significant increase in IL-4-producing CD4(+) T-cells (Th2 cells) and more production of IL-4 from strain-specific antigen-stimulated splenocytes accompanied by a rapid decline of Th1 cells in INTHi-inoculated mice. In conclusion, the preferential Th1/Th2 trend in this murine model of NTHi meningitis is correlated with clinical severity as well as isolated characteristics of the pathogens themselves.
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Affiliation(s)
- Shyi-Jou Chen
- The Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
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49
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Avadhanula V, Rodriguez CA, Devincenzo JP, Wang Y, Webby RJ, Ulett GC, Adderson EE. Respiratory viruses augment the adhesion of bacterial pathogens to respiratory epithelium in a viral species- and cell type-dependent manner. J Virol 2006; 80:1629-36. [PMID: 16439519 PMCID: PMC1367158 DOI: 10.1128/jvi.80.4.1629-1636.2006] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Secondary bacterial infections often complicate respiratory viral infections, but the mechanisms whereby viruses predispose to bacterial disease are not completely understood. We determined the effects of infection with respiratory syncytial virus (RSV), human parainfluenza virus 3 (HPIV-3), and influenza virus on the abilities of nontypeable Haemophilus influenzae and Streptococcus pneumoniae to adhere to respiratory epithelial cells and how these viruses alter the expression of known receptors for these bacteria. All viruses enhanced bacterial adhesion to primary and immortalized cell lines. RSV and HPIV-3 infection increased the expression of several known receptors for pathogenic bacteria by primary bronchial epithelial cells and A549 cells but not by primary small airway epithelial cells. Influenza virus infection did not alter receptor expression. Paramyxoviruses augmented bacterial adherence to primary bronchial epithelial cells and immortalized cell lines by up-regulating eukaryotic cell receptors for these pathogens, whereas this mechanism was less significant in primary small airway epithelial cells and in influenza virus infections. Respiratory viruses promote bacterial adhesion to respiratory epithelial cells, a process that may increase bacterial colonization and contribute to disease. These studies highlight the distinct responses of different cell types to viral infection and the need to consider this variation when interpreting studies of the interactions between respiratory cells and viral pathogens.
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Affiliation(s)
- Vasanthi Avadhanula
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Mailstop 320, 332 N. Lauderdale St., Memphis, TN 38105, USA
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Giufrè M, Muscillo M, Spigaglia P, Cardines R, Mastrantonio P, Cerquetti M. Conservation and diversity of HMW1 and HMW2 adhesin binding domains among invasive nontypeable Haemophilus influenzae isolates. Infect Immun 2006; 74:1161-70. [PMID: 16428765 PMCID: PMC1360295 DOI: 10.1128/iai.74.2.1161-1170.2006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The pathogenesis of nontypeable Haemophilus influenzae (NTHi) begins with adhesion to the rhinopharyngeal mucosa. In almost 80% of NTHi clinical isolates, the HMW proteins are the major adhesins. The prototype HMW1 and HMW2 proteins, identified in NTHi strain 12, exhibit different binding specificities. The two binding domains have been localized in regions of maximal sequence dissimilarity (40% identity, 58% similarity). Two areas within these binding domains have been found essential for full level adhesive activity (designated the core-binding domains). To investigate the conservation and diversity of the HMW1 and HMW2 core-binding domains among isolates, PCR and DNA sequencing were used. First, we separately amplified the hmw1A-like and hmw2A-like structural genes in nine invasive NTHi isolates, discovering two new hmwA alleles, whose sequences are herein reported. Then, the hmw1A-like and hmw2A-like PCR products were used as the template in nested PCR to produce amplicons encompassing the encoding sequences of the two core-binding domains. In-depth sequence analysis was then performed among sequences of each group, with the support of specific computer programs. Overall, extensive sequence diversity among isolates was highlighted. However, similarity plots showed patterns consisting of peaks of relatively high similarity alternating with strongly divergent regions. The phylogenetic tree clearly indicated the HMW1-like and HMW2-like core-binding domain sequences as two clusters. Distinct sets of conserved amino acid motifs were identified within each group of sequences using the MEME/MOTIFSEARCH tool. Since HMW adhesins could represent candidates for future vaccines, identification of specific patterns of conserved motifs in otherwise highly variable regions is of great interest.
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Affiliation(s)
- Maria Giufrè
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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