The return of Pfeiffer’s bacillus: Rising incidence of ampicillin resistance in Haemophilus influenzae

Abstract

Haemophilus influenzae, originally named Pfeiffer’s bacillus after its discoverer Richard Pfeiffer in 1892, was a major risk for global health at the beginning of the 20th century, causing childhood pneumonia and invasive disease as well as otitis media and other upper respiratory tract infections. The implementation of the Hib vaccine, targeting the major capsule type of H. influenzae, almost eradicated the disease in countries that adapted the vaccination scheme. However, a rising number of infections are caused by non-typeable H. influenzae (NTHi), which has no capsule and against which the vaccine therefore provides no protection, as well as other serotypes equally not recognised by the vaccine. The first line of treatment is ampicillin, but there is a steady rise in ampicillin resistance. This is both through acquired as well as intrinsic mechanisms, and is cause for serious concern and the need for more surveillance. There are also increasing reports of new modifications of the intrinsic ampicillin-resistance mechanism leading to resistance against cephalosporins and carbapenems, the last line of well-tolerated drugs, and ampicillin-resistant H. influenzae was included in the recently released priority list of antibiotic-resistant bacteria by the WHO. This review provides an overview of ampicillin resistance prevalence and mechanisms in the context of our current knowledge about population dynamics of H. influenzae.

The Nontypeable Haemophilus influenzae Major Adhesin Hia Is a Dual-Function Lectin That Binds to Human-Specific Respiratory Tract Sialic Acid Glycan Receptors

“…According to WHO estimates, approximately 65 million people have moderate to severe COPD. Over 3 million people died of COPD in 2005, which corresponded to 5% of all deaths globally ( 7 ). Invasive disease caused by NTHi has increased significantly in recent years, in part as a result of broad usage of vaccines against Haemophilus influenzae type b and Streptococcus pneumoniae ( 8 ).…”

The Burden of Invasive Vaccine-Preventable Diseases in Adults in the Middle East and North Africa (MENA) Region

“…Studies have also shown that the prevalence of Hib carriage in children has decreased to \ 1% in the vaccine era [28]. Furthermore, substantial shifts in the epidemiology of invasive HI disease have been observed, with nontypeable HI (NTHi) becoming the main pathogenic lineage in post-Hib vaccination settings [29][30][31]. In contrast to Hib, which in the prevaccine era caused invasive disease mostly in healthy children aged \ 5 years, invasive NTHi infections occur mainly in neonates and the elderly and commonly in the presence of predisposing medical conditions [32].…”

Current microbiological aspects of community respiratory infection beyond COVID-19

“…Se ha comprobado sobre todo en los pacientes con fibrosis quística o con EPOC con colonización con P. aeruginosa [ 47 ]. Otras situaciones en las que es fácil objetivar el problema de la selección de mutantes resistentes es la que se presenta en los aislados de H. influenzae con mutaciones en la PBP3 (gen fstl ) [ 36 , 58 ]. Estos aislados pierden sensibilidad a las cefaloporinas orales como cefuroxima y cefixima y cuando los aislados además producen betalactamasas (aislados BLPACR) pierden también sensibilidad amoxicilina-ácido clavulánico y en mucha menor medida las cefalosporinas de uso intravenoso, cefotaxima y ceftriaxona, y la oral cefditoreno [ 36 , 38 ].…”