Microbiological spectrum and susceptibility pattern of clinical isolates from the neonatal unit in a single medical center.

BACKGROUND: Infections are a frequent and significant cause of morbidity and mortality in neonatal units. The bacterial pathogens and their susceptibility patterns should be monitored in hospital settings. The aim of the study was to describe the distribution of the bacterial agents and their antibiotic resistant and susceptibility patterns in the Special Neonatal Care Unit (SNCU). MATERIAL AND METHODS: A retrospective analysis of results of microbiologically tested samples (blood, cerebrospinal fluid, urine, stool, eye excretions, external ear swabs, nasopharyngeal swabs and skin swabs) taken from newborns hospitalized in one SNCU in Warsaw (Poland) was conducted. The period analyzed was from July 1st, 2010 to December 31st, 2010. RESULTS: A total of 838 cultured samples were collected in the period analyzed. Three hundred seventy three of them (44.5%) were positive. The majority of the cultured microorganisms were classified as colonization: 338/373 (91%) strains. Gram negative bacteria were predominant colonizing flora: 227/338 (67%) strains. Gram positive bacteria were predominant causative agents in newborns with infections: 26/35 (74%) strains. 57.9% of Escherichia coli isolates were resistant to amoxicillin and ampicillin. 100% of Klebsiella pneumoniae were resistant to amikacin and netilmicin. Staphylococcus aureus methicillin resistant strains were cultured in 2.7% of cases. CONCLUSIONS: Gram negative species continue to be predominant agents of neonatal colonizing flora while gram positive bacteria remain important causative agents for symptomatic infections. Continuous monitoring of bacterial flora and its antibiotic susceptibility pattern is necessary to provide a successful antibiotic policy. Current results may be used for future national and international comparison.

[Aminoglycoside resistance of enterobacteria isolated from urinary infections in surgical departments]. / Rezistenta la aminoglicozide a enterobacteriilor izolate din infectii urinare în sectii cu profil chirurgical.

The aim of the study was to determine the aminoglycosides resistance of Enterobacteriaceae strains isolated from urocultures. Identification of the germs was performed by the API system (BioMerieux) and susceptibility tests was performed by disk-diffusion test (CLSI standards) and with API strips. For detecting the resistance to aminoglycosides we used gentamicin, tobramycin, netilmicin and amikacin. From 2500 urine samples we isolated 673 microbial strains, from which 531 were Enterobacteriaceae, especially E. coli, 57.62% and Klebsiella pneumoniae pneumoniae, 27.68% strains. We observed natural maintained sensibility to aminoglycosides at 55.17% from all the strains we have studied The high prevalence of aminoglycosides resistance of Enterobacteriaceae strains is explained by prolonged antibiotic therapy of patients with invasive diagnostic and therapeutic procedures. A rational policy in prescribing antibiotics in this department is therefore mandatory.

[Generalized tetanus complicating a traditional medicine applied for snakebite]. / Tétanos généralisé compliquant un traitement traditionnel instauré après une morsure de serpent.

In many of Africa's rural areas, snakebite victims often resort to traditional healers for first line treatment. This may be source of infectious complications. We report a case of generalized tetanus which occured after 15 days in a 13-years old boy who had applied a traditional, plant-based concoction on a snake bite. He presented with trismus, generalized contractures and fever extended musculo-aponevrotic necrosis of the right upper limb, without loss of consciousness. The only accompanying biological sign was an increased leukocyte count (11,200/mm3) with a predominance of neutrophils (84%). Platelets count, creatinin and AST/ALT titers and haemostasis were all normal, as was the radiogram of the right hand. The clinical outcome was favourable after 3 weeks hopital care (antibiotic, muscle relaxants, antitetanus serotherapy and local wounds care). This clinical observation shows that traditional care for snake bite wounds can be an entry point for tetanus. Appropriate treatment of snake bites in a hospital setting is of the utmost importance, in addition to vaccination against tetanus, in order to reduce the incidence of tetanus in African countries.

[Pseudomonas and acute external otitis. Results of a microbiological study in patients without previous antibiotic treatment]. / Pseudomonas y otitis externa aguda. Resultados de un estudio microbiológico en pacentes sin tratamiento antibiótico previo.

