[Clinical Characteristics of Invasive Pneumococcal Disease of the Mucoid Phenotype: A Case Series]

Streptococcus pneumoniae is a gram-positive coccus that causes invasive and non-invasive pneumococcal diseases. Invasive pneumococcal disease (IPD) is defined as an infection confirmed by the isolation of S. pneumoniae from a normally sterile site. IPD has a high mortality rate of around 20% in adults. Colonies of S. pneumoniae show various morphological features which include a mucoid appearance. The production of large amounts of capsular polysaccharide gives colonies of S. pneumoniae their mucoid appearance. This is thought to be a mechanism of microbial escape from phagocyte killing, leading to strong pathogenicity despite their high susceptibility to antibiotics. To our knowledge, the clinical characteristics of patients with mucoid IPD are unknown. We retrospectively analyzed the records of adult patients with IPD of the mucoid phenotype at Teine Keijinkai Hospital, Hokkaido, Japan, between 2009 and 2015. Seven patients (six males) with age range between 62 and 80 years were diagnosed as having mucoid IPD during the study period. Two patients had a history of malignancy and diabetes mellitus respectively, and six patients were living independently. No patients were previously vaccinated with pneumococcal vaccine. Six patients had clinical manifestations of pneumonia; one patient had multiple concomitant complications of mastoiditis, meningitis, and prosthetic joint infection. All isolates were isolated from blood. All isolates were susceptible to beta-lactam antibiotics, while six isolates were resistant to macrolides and chloramphenicol. Based on the Quellung reaction and real-time polymerase chain reaction (PCR) results, one isolate of mucoid phenotype was confirmed as serotype 3 with the penicillin binding protein gene of pbp2x and the macrolide resistant gene of ermB. Although all patients received appropriate antibiotics based on susceptibility testing, four patients required mechanical ventilation and vasopressors. One patient had neurological sequelae (hypacusis) and two patients died during the course of hospitalization. This case series suggests that mucoid IPD can occur in immunocompetent hosts and can cause high mortality. Since most of the mucoid phenotype of S. pneumoniae are serotype 3, widespread use of pneumococcal vaccine is important to prevent morbidity and mortality associated with IPD.

Vaccination of chemotherapy patients--effect of guideline implementation

PURPOSE

Despite substantial morbidity and mortality of influenza and pneumococcal infections in cancer patients treated with chemotherapy, vaccination against both illnesses is infrequent. We evaluated the impact of implementation of clinical guidelines on vaccination of chemotherapy patients treated in our institute.

METHODS

We performed a prospective audit before (2012) and after (2013-2014) the introduction of immunisation guidelines for chemotherapy patients in a UK tertiary cancer centre.

RESULTS

Guideline implementation was associated with a significant increase in the rate of pneumococcal vaccination compared to the 2012 baseline (47 vs. 25 %, P = 0.0018), though this was not sustained the following year (34 %, P = 0.13, vs. baseline). Influenza vaccine coverage was high (∼ 70 %) throughout. There was a marked disparity between patients aged ≤ 65 and those >65 years in the rate of pneumococcal vaccination in both 2013 and 2014 (38 vs. 68 % and 17 vs. 53 %, respectively, both P < 0.001), and, to a lesser extent, in the rate of influenza vaccination in the same period (64 vs. 82 %, P < 0.1, and 63 vs. 85 %, P = 0.009, respectively).

CONCLUSIONS

The implementation of clinical vaccine guidelines was associated with a significant increase in pneumococcal vaccination, though continued effort appears required to deliver persistent improvement. Initiatives to increase vaccination uptake in patients aged ≤ 65 are merited.

