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At least 19 recordsLinked to original sources
PubMed1978

Efficacy of direct Gram stain in differentiating staphylococci from streptococci in blood cultures positive for gram-positive cocci.

A preponderance of clusters seen on direct Gram stain of blood cultures positive for gram-positive cocci was 98% sensitive and 100% specific for identification of staphylococcal species or of Peptococcus. A preponderance of chains, pairs, or both was 100% sensitive and 98% specific for identifying streptococci. Further presumptive identification of either staphylococci or streptococci based on microscopic morphology was unreliable. The direct Gram stain is highly reliable for differentiating staphylococci from streptococci and should be of considerable value to clinicians selecting initial antimicrobial therapy.

Blood↗
PubMed1976

In vitro activity of josamycin against aerobic gram-positive cocci and anaerobes.

Josamycin, a new macrolide antibiotic, was compared with ampicillin, erythromycin, and clindamycin in vitro against 25 isolates each of pneumococci, enterococci, Staphylococcus aureus, S. epidermidis, and nonenterococcal hemolytic streptococci and against 25 anaerobes including 10 Bacteroides fragilis. Minimal inhibitory concentration and minimal bactericidal concentration data were obtained for the aerobic organisms, using serial twofold tube dilutions in Mueller-Hinton broth. Minimal inhibitory concentrations were determined for the anaerobes by the agar dilution technique. Josamycin was comparable to erythromycin and clindamycin in activity against the pneumococci, streptococci, and staphylococci and was more active than clindamycin against enterococci. It was somewhat less active than ampicillin against enterococci and S. epidermidis and showed its greatest in vitro activity against anaerobes, being comparable to clindamycin.

Ampicillin↗
PubMed2025

In vitro activity of contezolid and other comparators against clinical Staphylococcus and Enterococcus: a multicenter study in China.

OBJECTIVE: To evaluate the in vitro activity of contezolid against clinical Staphylococcus and Enterococcus isolates from across China, and compare its performance with linezolid and other key agents. METHODS: A total of 2510 non-duplicate Gram-positive cocci isolates were collected from 70 hospitals in seven Chinese regions. Minimum inhibitory concentrations (MICs) were determined using broth microdilution (BMD) per CLSI guidelines. MIC50/90 values, susceptibility rates, cumulative MIC curves and MIC distribution agreement between contezolid and linezolid were assessed. Linezolid-resistant isolates and contezolid-resistant isolates-defined as those based on CLSI 2025 linezolid breakpoints-underwent whole-genome sequencing and comprehensive screening for known oxazolidinone resistance determinants, including acquired resistance genes, 23S rRNA mutations and amino acid substitutions in ribosomal proteins L3, L4 and L22. RESULTS: Contezolid exhibited potent in vitro activity, with >99% of isolates inhibited at ≤4 mg/L and showed lower MIC50/90 than linezolid, with a consistently left-shifted cumulative MIC distribution. Cohen's kappa analysis supporting enhanced activity of contezolid. Notably, we report for the first time clinical isolates with contezolid MICs up to 16 mg/L. Whole-genome analysis of 14 linezolid-resistant isolates (including five resistant to contezolid) revealed universal presence of optrA, cfr, fexA and other resistance genes, alongside domain V 23S rRNA mutations and substitutions in ribosomal proteins L3 and L4, supporting a shared genetic basis and potential cross-resistance between the two agents. CONCLUSIONS: Contezolid demonstrated potent and consistent activity against drug-resistant Gram-positive cocci, supporting its potential as a therapeutic alternative to linezolid. Further studies are needed to confirm resistance mechanisms and clinical utility.

Microbial Sensitivity Tests↗
PubMed1977

Azlocillin: in vitro studies of a new semisynthetic penicillin.

The activity of azlocillin, a new semisynthetic penicillin, was determined against 582 clinical isolates of gram-negative bacilli and gram-positive cocci. Over 75% of the isolates of Pseudomonas aeruginosa were inhibited at a concentration of 12.5 mug or less per ml. Azlocillin is also active against indole-negative and -positive Proteus spp., inhibiting 98 and 71%, respectively, at a concentration of 12.5 mug or less per ml. Isolates of Klebsiella spp. and Enterobacter spp. showed less susceptibility than isolates of Escherichia coli and Serratia spp. Gram-positive cocci except penicillin G-resistant Staphylococcus aureus were susceptible to azlocillin. Azlocillin failed to inhibit the growth of gram-negative bacilli when large inocula were used. It was more active in alkaline pH, but the type of medium used had little effect on its activity. Azlocillin was more active than mezlocillin, ticarcillin, and carbenicillin and as active as BLP-1654 against isolates of P. aeruginosa. It was not as active as mezlocillin against the majority of the other gram-negative bacilli.