We report the results of a microbiological clinic study that was performed by our ENT Department between years 2000 and 2001 whose main objective was to determine, in Badajoz Area of Health, which bacteria were involved in the acute diffuse external otitis of patients without previous antibiotic treatment (two weeks before obtaining the samples). Of 79 isolated microorganisms in 62 patients that fulfilled the requirements established Pseudomonas, mainly P. Aeruginosa, represented a 46.83% altogether followed by Staphylococcus (18.98%). In almost one fourth part of the cases strains of associated fungi were identified.

Antimicrobial-induced endotoxaemia in patients with sepsis in the field of acute pyelonephritis.

BACKGROUND: In vitro results have shown that antimicrobial agents may induce the Gram-negative bacteria to release endotoxins (LPS), which in turn, could trigger the secretion of cytokines from monocytes. AIMS: To compare the effect of cefuroxime, netilmicin or ciprofloxacin on serum levels of LPS and tumour necrosis factor-alpha (TNFalpha). METHODS: Seventy-four patients with acute pyelonephritis caused by Gram-negative bacteria and signs of sepsis were randomly assigned to receive one of three intravenous regimens of cefuroxime, netilmicin or ciprofloxacin. Blood samples were collected before therapy and at specified time intervals for 96 hours after the initiation of treatment for the determination of serum levels of LPS and of TNFalpha. RESULTS: Patients treated with cefuroxime presented an early peak of LPS and of TNFalpha in serum two hours after the initiation of treatment compared to the other study groups. After that time interval, concentrations of LPS and TNFalpha were similar in all the study groups. Fever accompanied by endotoxaemia was still detected for 48 hours after the start of therapy in 36, 37.5 and 36% of patients treated with cefuroxime, netilmicin and ciprofloxacin respectively. The corresponding figures for these agents at 72 hours were 28, 12.5 and 24%, respective and 12, 4.2 and 4% at 96 hours (P value not significant). CONCLUSIONS: With the exception of an early peak in the serum levels of LPS and TNFalpha in patients treated with cefuroxime, no significant difference could be detected amongst the study groups as far as their effect on serum levels of LPS and TNFalpha were concerned. This suggests that these three antimicrobial agents may be administered safely at the early stages of sepsis.

Renal function and effect of aminoglycoside therapy during the first ten days of life.

The effect of aminoglycoside administration on kidney functional maturation was evaluated in groups of 30 preterm and 30 fullterm infants who were treated for 7 days because of suspected infection. One of three different aminoglycosides was administered to each subgroup of ten preterm and ten fullterm infants. Changes in tubular function in groups of ten preterm and ten fullterm infants who were not given antibiotics were also compared. The mean gestational age for preterm infants from 32.5 to 33.6 weeks and for fullterm infants between 39.2 and 39.5 weeks. The renal tubular function was assessed by examining the fractional excretion of sodium (FENa), potassium (FEK), phosphorus (FEP), magnesium (FEMg) and uric acid (FEUA) as well as by the urinary excretion of calcium as the calcium/creatinine (UCa/UCr) ratio. Gentamicin affected the normal plasma creatinine (PCr) decline in both treated groups (fullterm and preterm). Disturbances in FENa and UCa/UCr were more pronounced in treated preterm than in fullterm infants especially after netilmicin and gentamicin administration. FEMg was significantly affected in preterm infants treated with gentamicin. The findings of this study indicate that the effect of aminoglycosides on tubular function is dependent upon kidney maturity and the type of the aminoglycoside used for therapy.

[Antimicrobial activity of ciprofloxacin and netilmicin compared to various antibiotics in Lome, Togo]. / Activité antimicrobienne de la ciprofloxacine et de la nétilmicine comparée à celle de divers antibiotiques à Lomé, Togo.

We report the antimicrobial activity of ciprofloxacin and netilmicin on 577 strains such as S. aureus, Pseudomonas, E. coli, Salmonella, Proteus, Klebsiella and Enterobacter. Isolation and identification were performed by standard methods. Disk diffusion tests were performed to evalute the susceptibility. The percentage resistance to ciprofloxacin for bacteria was: E. coli = 15%, Enterobacter = 13%, Proteus = 10%, Pseudomonas = 9%, S. aureus and Klebsiella = 4%. The percentage resistance to netilmicin for bacteria was: Pseudomonas = 29%, Proteus = 26%, S. aureus = 21%, Enterobacter = 16%, Klebsiella = 14% and E. coli = 5%. The antimicrobial activity of ciprofloxacin and netilmicin was higher than that of others antibiotics.