[Epidemiology of acute otitis media caused by Streptococcus pneumoniae: emergence of serotype 19A]

In this study, the authors report the distribution of serogroups/serotypes and their susceptibility profiles of Streptococcus pneumoniae causing recurrent and difficulties to treat acute otitis media (AOM) in children obtained at the ENT outpatient clinic of Robert Debré Hospital in Paris, between 2002-2008 after the implementation of the 7-valent pneumococcal conjugate vaccine. In this retrospective study, 126 S. pneumoniae isolates were obtained by tympanocentesis from 126 children with AOM during three different periods: 2002-2003 (period 1), 2004-2005 (period 2), and 2006-2008 (period 3). In period 1, the most common serotype was 19F. Between period 1 and period 3, the proportion of serotype 19F decreased from 39 to 13% (P=0.03). In contrast, the proportion of serotype 19A increased from 25 to 60% (P=0.03). So, they observed that vaccine-related serotype 19A became dominant among young children with AOM in 2006-2008. Overall, 15.1% of the isolates were penicillin susceptible, 73.8% intermediate and 11.1% were resistant. Most (94%) of the S. pneumoniae serotype 19A were penicillin intermediate.

[Case of diabetes mellitus associated with cervical pyogenic spondylitis and meningoencephalitis secondary to retropharyngeal abscess caused by Streptococcus pneumoniae]

A 63-year-old man with diabetes mellitus had undergone insulin therapy for 10 years. He developed symptoms of upper respiratory tract infection and neck pain. After 5 days, he suddenly experienced high fever and consciousness disturbance. Neurological examination detected drowsiness and neck stiffness. Cerebrospinal fluid (CSF) examination revealed pleocytosis with low glucose level. Gram staining and a latex agglutination test of his CSF revealed Streptococcus pneumoniae to be the causative organism of meningoencephalitis in the patient. Gadolinium-enhanced T1-weighted images obtained from a cervical spine MRI showed ring enhancement in the anterior clivus and thickening in the anterior dura matter with specific thickening at the dens of the axis. Based on the diagnosis of cervical pyogenic spondylitis and meningoencephalitis secondary to retropharyngeal abscess caused by Streptococcus pneumoniae, the patient was administered panipenem/betamipron and dexamethasone, following which his neurological symptoms and signs gradually improved. Diabetes mellitus is a factor that predisposes patients to invasive pneumococcal infection. Thus, we conclude that physicians need to be aware of the possible development of cervical pyogenic spondylitis and meningoencephalitis subsequent to Streptococcus pneumoniae infection, and symptoms such as fever and neck pain should be carefully examined.

[Preliminary investigation into the allergic rhinitis complicated with acute bacterial sinusitis in mice]

OBJECTIVE

To develop a mouse model of bacterial rhinosinusitis superposed on allergic rhinitis (AR), and to explore whether ongoing allergic rhinitis enhance the acute sinus infection and inflammation associated with Streptococcus pneumoniae (SP).

METHODS

Fourty mice of C57BL6/J were randomly divided on average into 4 groups: A [ovalbumin (OVA) + SP], B [OVA + normal saline (NS)], C [phosphate buffered solution (PBS) + SP] and D (PBS + NS). (1) Group A and B were sensitized by intraperitoneal injection with 200 microl (10%) OVA on days 1 through 9, and exposed to OVA (6%) intranasally on days 10 through 17, to induce allergic inflammation. OVA was replaced with PBS in group C and D in the same way. (2) Subsequently, group A and C were inoculated with SP intranasally on day 13, and NS was used in group B and D. On the 6th day after inoculation, mice were killed. Blood was collected from the orbital venous sinus after anesthesia. The heads were embedded with paraffin and serial sections were followed and stained with hematoxylin-eosin and toluidine blue (0.5%) for histological analysis and inflammation cells count. The number of polymorphonuclear neutrophils (PMN) and eosinophils (EOS) per square millimeter of sinus mucosa were calculated by using a computer-aided special software under microscope.

RESULTS

AR models were successfully established in 9 mice from group A and 8 from group B. Histologic examination of the sinus from group A and B revealed significant mucosal edema and dilated venules. The symptoms were mild in group C, and no symptom was observed in group D. PMN (x +/- s) in group A (139.3 +/- 26.5)/mm2 was significantly higher than that in group B (70.7 +/- 16.7)/mm2, C (63.0 +/- 14.7)/mm2 and D (40.2 +/- 14.1)/mm2 respectively (P < 0.01); EOS and serous IL-5 level in group A (134.6 +/- 25.5)/mm2, (48.2 +/- 13.9) pg/ml and B (116.2 +/- 25.2)/mm2, (40.8 +/- 7.8) pg/ml, were higher than that in group C (16.7 +/- 2.7)/mm2, (23.9 +/- 8.7) pg/ml (P < 0.05) and D (13.4 +/- 4.9)/mm2, (24.6 +/- 6.5) pg/ml (P < 0.05).