Bacteria↗
PubMed1979

Anaerobic isolates in chronic recurrent suppurative otitis media. Treatment with carbenicillin alone and in combination with gentamicin.

Tympanocentesis was performed in 32 pediatric patients with chronic recurrent suppurative otitis media. The aspirate was cultured aerobically and anaerobically. Aerobes were isolated from ten patients (31.2%); anaerobes from one patient; and both aerobes and anaerobes from 21 patients (65.6%). There were 46 aerobic isolates. The aerobes commonly recovered were Pseudomonas aeruginosa (24 isolates) Proteus sp. (5) and Staphylococcus aureus (3). There were 32 anaerobes isolated including anaerobic gram-positive cocci (19 isolates) and Bacteroides sp., the latter of which included Bacteroides fragilis group and Bacteroides melaninogenicus (9). The patients were treated by parenteral carbenicillin 300 to 400 mg per kg per day given in four dosages administered for a period of 12 to 21 days (average 17 days). An aminoglycoside (gentamicin) was added in 15 patients. The clinical response was good in 17 patients and poor in 15. There were no side effects or adverse reactions noted during therapy. The above findings demonstrate the polymicrobial etiology of chronic recurrent suppurative otitis media and suggest that treatment directed against the aerobic and anaerobic isolates is efficacious in more than half of the cases.

Adolescent↗
PubMed1976

Bacterial interference by oropharynegeal and clinical isolates of anaerobic bacteria.

Anaerobic isolates were tested for bacterial inhibitory activity. Of 144 isolates, 102 were from oropharynegeal washings, and 42 were from clinical specimens. Thirteen facultative bacterial species (seven members of the Enterobacteriaceae and six species of gram-positive cocci) were used as indicators of inhibition. Eleven anaerobic species were isolated from oral secretions. All isolates of Bacteroides melaninogenicus, the most commonly recovered species, consistently inhibited several species of indicator bacteria. Bacteroides fragilis, Bacteroides oralis, and Peptostreptococcus anaerobius had unprecictable inhibitory activity, whereas most of the other oral anaerobes were noninhibitory. The 42 clinical species were generally noninhibitory.

Adult↗
PubMed1977

Acute bacterial meningitis at Boston City Hospital during 12 selected years, 1935-1972.

Data are presented on the occurrence of and mortality rate from acute bacterial meningitis at Boston City Hospital during 12 years between 1935 and 1972 selected in relation to the introduction of potent antibacterial agents. The most frequent causative organisms were Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae, but large proportions were caused by other gram-positive cocci and gram-negative bacilli. The greatest reduction in mortality rate after antibiotics became widely used was in patients with meningococcal and influenzal meningitis who were less than or equal to 19 years old. Less striking reductions occurred in cases of other etiologies in patients less than or equal to 59 years old, but in those greater than or equal to 60 years old, the mortality rate remained high, and the proportion of cases of meningitis in that age group more than doubled. Comparisons with similar data on all bacteremic infections are presented.

Acute Disease↗
PubMed1977

Activity of spectinomycin against anaerobes.

The in vitro inhibitory activity of spectinomycin was tested against various anaerobic bacteria. Different results were obtained with different media and with different initial pH's of the media. The highest minimum inhibitory concentrations for Bacteroides fragilis ([Formula: see text] 128 mug/ml) were obtained with the use of Wilkins-Chalgren agar (pH 7.2) and Brucella blood agar (pH 7.0). Brucella blood agar at higher pH's (7.4 and 8.0) and Mueller-Hinton and Diagnostic Sensitivity Test agars produced lower minimum inhibitory concentrations (32 and 64 mug/ml). This same relationship between spectinomycin activity and pH of the medium was, in general, observed with these media and other anaerobes, including isolates of B. melaninogenicus, Fusobacterium, gram-positive cocci, Clostridium perfringens, and C. ramosum. The variable results observed in this study and in two others make it difficult to predict the clinical usefulness of spectinomycin in the treatment of anaerobic infections. It is probably most appropriate to be guided by results obtained with Wilkins-Chalgren agar and the method proposed as a reference to the National Committee for Clinical Laboratory Standards. These results indicate that spectinomycin is not a potent inhibitor of B. fragilis or other clinically significant anaerobes.