Topical netilmicin compared with tobramycin in the treatment of external ocular infection.

In a pilot double-blind, randomized, prospective controlled study the effectiveness and safety of 0.3% netilmicin ophthalmic solution were compared with those of 0.3% tobramycin in treating external bacterial ocular infections in 45 eligible patients. The treatment with both study medications resulted in a significant (p < 0.001, Wilcoxon test) reduction in the mean cumulative score of the signs and symptoms. However, no statistically significant differences were observed between the two groups. The clinical improvement rate was almost complete with either antibiotics. There was a statistically positive trend in the netilmicin group with regard to the microbiological improvement that was achieved in (87% of the netilmicin patients) compared with 77% of the tobramycin patients (77%). Antibiotic sensitivity revealed that 84% of the organisms isolated were sensitive to netilmicin whereas only 64% of them were sensitive to tobramycin. Only minor adverse events occurred in patients treated with either netilmicin or tobramycin. In conclusion, this study demonstrates that netilmicin is a promising new antibiotic for treating external ocular infections.

[Clinical, bactericidal and pharmacological evaluation of the effects of netromycin]. / Klinicheskaia, bakteritsidnaia i farmakologicheskaia otsenka deistviia netromitsina.

AIM: To analyze clinical, bactericidal effectiveness and pharmacokinetics of wide-spectrum antibiotic netromycin (NM). MATERIALS AND METHODS: The trial entered 29 patients: 21 with bronchopulmonary diseases (pneumonia and chronic bronchitis), 5 with exacerbation of chronic pyelonephritis, 2 with infectious endocarditis and 1 with peritonsillar abscess. RESULTS: Microbiologically, most of the agents (80.36%) showed sensitivity to NM. Pharmacologically, NM persisted long in blood serum and sputum irrespective of the administration mode. Positive clinical dynamics after NM treatment was achieved in all the patients but one who had a peritonsillar abscess. CONCLUSION: NM is highly active against both gram-positive and gram-negative flora. Side effects are minimal.

[A series of clinical study on netilmicin].

OBJECTIVE: To evaluate the clinical effects, pharmacokinetics, post-antibiotic effect (PAE) and toxicity of netilmicin as a single daily dose in the treatment of lower respiratory tract infection. METHODS: 48 cases were divided into 3 groups: In the first group, Netilmicin(6 mg.kg-1.d-1) was administered in a single daily dose; in the second group, netilmicin (200 mg/d) was combined with cefazolin (3 g, Q12 h); and in the third control group, the combination of cefazolin and Amikacin was used. Pharmacokinetics were studied in 7 patients using the TDX system, and PAE induced by Netilmicin was determined by the Avantage microbiologic system. Clinical symptoms, laboratory studies, chest X-rays, and side effects were observed. RESULTS: The overall clinical effects of the first group were better than those of the third group. The mean serum concentration of netilmicin was 27.23 mg/L, the valley serum concentration was 0.23 mg/L, T1/2 beta was 5.059 h, AUC was 70 micrograms.h-1.ml-1.netilmicin at concentrations 0.5, 1.0 and 4 times the MIC showed different degrees of PAE against 4 strains of bacterium. Nephrotoxicity and ototoxicity were not found in the treatment group. CONCLUSIONS: Netilmicin in a single daily dose resulted in a high peak serum concentration and big AUC. As a concentration-dependent bactericidal agent, netilmicin showed a longer PAE and better therapeutic effects.

Increased burn patient survival with once-a-day high dose teicoplanin and netilmicin. An Italian multicenter study.