CONCLUSIONS

The data demonstrate that an ongoing local allergic response augments bacterial infection in mice, and allergic sensitization alone without SP does not induce the sinus infection.

[Survey of nasopharyngeal carriage of Haemophilus influenzae and Streptococcus pneumoniae in infants at day care centers]

Infants at day care centers tend to contract repetitive upper respiratory infections and prolonged otitis media. The increase in antimicrobial-resistant bacteria, particularly in infants, has given rise to a stubborn therapeutic problem. We studied the nasopharyngeal carriage and drug resistance to Haemophilus influenzae (H. influenzae) and Streptococcus pneumoniae (S. pneumoniae), the most common pathogens of upper respiratory infections, in infants at day care centers. Nasopharyngeal cultures of infants between the ages of 0 and 6 years were conducted at two day care centers in July 2004 ("summer"; n=183), and in February 2005 ("winter"; n=182). Isolated H. influenzae and S. pneumoniae were subjected to antibiotic susceptibility tests by broth microdilution. We also conducted an otolaryngological examination and a survey on past and life histories. H. influenzae in summer (38.3%) increased significantly in winter (57.7%). Beta-lactamase-negative and positive ampicillin-resistant H. influenzae (BLNAR+ BLPAR) in summer decreased significantly in winter. S. pneumoniae did not differ in summer (42.1%) or in winter (43.4%). Penicillin-resistant and intermediate S. pneumoniae (PRSP+PISP) was 41.3% in summer and decreased significantly to 19.0% in winter. BLNAR + BLPAR and PRSP + PISP differed with the day care center. In otolaryngological examination, rhinosinusitis was commonest (28.4% in summer and 30.8% in winter), followed by allergic rhinitis (8.7% in summer and 6.0% in winter) and otitis media (8.2% in summer and 6.0% in winter). Tonsillitis was minor (0.5% in both seasons). Rhinosinusitis in winter was significantly higher in carriers of H. influenzae and/or S. pneumoniae than in non carriers (36.4% versus 16.0%). Breast-fed infants tended to have less otitis media than bottle-fed infants (38.2% versus 52.9%). H. influenzae and/or S. pneumoniae plateaued (75-80%) after 12 months in day care centers. These results suggest that infants attending day care centers are immediately colonized by H. influenzae and S. pneumoniae in the nasopharynx after entering the centers. Nasopharyngeal drug-resistant H. influenzae and S. pneumoniae varied during the seasons and between day care centers. Further prospective studies are needed to determine upper respiratory tract infection in infants at day care centers and to evaluate carriage, epidemiology, and the drug-resistance rates of these pathogens.

Cavitatory lung disease complicating empyema in children

OBJECTIVE

The incidence of empyema has increased dramatically in children in the UK over the last decade. Streptococcus pneumoniae (S. pneumoniae) serotype 1 is the dominant serotype. We have observed more pneumatocoele and bronchopleural fistulae formation over this time.

AIM

Our aim was to determine the number of children who developed cavitatory disease as a complication of empyema at a tertiary referral centre and whether there was any association with S. pneumoniae serotype 1.

METHOD

We reviewed 75 cases presenting with empyema or parapneumonic effusion between February 1997 and July 2003. Bacterial culture and pneumococcal antigen detection were supplemented by real-time polymerase chain reaction (PCR) to detect pneumococcal DNA.

RESULTS

Cavitatory disease was present in 15 cases. Three children developed bronchopleural fistulae. S. pneumoniae was detected in 13 of 15 cases (4 cases serotype 1, 3 serotype 3, 2 serotype 14, and 2 serotype 9V; serotype assay was not performed in two cases). Staphylococcus aureus (S. aureus) was isolated in one case. No organism was isolated in the final case but an Antistreptolysin-O titre was >800 U/ml on two occasions suggestive of group A streptococcal infection.