Anaerobiosis↗
PubMed1978

Piperacillin: in vitro evaluation.

The in vitro activity of a new semisynthetic penicillin, piperacillin, was determined against 577 clinical isolates of gram-positive cocci and gram-negative bacilli. A concentration of 12.5 mug/ml inhibited 92% of isolates of Pseudomonas aeruginosa, 82% of Serratia marcescens, 73% of Escherichia coli, 61% of Klebsiella spp., and 42% of Enterobacter spp. Most Proteus spp. were extremely susceptible; over 85% were inhibited by 0.10 mug/ml. Piperacillin failed to inhibit the growth of gram-negative bacilli when large inocula were used. The type of media and pH had variable effects on the activity of piperacillin, depending upon the organism. Piperacillin was generally less active than PC-904 against gram-negative bacilli, but was consistently more active than carbenicillin and ticarcillin.

Bacteria↗
PubMed2026

Alternative quadruplex real-time PCR reactions for detection and discrimination of Streptococcus pneumoniae serotypes within serogroup 6.

UNLABELLED: Streptococcus pneumoniae causes significant morbidity and mortality worldwide, and serotyping is important to assess the burden of disease that is vaccine preventable. For serotyping, the Centers for Disease Control and Prevention (CDC) use a series of 12 real-time multiplex PCRs (rmPCRs) performed in quadruplex reactions; however, rmPCR reaction 5 (rmPCR-5) for serotypes 6A, 6B, 6C, and 6D often failed at low DNA concentrations. This study investigated the cause of rmPCR-5 failure and provided alternative rmPCRs to resolve this issue. Quadruplex rmPCR target sequences were compared to S. pneumoniae reference genomes. Reactions rmPCR-5 [6ABCD, 6AB, 6BD, and 6CD] and rm-PCR-11 [37, 10F, 11BC, and 18CFBA] were compared to alternative reactions rmPCR-A1 [6ABCD, 10F, 11BC, and 18CFBA] and rmPCR-A2 [37, 6AB, 6BD, and 6CD]. All rmPCRs were tested using 10-fold serial dilutions of DNA from representative serotypes, and analytical specificity was assessed using DNA from other S. pneumoniae serotypes or various streptococci and Gram-positive cocci. Failure of rmPCR-5 was associated with overlapping 6ABCD and 6BD targets. Separation of these targets in the alternative rmPCRs-A1 and rmPCR-A2 allowed sensitive and specific detection and discrimination of serotypes 6A, 6B, 6C, and 6D, without impacting the detection of serotypes 10F, 11BC, 18CFBA, and 37. This study highlights the importance of rigorous author and peer-review to avoid manuscript errors and unintended consequences. By explaining what caused rmPCR-5 failure and proposing alternative reactions rmPCRs-A1 and rmPCR-A2, this study demonstrates the value of scientific collaboration to ensure molecular assays best serve the scientific community. IMPORTANCE: Streptococcus pneumoniae is a bacterium that can cause life-threatening infections like pneumonia and meningitis, leading to millions of deaths worldwide each year. A key feature enabling S. pneumoniae to cause disease is its sugar coating, allowing it to avoid the immune system. These surface sugars are the target of S. pneumoniae vaccines. However, vaccines only protect against some sugars and understanding which ones are on the surface of S. pneumoniae is called "serotyping." The Centers for Disease Control and Prevention (CDC) have protocols that allow us to predict S. pneumoniae serotypes by looking at its DNA. We found errors in the CDC protocols and provided a simple solution to fix them. Ultimately, having accurate serotyping protocols allows us to know how much disease is preventable by vaccine, allows us to monitor how well vaccine are working, and helps develop new vaccines if needed.

Streptococcus pneumoniae↗
PubMed1977

Carfecillin: antibacterial activity in vitro and in vivo.

Carfecillin, the alpha-phenyl ester of carbenicillin, hydrolyses rapidly in the presence of serum or body tissues to liberate carbenicillin but hydrolysis is less rapid in aqueous solution. The activity of carfecillin in antibacterial tests in vitro depends upon the extent of hydrolysis to carbenicillin, and in conventional serial dilution tests carfecillin shows an antibacterial spectrum generally similar to that of carbenicillin due to extensive hydrolysis. However, in tests in which the extent of hydrolysis is reduced, carfecillin displays lesser activity than carbenicillin against gram-negative bacilli and greater activity against gram-positive cocci. In the presence of serum carfecillin is hydrolysed rapidly to carbenicillin and the activity shown is solely that of carbenicillin. Unlike carbenicillin, carfecillin is well absorbed in mice after oral administration, producing significant carbenicillin blood concentrations and the compound is as effective by the oral route in the treatment of various experimental mouse infections as is parenteral carbenicillin.