This is the final report of a large, controlled, multicenter Italian study on immuno- and chemotherapy in adult patients with burns affecting 20 to 95% of total body surface area (mean 35%). The antibiotic treatment of burn patients consisted of topical silver sulfadiazine, short-term antimicrobial chemoprophylaxis with pefloxacin (800 mg i.v. qd) for the first 4 days and polychemotherapy with teicoplanin (800 mg i.v. qd) together with netilmicin (300 mg i.m. qd) in one or more cycles of 5-12 days. At random, half of the patients received thymostimulin, 70 mg i.m. qd for the first month and every other day thereafter. The analysis at completion of 634 valid cases showed that when the results are stratified by means of the Roi risk index, 396 of the 530 patients who contracted wound infection (84%) after chemoprophylaxis were in the first three categories and a mean of 95% survived. Of the remaining 134 patients (Roi index 4-5) only 50% survived. There was no difference in survival of the immunotherapy group in comparison with the parallel group without thymostimulin. The short-term antimicrobial prophylaxis prevented wound infection in only 104 of 634 patients (16%) and they were at low risk (84% Roi index 1). Of the bacterial pathogens involved in septic complications Staphylococcus aureus and Pseudomonas aeruginosa were prevalent (86%): eradication was achieved in 43% of patients and clinical cure or improvement were seen with combination chemotherapy in 64% of all patients, mainly with only one treatment cycle. This value increased to 79% for the 395 protocol-complying patients and went down to 20% in the 135 non-compliers. The total survival of complier and non-complier patients was 447 of the 530 valid patients (84%). The overall mortality of the 634 evaluable patients was 13.1%, ranging from less than 2% to 68%. Burn mortality was directly proportional to the percentage of burned body surface area, to increasing age and other variables of the Roi index, a 50% mortality being associated with a 72.5% total body surface area burned. Normoergic burn patients had a mortality rate of 9.1% versus 35.7% in anergic patients.

Ciprofloxacin treatment of bacterial endocarditis involving prosthetic material after cardiac surgery.

Two children with cyanotic congenital heart disease and Gram negative bacterial infection of prosthetic material after cardiac surgery were treated successfully with oral ciprofloxacin, initially in combination with netilmicin. The use of oral ciprofloxacin allowed prolonged outpatient treatment to be given, avoiding the need for intravenous access and early repeat surgery.

Pharmacokinetics and bactericidal activity of a single daily dose of netilmicin in the treatment of CAPD-associated peritonitis.

Single daily dosage of netilmicin is generally accepted in systemic infections, due to biphasic bactericidal activity and prolonged postantibiotic effect of aminoglycosides. Since little is known about the efficacy of single daily intraperitoneal application of netilmicin in the treatment of CAPD-associated peritonitis, we conducted this prospective study. Seven patients with CAPD-associated peritonitis were treated with a single daily dose of netilmicin (loading dose 1.5 mg/kg, followed by 40 mg/21 bag/day). Serum and intraperitoneal levels as well as bactericidal activity of netilmicin against Acinetobacter baumanii, E. coli and Pseudomonas aeruginosa were measured for 48 hours. Serum and peritoneal levels widely varied among the patients due to different interindividual plasma clearance of netilmicin. The intraperitoneal antibacterial action of netilmicin was decreased, more over, substantial differences in the bactericidal activity were found among the patients. However, with high initial netilmicin levels sufficient bactericidal activity was found for Acinetobacter and E. coli, but not for Pseudomonas aeruginosa. Hence, a single daily dosage of netilmicin can be a suitable treatment of CAPD-associated peritonitis, only if the dose is adapted according to the first serum and peritoneal levels. In infections with Pseudomonas aeruginosa higher peritoneal levels of netilmicin and the combination with other antibiotics will be needed for a sufficient peritoneal bactericidal activity.

Comparison of the bactericidal action of amikacin, netilmicin and tobramycin in free and liposomal formulation against Pseudomonas aeruginosa.

The rates at which free, cationic and anionic liposomal forms of amikacin, netilmicin and tobramycin kill Pseudomonas aeruginosa were studied in vitro. Control inocula with no antibiotic yielded 6.76, 9.53 and 9.74 log CFU/ml at 0, 6 and 24 h, respectively. Empty anionic or cationic liposomes had no effect on bacterial growth. The killing rates of free antibiotics against the bacterial strain were not enhanced by the addition of either empty anionic or cationic liposomes. After 6 and 24 h of exposure at 1, 2 and 4 times the minimum inhibitory concentrations, free amikacin, netilmicin and tobramycin demonstrated a more rapid bactericidal effect than encapsulated anionic or cationic liposomes. The killing rates of liposomal aminoglycosides were lower than those of free aminoglycosides at identical concentrations, suggesting that only fractions of the encapsulated drugs were released from liposomes.

Vancomycin or vancomycin plus netilmicin for methicillin- and gentamicin-resistant Staphylococcus aureus aortic valve experimental endocarditis.