CONCLUSION

Twenty percentage of cases of empyema in our series were complicated by cavitatory lung disease. It is an important complication of childhood empyema associated classically with S. aureus, but these data suggest that S. pneumoniae now appears to be the main cause. There does not seem to be an association with any particular serotype.

[A case of sphenoid sinusitis which could be diagnosed by orbital computed tomography after detected Strepotococcus pneumoniae from blood culture]

We report a case of sphenoid sinusitis which could be diagnosed by orbital CT after detecting Strepotococcus pneumoniae from blood culture. A previously healthy 47 year-old Japanese male was admitted to our hospital with severe left-sided headache of 2 days duration. From 9 days before hospitalization (1st day), the patient complained of cough and sputum. On physical examination, his neck was supple and his temperature was 38.3 degrees C. The rest of the examination was normal. A chest radiograph, sinus radiograph, and head computed tomographic (CT) scan without contrast material disclosed no abnormalities. Lumbar puncture was done and cerebrospinal fluid was clear and cell counts and the levels of glucose and protein were normal. The peripheral white blood cell count was 14,400/fl, and the C-reactive protein level was 9.6 mg/dl. After blood, urine, pharyngeal mucus and cerebrospinal fluid cultures were obtained, empirical antibiotic therapy with 2 gms of piperacillin twice daily was begun. He complained sever left-sided retro-orbital headahe on the next day too. The lumbar puncture and head CT scan with contrast material was done again but gave no diagnostic clues. The examinations by the otolaryngologist, ophthalmologist and dentist found no abnormal findings. On the 3rd hospitalized day, Strepotococcus pneumoniae was detected from the blood culture taken on the 1st hospitalized day. A CT scan focused on orbita was done and revealed a low density area of the left sphenoid sinus. The dose of piperacillin was increased to 4 gms twice daily and continued for 24 days. The patient's headache improved and piperacillin was changed to oral levofloxacin 100 mg, three times daily on the 26th day. The medication was stopped on the 73th day. Isolated sphenoid sinusitis is rare, but crtitical complications such as cranial nerve involvement, brain abscess, and bacterial meningitis may happen. It is necessary to also think of sphenoid sinusitis in practices of patients with severe headache.

Effect of influenza virus on cilia and epithelial cells in the bronchi of mice

In order to determine the effect of infection with influenza virus on bronchial cilia of the mouse, ciliary beat has been visualized directly by microscopic examination of the bronchi in slices of fresh lung. Cilia have been shown also in sections of fixed tissue by the use of special silver staining methods. The results have shown persistence of the cilia in spite of severe viral infection and indicate that the lowered resistance to secondary pneumococcal infection which occurs in influenzal pneumonia of the mouse is not due to interference with the ciliary mechanism. By a process of exclusion, the findings give further support to the theory that lowered resistance to pneumococcal infection in influenzal pneumonia is due to edema fluid in the viral lesion furnishing a culture medium for inhaled pneumococci. A widely used method for evaluation of ciliary activity on respiratory epithelia has been the microscopic observation of wave-like movements in reflected light. This activity was observed readily in the bronchi of mice but evidence was obtained showing that at this site it was due to something other than ciliary beat. Further histopathologic observations were made in order to define the lesion of the bronchial epithelium that would permit sparing of ciliated cells. In addition to usual techniques, mice were injected with colchicine for estimation of the rate of cellular proliferation and were exposed to a large dose of roentgen rays to eliminate polymorphonuclear leucocytes. Stains for mucous and for mitochondria were done also. The evidence obtained favors the theory that the viral infection does not destroy any of the cells of the bronchial epithelium. Inclusion bodies were found in the cytoplasm, making it seem likely instead that viral particles grow in colony-like aggregations and that liberation of virus into the lumen takes place not only by simple extrusion of inclusions but also by detachment of inclusion-laden globular portions of the cytoplasm.