Administration, Oral↗
PubMed2026

Whole-Genome Sequencing Reveals Virulence and Antimicrobial Resistance Determinants of Lactococcus garvieae Causing Lactococcosis in Cage-Cultured Nile Tilapia (Oreochromis niloticus) in Thailand.

Lactococcosis is an important bacterial disease affecting farmed fish worldwide and is primarily associated with Lactococcus garvieae, Lactococcus petauri, and Lactococcus formosensis. In Thailand, information on L. garvieae infection in tilapia remains limited, particularly regarding genome-based identification, virulence determinants, and antimicrobial resistance profiles. This study characterized two L. garvieae isolates, AAHM-LG2501 and AAHM-LG2509, recovered from a lactococcosis outbreak in cage-cultured Nile tilapia (Oreochromis niloticus) in Ubon Ratchathani province, Thailand. Both isolates exhibited typical phenotypic characteristics of L. garvieae, including Gram-positive cocci, alpha hemolysis, positive capsule staining, and positive carbohydrate fermentation. Whole-genome sequencing confirmed both isolates as L. garvieae, with genome sizes of approximately 1.95 Mb and a G + C content of 38.9%. Genome-based taxonomic analysis supported species identification based on dDDH and ANI values, and both isolates were assigned to sequence type ST95 and serotype I. Virulence factor analysis identified 288 virulence-associated genes representing 97 virulence factors across 14 functional categories. Capsule-associated genes were prominent, together with genes involved in heme uptake, adhesion, hemolysis, stress survival, biofilm formation, and host adaptation. Ten capsule biosynthesis genes, including cpsABCFGKO, cps4A, and cps4I, as well as LPxTG cell wall anchor protein genes, were detected. Antimicrobial susceptibility testing showed resistance to nalidixic acid, oxolinic acid, and oxacillin, while reduced inhibition zones were observed for enrofloxacin and sulfamethoxazole-trimethoprim. Genome analysis identified predicted antimicrobial resistance determinants, including lsaD, vanT, vanY, and mdtA. Resistance-associated protein variants were detected in gyrA and gyrB, suggesting that target alteration may contribute to fluoroquinolone resistance. Overall, this study provides genome-level evidence of virulence and antimicrobial resistance determinants in L. garvieae from Thai tilapia and highlights the importance of whole-genome sequencing for accurate diagnosis, epidemiological surveillance, and disease management in aquaculture.

Animals↗
PubMed1976

Comparative in vitro activity of cephalosporins.

The in vitro activity of cephalexin, cephaloridine, cephalothin, cephapirin, cefoxitin, cephamycin C, cepharadine and cefazolin was determined against 443 isolates of bacteria. At a concentration of 12.5 mug/ml, all of the cephalosporins inhibited more than 60% of the isolates of Klebsiella pneumoniae. At the same concentration, cephalexin, cephaloridine, cephalothin, cephapirin, cephamycin C and cefazolin inhibited more than 90% of isolates of proteus mirabilis. All of the cephalosporins except cephalothin and cephapirin inhibited over 60% of isolates of Escherichia coli at a concentration of 12.5 mug/ml. Cefoxitin was the most active cephalosporin against gram-negative bacilli. There was substantial differences in the activity of cephalosporins against gram-positive cocci. Cephaloridine was the most active cephalosporin against these organisms. There was considerable fluctuation in the proportion of isolates of gram-negative bacilli susceptible to these cephalosporins from year to year, but there was no evidence to suggest that the number of resistant isolates was increasing.

Cephalosporins↗
PubMed1976

Susceptibility of Staphylococcus aureus, Streptococcus pyogenes and Diplococcus pneumoniae to antibiotics. Comparison of patterns in Poland and Federal Republic of Germany.

One hundred and eighty five strains of Gram-positive cocci were tested for susceptibility to 16 antibiotics, including some newer drugs, by agar dilution technique. Of these, 100 strains (50 each isolated in Poland and Germany) were Staphylococcus aureus, 55 Streptococcus pyogenes, and 30 Diplococcus pneumoniae. Previous investigations of streptococci and pneumococci isolated in Poland and Federal Republic of Grmany, revealed no differences in antibiotic-susceptibility patterns in both countries, which was not the case with staphylococci. Present study demonstrates further evidence for existence of differences in antibiotic-sensitivity of staphylococci, depending of their geographical origin, and presents actual state of susceptibility to antibiotics of Streptococcus pyogenes and Diplococcus pneumoniae.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Quantitative study and typization of aerobic bacteria in the conjunctival sacs of healthy eyes].

