Antimicrobial susceptibilities and serotypes of Streptococcus pneumoniae in southwestern Japan and correlation of penicillin-binding protein 2b and 2x mutations in susceptibilities of penicillin G and cefotaxime

Bacterial infections in acute exacerbation of chronic obstructive pulmonary disease: a systematic review and meta-analysis

OBJECTIVE

Due to the importance of Chronic obstructive pulmonary disease (COPD) as the fourth cause of mortality worldwide and the lack of studies evaluating the prevalence of bacterial infections in disease exacerbation, this systematic review and meta-analysis was performed to determine the prevalence rate of bacterial infections in COPD patients.

METHODS

PubMed, ISI Web of Science, and Scopus databases were systematically searched for population-based prevalence studies (1980-2018). MeSH terms for "Bacterial infections" and "AECOPD" were used as search keywords. The selected studies were filtered according to the inclusion and exclusion criteria. Fixed and random-effects models were used for estimation of summary effect sizes. Between-study heterogeneity, as well as publication bias, were calculated.

RESULTS

Finally, 118 out of 31,440 studies were selected. The overall estimation of the prevalence of bacterial infection was 49.59% [95% confidence interval (CI) 0.4418-0.55]. The heterogeneity in estimating the pooled prevalence of bacterial infections was shown in the studies (Cochran Q test: 6615, P < 0.0001, I² = 98.23%). In addition, S. pneumoniae, H. influenzae, M. catarrhalis, A. baumannii, P. aeruginosa, and S. aureus were the most prevalent reported bacteria.

CONCLUSIONS

Our results as the first meta-analysis for the issue demonstrated that bacterial infections are an important risk factor for AECOPD. Further studies must be performed for understanding the exact role of bacterial agents in AECOPD and help physicians for more applicable preventive and therapeutic measurements.

Comparative in vitro activities of carbapenem antimicrobial agents against 264 penicillin-resistant Streptococcus pneumoniae isolates from Korea

We compared in vitro activities of carbapenems against 264 penicillin-resistant Streptococcus pneumoniae (PRSP) isolates. The MIC(50)/MIC(90) (microg/mL) values of imipenem, meropenem, ertapenem, and panipenem were 1/1, 0.25/0.25, 0.25/0.5, and 0.125/0.25, respectively. The susceptibility rates to imipenem, meropenem, and ertapenem were 0%, 85.2%, and 99.6%, respectively. Compared with imipenem and meropenem, ertapenem and panipenem had better in vitro activities against PRSP.

High prevalence of erythromycin resistance and macrolide-resistance genes, mefA and ermB, in Streptococcus pneumoniae isolates from the upper respiratory tracts of children in the Sapporo district, Japan

Our previous study demonstrated that the frequency of penicillin-resistant Streptococcus pneumoniae (PRSP) was lower in our district than in districts in other Japanese studies. In this study, we investigated the prevalence of erythromycin resistance. The susceptibility to erythromycin and the distribution of the macrolide-resistance genes, mefA and ermB, were examined in S. pneumoniae isolates from the upper respiratory tracts of children in four cities in the Sapporo district, Hokkaido prefecture, Japan. Of the 156 isolates, 27 (17.3%) were erythromycin-sensitive, 6 (3.9%) were erythromycin-intermediately resistant, and 123 (78.9%) were erythromycin-resistant. Fifty-nine (37.8%) had the mefA gene, 89 (57.1%) had the ermB gene, and 129 (82.7%) had the mefA and/or the ermB gene. The ermB-positive isolates tended to show high resistance to erythromycin. Erythromycin-resistant isolates and the macrolide-resistance genes were often present in infants or younger children. The frequency of erythromycin-resistant isolates in the four cities was very high, ranging from 76.3% to 83. 3%, as high as the national average. Although erythromycin-resistant isolates generally tend to show cross-resistance to penicillin, the frequency of PRSP was very low in this study, as compared with other Japanese studies. Erythromycin resistance was frequently recognized not only in PRSP but also in penicillin-sensitive S. pneumoniae (PSSP) as well. In Japan, erythromycin resistance may have already become widespread, even in local areas where penicillin resistance is not especially prevalent.