Using a rabbit model of aortic valve endocarditis, we studied the efficacy of vancomycin alone or in combination with netilmicin and/or rifampin against a methicillin- and gentamicin-resistant strain of Staphylococcus aureus (MGRSA). Antibiotics were given for 6 to 12 days, as follows: vancomycin (15 mg/kg of body weight every 12 h [BID] intravenously), vancomycin plus netilmicin (2.5 mg/kg BID intramuscularly), vancomycin plus rifampin (10 mg/kg BID intramuscularly), and vancomycin plus netilmicin plus rifampin at the same routes, dosages, and schedules mentioned above. Netilmicin was given to two additional groups at a higher dosage (6 mg/kg every 24 h intramuscularly) alone or in combination with vancomycin (15 mg/kg BID intravenously) for 12 days. All regimens resulted in undetectable bacterial counts in a significant proportion of vegetations (except netilmicin alone) or reduced the bacterial counts in the vegetations compared with the counts in the untreated controls (P<0.01 to P<0.001). No resistance to rifampin or netilmicin developed during therapy. It is concluded that in the treatment of experimental aortic valve endocarditis caused by MGRSA (i) vancomycin as monotherapy is as efficacious as the triple combination, (ii) the addition of netilmicin (once daily or BID) to vancomycin does not improve the efficacy of the latter antibiotic, even in the presence of rifampin, and (iii) a 12-day course in more effective than a 6-day one, but not at a statistically significant level.

[Standardization of conditions for the evaluation of effectiveness of antibacterial drugs in pneumonic plague in sacred baboons]. / Standartizatsiia uslovii otsenki éffektivnosti antibakterial'nykh preparatov pri lechenii legochnoi chumy u obez'ian pavianov gamadrilov.

The signs of pneumonic plague in sacred baboons infected by aerosol are: fever, hurried breathing, depression and constantly increasing bacteremia. Some infected animals isolate the plague microbes while coughing and thus could be a source of the infection. By the clinical and pathomorphological signs, pneumonic plague in sacred baboons is similar to that in humans which makes it possible to use the animals in the development of schemes for special prophylaxis and treatment of the disease. In efficacy estimation of antibacterial drugs sacred baboons should be infected by aerosol by highly virulent strains of Y. pestis in doses of 1.10(4)-1.10(5) live microbes. The treatment of the animals should be started from the moment of the rectal temperature increase to 39.5 degrees C or higher after collecting the blood specimens for the bacteriological tests. It was shown that a two-day course of the treatment with antibacterial drugs was not efficient in the animals with pneumonic plague. The use of streptomycin, gentamicin, netilmicin or ciprofloxacin for 7 days cured all the infected animals. The use of streptomycin in the therapeutic doses was not efficient in the animals whose blood specimens of 1 cm3 contained 4.10(4) or more plague microbes by the moment when the treatment was started.

Renal function in premature infants during aminoglycoside therapy.

The effect of three different aminoglycosides on renal function was evaluated in 30 premature infants of similar gestational age who were treated within 24 h of birth with either amikacin (10 infants, group A), gentamicin (10 infants, group B) or netilmicin (10 infants, group C), for a period of 7 days. Ten infection-free premature infants of similar post-conceptional age were used as controls. Serial determinations of plasma creatinine concentration (PCr), as well as the fractional excretion of sodium (FENa), potassium, magnesium (FEMg), phosphate (FEP) and uric acid (FEUA), and the urinary excretion of calcium (UCa/UCr ratio) were assessed before, during and after treatment. During the treatment period a significant increase in FENa, FEMg and UCa/UCr was observed in group B (P < 0.05 and P < 0.01, respectively) and an increase in FENa and UCa/UCr in group C (P < 0.01) compared with controls. These disturbances were observed with trough concentrations of aminoglycosides but were accentuated at peak serum concentrations and were restored to normal 2 days after stopping therapy. In addition, a significant correlation was demonstrated between FENa, FEMg and UCa/UCr ratio in treated patients. PCr levels decreased similarly in all patient groups, but in 8 of 30 infants (27%) they remained elevated and returned to control values only 10 days after stopping therapy. Such renal functional disturbances, although transient, may result in significant electrolyte and mineral imbalance in the sick premature infant.