We carried out a qualitative and quantitative bacteriological research into the conjunctives of 220 subjects in good health mostly women (180) exempt from recent or previous eyes diseases. In order to gather conjunctival bacteria we employed with a few variations Hadley's et al. (1973 [12]) method. Among the calculated bacterial flora we found as the most numerous ones Staphylococcus epidermidis (mean valor 1960/ml), then Streptococci (480/ml), Micrococci (465/ml), Diphteroides (360/ml), Enterococci (77/ml) and numerous (700/ml) Gram-positives Cocci like Sarcina, Micrococcus tetragenes, Diplococcus, and very rarely bacterial genera Gram-negatives or Iphomycetes, also numerically inferior as regards the researches of other Authors, because owen study is carried by into eyes exempt from diseases.

Adolescent↗
PubMed1979

Anaerobic pulmonary infections.

The main cause of anaerobic pulmonary infections is aspiration of saliva, upper airway secretions or gastric content. Predisposing conditions include prominent dental disease, chronic upper respiratory tract infections and reduced consciousness. Fusobacterium nucleatum, Bacteroides melaninogenicus and anaerobic Gram-positive cocci are the most frequently encountered organisms. The clinical presentations are lung abscess, lung gangrene and empyema, which all tend to take a slow and indolent course. Preferred localization are dependent lung segments, most often on the right side. For bacteriological examination in these infections, only transtracheal aspirate and aspirate from the lung or pleural space are considered adequate. In 26 cases of empyema treated in our hospital during the last 3 years, adequate specimens had been taken in 19. Fifteen had been adequately examined, and anaerobes were cultured in 6. Among 29 abscesses treated during the same period, adequate specimens had been taken in only 14, and 11 had been properly examined. Seven specimens grew anaerobes on culture. In prospective studies of transtracheal aspirate in 15 chronic bronchitics without emphysema, anaerobes were not demonstrated. In 11 patients with bronchiectasis, anaerobic bacteria were cultured in 3. Finally, no anaerobic bacteria could be demonstrated in the transtracheal aspirate from 76 patients with acute exacerbation of chronic bronchitis. Anaerobic, pulmonary infections do not represent an intriguing medical problem in our region. However, knowledge of these infections is necessary to secure adequacy in collection of specimens and in their bacteriological examination.

Bacterial Infections↗
PubMed1976

[Bacteriological findings in materials from patients with nonspecific odontogenic infections].

The results of bacteriological studies made between 1964 and 1971 by workers at the Varia Laboratory, Institute of Medical Microbiology on 767 patients treated at the Clinic of Gnathofacial Surgery, Department of Medicine, Friedrich Schiller University at Jena, are evaluated. The testees (x=275) were included in groups with specific diagnoses, and a breakdown was made according to the detection of aerobic pus-forming germs. Gram-positive cocci were detected in 92% of the cases and their pathogenetic representatives, 76,5% of the cases. Rodshaped germs (Enterobacteriaceae, Pseudomonas) were observed only in 37,9% of the cases. Staphylococcus aureus, which accounted for 62,5%, was the most frequently observed species. It was followed, in order of frequency of detection, by greening streptococci and Staphylococcus epidermidis. Monoinfection was far more frequently observed than multi-infection. Also, the problems associated with the differentiation of streptococci are pointed out since other investigators found streptococci to be the most frequent agents producing odontogenic infections.

Bacterial Infections↗
PubMed1979

Intramembranous localization of bacteria in beta-hemolytic group B streptococcal chorioamnionitis.

An unusual pathologic finding consisting of large colonies of bacteria, localized immediately beneath the epithelial layer of the amnion, has been observed in association with an example of group B beta-hemolytic streptococcal chorioamnionitis. Postpartum endometritis as well as neonatal sepsis and meningitis occurred. Histologic examination of the umbilical cord and placenta revealed routine features of intraamniotic inflammation, but the membranes were characterized by the presence of unusual darkly staining deposits of material immediately beneath the amniotic epithelium. Subsequent special stains revealed these to be colonies of gram-positive cocci. We have been unable to find a previous description of this observation in association with streptococcal or with other types of chorioamnionitis.

Adult↗