Alterations of pbp1a, pbp2b, and pbp2x in Streptococcus pneumoniae isolates from children with otolaryngological infectious disease in the Sapporo district of Japan

Evaluation of beta-lactam susceptibility and polymerase chain reaction (PCR)-based genotyping of penicillin-binding proteins (PBP) 1A, 2B, and 2X were performed for Streptococcus pneumoniae isolates from children with otolaryngological infectious disease in the Sapporo district, Hokkaido Prefecture, Japan. Of 174 S. pneumoniae isolates, 14 (8%) were penicillin-resistant S. pneumoniae (PRSP), 87 (50%) were penicillin-intermediately-resistant, and 73 (42%) were penicillin-sensitive. Seventy-six (44%) had alterations in all of the three genes examined (pbp1a, pbp2b, and pbp2x), 81 (47%) had alterations in one or two of the genes, and 17 (10%) had no alterations. Isolates with alterations in all three genes showed low susceptibility to penicillin, while, in contrast, isolates with no alteration showed relatively high susceptibility to penicillin. Similar relationships were observed for other beta-lactams. The prevalence of PRSP in our study ranged from 5% to 12.8% (average, 8%), and there was much variation in the prevalence of PBP gene alterations among the cities. The results suggest that local differences in patterns of PBP gene alterations can be observed even at the district level. PCR-based genotyping of PBP genes is rapid, convenient, and useful to investigate genetic susceptibility to beta-lactams. Further, not only nationwide or prefectural surveys but also local surveillance at the district level is important for determining antimicrobial susceptibility status in daily practice.

Determination of penicillin resistance in Streptococcus pneumoniae isolates from southern Brazil by PCR

OBJECTIVE

To demonstrate the potential clinical applicability of the PCR technique to the early detection of bacterial resistance in Streptococcus pneumoniae.

METHODS

We studied 153 samples of S. pneumoniae, isolated from different anatomic sites, using polymerase chain reaction (PCR) for the detection of specific amplicons from genes that code for penicillin-binding proteins (PBP) 1a, 2b and 2x, which are responsible for penicillin resistance in this organism. The occurrence of these mutated genes was correlated with the minimum inhibitory concentration (MIC) of penicillin, determined by the agar dilution test.

RESULTS

The rate of penicillin resistance in S. pneumoniae in Porto Alegre, Brazil was 22.8% (16.3% intermediate resistance and 6.5% high resistance). In a statistically significant proportion of cases (p < 0.05), penicillin-susceptible samples had no amplicons, intermediate samples had only one (generally from PBP 2x), and highly resistant samples had amplicons from all three PBPs investigated.

CONCLUSION

These results suggest that penicillin resistance in S. pneumoniae in southern Brazil is on the increase, but is still lower than in other countries, and that PCR could be used for its early detection.

A reação em cadeia da polimerase na detecção da resistência à penicilina em Streptococcus pneumoniae