Hearing loss with stapedotomy in otitis media

OBJECTIVE

Stapes fixation is often found in patients with either active or inactive otitis media (OM). Stapedotomy is generally not performed in ears with OM because of the potential risk of sensorineural hearing loss (SNHL). Recent studies have demonstrated that the inner ear may be fenestrated in the presence of OM without significantly increased risk of SNHL. The goal of this study was to determine if stapedotomy in the presence of OM significantly increases the incidence of postoperative SNHL.

METHODS

Streptococcus pneumoniae or Pseudomonas aeruginosa was injected bilaterally into the middle ears of guinea pigs (n = 18 and 16, respectively). A control group (n = 14) was injected with saline solution. Two days postinjection, a unilateral stapedotomy was performed. Auditory thresholds were evaluated by electrocochleography before and after stapedotomy.

RESULTS

Bacterial OM was induced in all ears injected with pneumococci and pseudomonas. Auditory thresholds increased in all ears treated with stapedotomy. Stapedotomy performed in the presence of pseudomonas OM resulted in significantly greater SNHL than in control or pneumococcal ears (P = 0.0055). Hearing thresholds were not significantly different between pneumococcal OM and control ears treated with stapedotomy.

CONCLUSION

Stapedotomy in the presence of pseudomonas OM, but not pneumococcal OM, significantly increases the risk of SNHL in the guinea pig model.

SIGNIFICANCE

Stapedotomy should be avoided in patients with active OM, particularly in the presence of pseudomonas.

The three extra-cellular zinc metalloproteinases of Streptococcus pneumoniae have a different impact on virulence in mice

BACKGROUND

Streptococcus pneumoniae possesses large zinc metalloproteinases on its surface. To analyse the importance in virulence of three of these metalloproteinases, intranasal challenge of MF1 outbred mice was carried out using a range of infecting doses of wild type and knock-out pneumococcal mutant strains, in order to compare mice survival.

RESULTS

Observation of survival percentages over time and detection of LD50s of knock out mutants in the proteinase genes in comparison to the type 4 TIGR4 wild type strain revealed two major aspects: i) Iga and ZmpB, present in all strains of S. pneumoniae, strongly contribute to virulence in mice; (ii) ZmpC, only present in about 25% of pneumococcal strains, has a lower influence on virulence in mice.

CONCLUSIONS

These data suggest Iga, ZmpB and ZmpC as candidate surface proteins responsible for pneumococcal infection and potentially involved in distinct stages of pneumococcal disease.

Caspase-3 mediates hippocampal apoptosis in pneumococcal meningitis

Bacterial meningitis causes neuronal apoptosis in the hippocampal dentate gyrus, which is associated with learning and memory impairments after cured disease. The execution of the apoptotic program involves pathways that converge on activation of caspase-3, which is required for morphological changes associated with apoptosis. Here, the time course and the role of caspase-3 in neuronal apoptosis was assessed in an infant rat model of pneumococcal meningitis. During clinically asymptotic meningitis (0-12 h after infection), only minor apoptotic damage to the dentate gyrus was observed, while the acute phase (18-24 h) was characterized by a massive increase of apoptotic cells, which peaked at 36 h. In the subacute phase of the disease (36-72 h), the number of apoptotic cells decreased to control levels. Enzymatic caspase-3 activity was significantly increased in hippocampal tissue of infected animals compared to controls at 22 h. The activated enzyme was localized to immature cells of the dentate gyrus, and in vivo activity was evidenced by cleavage of the amyloid-beta precursor protein. Intracisternal administration of the caspase-3-specific inhibitor Ac-DEVD-CHO significantly reduced apoptosis in the hippocampal dentate gyrus. In contrast to a study where the decrease of hippocampal apoptosis after administration of a pan-caspase inhibitor was due to downmodulation of the inflammatory response, our data demonstrate that specific inhibition of caspase-3 did not affect inflammation assessed by TNF-alpha and IL-1beta concentrations in the cerebrospinal fluid space. Taken together, the present results identify caspase-3 as a key effector of neuronal apoptosis in pneumococcal meningitis.