INTRODUÇÃO: O Streptococcus pneumoniae é o mais freqüente agente etiológico de infecções respiratórias adquiridas na comunidade e sua resistência aos antimicrobianos tem aumentado nos últimos anos. A determinação da resistência é feita rotineiramente por método lento que depende do crescimento em cultura e determinação da concentração inibitória mínima (CIM). A reação em cadeia da polimerase (PCR) detecta os genes responsáveis pela resistência do Streptococcus pneumoniae a penicilina em cerca de 8 horas. OBJETIVO: Comparar a PCR com o método da CIM no diagnóstico da resistência da Streptococcus pneumoniae a penicilina. MÉTODO: Foram estudadas 153 amostras de Streptococcus pneumoniae, isoladas de diferentes sítios anatômicos, usando-se para detecção de mutações nos genes que codificam as proteínas ligadoras de penicilina 1a, 2b e 2x, responsáveis pela resistência à penicilina. A ocorrência das mutações foi correlacionada com a CIM de penicilina, determinada pelo teste de difusão em ágar. RESULTADOS: A resistência global à penicilina do Streptococcus pneumoniae foi de 22,8% (16,3% de resistência intermediária e 6,5% de resistência alta). Em proporções estatisticamente significativas, as amostras sensíveis à penicilina não tinham mutações, as intermediárias apenas uma, geralmente na proteína ligadora de penicilina 2x, e as altamente resistentes tinham mutações nas três proteínas investigadas. CONCLUSÃO: A PCR é um método rápido para a detecção da resistência à penicilina do Streptococcus pneumoniae, que poderá vir a ser utilizado na prática clínica.

Panipenem/betamipron

Panipenem is a parenteral carbapenem antibacterial agent with a broad spectrum of in vitro activity covering a wide range of Gram-negative and Gram-positive aerobic and anaerobic bacteria, including Streptococcus pneumoniae and species producing beta-lactamases. Panipenem is coadministered with betamipron to inhibit panipenem uptake into the renal tubule and prevent nephrotoxicity. In large, randomised clinical trials, panipenem/betamipron demonstrated good clinical and bacteriological efficacy (similar to that of imipenem/cilastatin) in adults with respiratory tract or urinary tract infections. Panipenem/betamipron was also effective in adults with surgical or gynaecological infections, and in paediatric patients with respiratory tract and urinary tract infections in noncomparative trials. In small trials in elderly patients reported as abstracts, panipenem/betamipron demonstrated clinical efficacy similar to intravenous piperacillin and greater than oral ofloxacin in urinary tract infections. Elderly patients with respiratory tract infections also responded to therapy. Panipenem/betamipron is well tolerated with few adverse events reported in clinical trials, most commonly elevated serum levels of hepatic transaminases and eosinophils, rash and diarrhoea.

A case of retropharyngeal abscess caused by penicillin-resistant Streptococcus pneumoniae

We report here a case of a 1-year-old girl with retropharyngeal abscess caused by penicillin-resistant Streptococcus pneumoniae (PRSP). Computed tomography disclosed a retropharyngeal mass lesion (4 cm x 3 cm in diameter), and the diagnosis was confirmed by needle aspiration of the retropharyngeal space, which yielded PRSP. To our knowledge, this is the first report of a young subject in whom retropharyngeal abscess was caused by this organism. Retropharyngeal abscess is most common in children younger than 3 or 4 years of age, during which period a high carriage rate of PRSP is also shown. This patient was successfully treated with panipenem/betamipron.

Antimicrobial resistance trends in community-acquired respiratory tract pathogens in the Western Pacific Region and South Africa: report from the SENTRY antimicrobial surveillance program, (1998-1999) including an in vitro evaluation of BMS284756

From 1998 to 1999, a large number of community-acquired respiratory tract isolates of Streptococcus pneumoniae (n=566), Haemophilus influenzae (n=513) and Moraxella catarrhalis (n=228) were collected from 15 centres in Australia, Hong Kong, Japan, China, the Philippines, Singapore, South Africa and Taiwan through the SENTRY Antimicrobial Surveillance Program. Isolates were tested against 26 antimicrobial agents using the NCCLS-recommended methods. Overall, 40% of S. pneumoniae isolates were resistant to penicillin with 18% of strains having high-level resistance (MIC > or =2 mg/l). Rates of erythromycin and clindamycin resistance were 41 and 23%, respectively. Penicillin-resistant strains showed high rates of resistance to other antimicrobial agents: 96% to trimethoprim-sulphamethoxazole (TMP-SMX), 84% to tetracycline and 81% to erythromycin. A significant proportion of penicillin-susceptible strains was also resistant to erythromycin (21%), tetracycline (29%) and TMP-SMZ (26%). Small numbers of strains were resistant to levofloxacin (0.7%), trovafloxacin (0.4%) and grepafloxacin (1.3%) where as all strains remained uniformly susceptible to quinupristin/dalfopristin and BMS284756 (MIC(90), 0.06 mg/l), a new desfluoroquinolone. beta-lactamases were, produced by 20% H. influenzae isolates and only rare strains showed intrinsic resistance to amoxycillin. Other beta-lactam agents showed good activity with rates of resistance less than 2% and all isolates showed susceptibility to cefixime, ceftibuten, cefepime and cefotaxime. Rates of resistance to tetracycline and chloramphenicol were also relatively low at 3%. The majority (98%) of M. catarrhalis isolates was found to be beta-lactamase-positive and resistant to penicillins, however, resistance to erythromycin and tetracycline was also low at 1.8%. Both H. influenzae and M. catarrhalis isolates were uniformly susceptible to the new desfluoroquinolone and tested fluoroquinolones.

Review of cefditoren, an advanced-generation, broad-spectrum oral cephalosporin

BACKGROUND

Cefditoren is an advanced-generation, broad-spectrum cephalosporin antibiotic approved for the treatment of acute bacterial exacerbation of chronic bronchitis (AECB), group A beta-hemolytic streptococcal pharyngotonsillitis, and uncomplicated skin/skin structure infections in adult and adolescent patients.

OBJECTIVE

This article briefly reviews the chemistry, antimicrobial activity, pharmacokinetics, efficacy, and safety of cefditoren.

METHODS

Literature was identified by a MEDLINE search (January 1985 to October 2001) of the medical literature, review of the English-language literature, reference lists within these articles, as well as data presented at the 40th Interscience Conference on Antimicrobial Agents and Chemotherapy.

RESULTS

Cefditoren has a broad spectrum of activity against many gram-negative and gram-positive aerobes, including Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis. Cefditoren is stable to hydrolysis by many common beta-lactamases. Cefditoren is rapidly absorbed (time to peak plasma concentration, approximately 2-3 hours) from the gastrointestinal tract and is almost completely eliminated via renal clearance of unchanged drug. The terminal disposition half-life of the compound is approximately 0.8 to 1.3 hours.

CONCLUSIONS

Cefditoren is effective in the management of AECB (in regimens of 400 mg twice daily for 10 days) and acute maxillary sinusitis, pharyngotonsillitis due to S pyogenes, and uncomplicated skin/skin structure infections (in regimens of 200 mg twice daily for 10 days). Cefditoren possesses broad activity against common pathogens of the respiratory tract and skin and is stable in the presence of numerous beta-lactamases. Its pharmacokinetic properties, in conjunction with in vitro susceptibility data, document the feasibility of twice-daily dosing.

Increasing threat of Gram-positive bacterial infections in the intensive care unit setting

The effects of resistance are being noted on an increasing scale in the intensive care unit (ICU). Around the world, new epidemiologic patterns of ICU occurrence are being observed for Gram-positive multidrug-resistant organisms. Current problems include the appearance of insusceptibility to vancomycin and other glycopeptides in Staphylococcus aureus organisms that are virulent enough to cause infection in patients with normal host defenses. In addition, multidrug-resistant organisms like methicillin-resistant S.aureus are spreading from healthcare to community settings, and community organisms like Streptococcus pneumoniae are spreading to healthcare settings. Focal persistence and subsequent worldwide spread of enterococci resistant to vancomycin and other glycopeptides and multiple-resistance mechanisms in the same organism also require attention. Strategies such as multidisciplinary management of infections, appropriate infection control measures, and surveillance of resistance patterns are necessary to address the problem of resistance. Intensivists have been prominent in research and control efforts in this field and should continue to lead future efforts.